A HYDROGEN GENERATOR OF A VEHICLE

AND

A METHOD FOR CONTROLLING A HYDROGEN GENERATOR OF A VEHICLE

TECHNICAL FIELD

Various embodiments relate to a control system for a hydrogen generator of a vehicle and a method for controlling a hydrogen generator of a vehicle.

BACKGROUND

Hydrogen generators, also know as hydrogen enhancement products, may be used to generate hydrogen by electrolytic separation of a fluid, for example, pure water or a solution. A hydrogen generator may perform electrolytic separation using one or more types of agents in the fluid. The agent may be an electrolyte and/or a catalyst. The hydrogen generated by the hydrogen generator may be used to improve the combustibility of a fuel, such as, for example, gasoline, diesel or the like. For example, the hydrogen generator may be configured to mix generated hydrogen with the fuel before the fuel is used by an engine. Various hydrogen generators are available for installation into a vehicle and for operation with an engine of the vehicle. The vehicle may be a car, a boat or some other powered means of transportation. The engine may be an internal combustion engine.

A hydrogen generator may be powered by a battery of the vehicle. For example, the hydrogen generator may be turned on by activating an electric relay through-which a fixed voltage may be provided from the battery. Accordingly, hydrogen generation may only be a function of the mechanical construction of the electrodes and the agents in the fluid.

SUMMARY

A first aspect provides a control system for a hydrogen generator of a vehicle, the control system comprising: a controller configured to receive a hydrogen indication, the hydrogen indication being a measure of hydrogen generated by the hydrogen generator, a voltage supplier configured to supply a voltage to the hydrogen generator, wherein the controller is operable to cause the voltage supplier to vary the voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

In an embodiment, the controller is configured in use to cause the voltage supplier to vary the voltage supplied to the hydrogen generator so that the hydrogen indication is maintained above a first predetermined value.

In an embodiment, the first predetermined value is greater than zero.

In an embodiment, the controller is configured in use to cause the voltage supplier to vary the voltage supplied to the hydrogen generator so that the hydrogen indication is maintained below a second predetermined value.

In an embodiment, the voltage supplier is configured in use to convert a supply voltage from a battery into a converted voltage, wherein the converted voltage is the voltage supplied to the hydrogen generator.

In an embodiment, the controller is configured in use to cause the voltage supplier to vary the voltage supplied to the hydrogen generator by controlling the voltage supplied to the hydrogen generator according to a predetermined cycle.

In an embodiment, the controller is configured in use to vary a length of the predetermined cycle in dependence on the hydrogen indication.

In an embodiment, the controller is configured in use to vary a duty cycle of the predetermined cycle in dependence on the hydrogen indication.

In an embodiment, the controller is configured in use to cause the voltage supplier to increase the voltage supplied to the hydrogen generator in dependence on the hydrogen indication. In an embodiment, the controller is configured in use to cause the voltage supplier to decrease the voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

In an embodiment, the control system further comprises: a shut-off sensor configured in use to detect a value of a shut-off parameter and generate from the detection a shut- off parameter value indication for provision to the controller; wherein the controller is configured in use to receive the shut-off parameter value indication and cause the voltage supplier to terminate the voltage supplied to the hydrogen generator in dependence on a comparison between the shut-off parameter value indication and a corresponding predetermined shut-off threshold.

In an embodiment, the shut-off parameter is at least one of the following: a temperature of the hydrogen generator, a hydrogen pressure in the hydrogen generator, a working level of an engine of the vehicle, a speed of the vehicle.

In an embodiment, the shut-off parameter is a charge level in the battery.

In an embodiment, the working level of the engine of the vehicle is a number of revolutions per minute (RPM) of the vehicle's engine.

In an embodiment, the control system further comprises: an overdrive sensor configured in use to detect a value of an overdrive parameter and generate from the detection an overdrive parameter value indication for provision to the controller; wherein the controller is configured in use to receive the overdrive parameter value indication and cause the voltage supplier to vary the voltage supplied to the hydrogen generator in dependence on a comparison between the overdrive parameter value indication and a corresponding predetermined overdrive threshold.

In an embodiment, the overdrive parameter is at least one of the following: a gradient at which the vehicle is moving, a mass of a load being moved by the vehicle. In an embodiment, the hydrogen indication is an indication of a current drawn by the hydrogen generator.

In an embodiment, the control system further comprises a sensor for monitoring an attribute of the hydrogen generator, the sensor being configured in use to generate the hydrogen indication based on the monitored attribute and send the hydrogen indication to the controller.

In an embodiment, the sensor is a current sensor configured in use to monitor the current drawn by the hydrogen generator and generate from the monitored current the hydrogen indication for provision to the controller.

In an embodiment, the current drawn by the hydrogen generator is an average current of multiple cycles.

A second aspect provides a method for controlling a hydrogen generator of a vehicle, the method comprising: receiving a hydrogen indication, the hydrogen indication being a measure of hydrogen generated by the hydrogen generator; varying a voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

In an embodiment, varying the voltage supplied to the hydrogen generator comprises varying the voltage supplied to the hydrogen generator to maintain the hydrogen indication above a first predetermined value.

In an embodiment, the first predetermined value is greater than zero.

In an embodiment, varying the voltage supplied to the hydrogen generator comprises varying the voltage supplied to the hydrogen generator to maintain the hydrogen indication below a second predetermined value.

In an embodiment, the method further comprises converting a supply voltage from a battery into a converted voltage, the converted voltage being the voltage supplied to the hydrogen generator. In an embodiment, varying the voltage supplied to the hydrogen generator comprises controlling the voltage supplied to the hydrogen generator according a predetermined cycle.

In an embodiment, the method further comprises varying a length of the predetermined cycle in dependence on the hydrogen indication.

In an embodiment, the method further comprises varying a duty cycle of the predetermined cycle in dependence on the hydrogen indication.

In an embodiment, varying the voltage supplied to the hydrogen generator comprises increasing the voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

In an embodiment, varying the voltage supplied to the hydrogen generator comprises decreasing the voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

In an embodiment, the method further comprises: detecting a value of a shut-off parameter; and terminating the voltage supplied to the hydrogen generator in dependence on a comparison between the detected value of the shut-off parameter and a corresponding predetermined shut-off threshold.

In an embodiment, the shut-off parameter is at least one of the following: a temperature of the hydrogen generator, a hydrogen pressure in the hydrogen generator, a working level of an engine of the vehicle, a speed of the vehicle.

In an embodiment, the shut-off parameter is a charge level in the battery.

In an embodiment, the working level of the engine of the vehicle is a number of revolutions per minute (RPM) of the vehicle's engine.

In an embodiment, the method further comprises: detecting a value of an overdrive parameter; and varying the voltage supplied to the hydrogen generator in dependence on a comparison between the detected value of the overdrive parameter and a corresponding predetermined overdrive threshold.

In an embodiment, the overdrive parameter is at least one of the following: a gradient at which the vehicle is moving, a mass of a load being moved by the vehicle.

In an embodiment, the hydrogen indication is an indication of a current drawn by the hydrogen generator.

In an embodiment, the method further comprises: monitoring an attribute of the hydrogen generator, generating the hydrogen indication based on the monitored attribute.

In an embodiment, the monitored attribute is the current drawn by the hydrogen generator.

In an embodiment, the current drawn by the hydrogen generator is an average current of multiple cycles.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by way of example only, and in conjunction with the drawings, wherein like reference signs relate to like components, in which:

Figure 1 illustrates a schematic diagram of a control system for a hydrogen generator of a vehicle in accordance with an embodiment;

Figure 2 illustrates a flow diagram of a method for controlling a hydrogen generator of a vehicle in accordance with an embodiment; Figure 3 illustrates a schematic diagram of a control system for a hydrogen generator of a vehicle in accordance with an embodiment;

Figure 4A and Figure 4B illustrate flow diagrams of a method for controlling a hydrogen generator of a vehicle in accordance with the embodiment of Figure 3; and

Figure 4C, Figure 4D, and Figure 4E show a method for current regulation which may be applied in the embodiment of Figure 3.

DETAILED DESCRIPTION

Various embodiments relate to a control system for a hydrogen generator of a vehicle and a method for controlling a hydrogen generator of a vehicle.

Referring to Figure 1, there is shown a schematic diagram of a control system 100 for a hydrogen generator 200 of a vehicle 300 in accordance with an embodiment. It is to be understood that in the present embodiment, the vehicle is a car; however, in some other embodiments, the vehicle could be a different means for powered transportation, such as, for example, a different type of land-craft, or a type of water- craft or air-craft. In an embodiment, the vehicle is a boat, a truck, a motorcycle, an all- terrain vehicle, a jet ski or the like.

In an embodiment, the control system 100 may comprise a controller 10 and a voltage supplier 20. The controller 10 may be in communication with the voltage supplier 20 such that the voltage supplier 20 can receive control signals from the controller 10 and perform operations in dependence thereon. The controller 10 may be configured to receive a hydrogen indication. The hydrogen indication may provide an indication of a quantity of hydrogen being generated by the hydrogen generator 200. For example, the hydrogen indication may be a direct measure of hydrogen generated. Alternatively, the hydrogen indication may be an indirect measure, i.e. a measure of some other variable which varies in dependence on the hydrogen generated. Considering direct measurements, the hydrogen indication may be a measure of an amount of hydrogen generated by the hydrogen generator 200. In an embodiment, the hydrogen indication may be a measure of a flow rate of hydrogen produced by the hydrogen generator 200. For example, a hydrogen flow rate sensor may be in communication with an outlet of the hydrogen generator 200 and the hydrogen flow rate sensor may be configured in use to determine a flow rate of hydrogen leaving the hydrogen generator and provide a corresponding flow rate indicator (i.e. hydrogen indication) to the controller 10. In an embodiment, the hydrogen indication may be a measure of a pressure of hydrogen generated by the hydrogen generator 200. For example, a hydrogen pressure sensor may be in communication with the hydrogen generator 200 and the hydrogen pressure sensor may be configured in use to determine a pressure of hydrogen in the hydrogen generator and provide a corresponding hydrogen pressure indicator (i.e. hydrogen indication) to the controller 10.

Considering indirect measurements, the hydrogen indication may be an indication of a current drawn by the hydrogen generator. In an embodiment, the current may be an average current of multiple cycles. For example, a current sensor may be in communication with an electrical path to the hydrogen generator 200 and the current sensor may be configured in use to determine a current drawn by the hydrogen generator 200 and provide a corresponding current indicator (i.e. hydrogen indication) to the controller 10.

Accordingly, embodiments may comprise a sensor in communication with the controller and configured in use to monitor an attribute of the hydrogen generator. The sensor may be further configured in use to send a corresponding attribute indicator to the controller 10 so that the controller 10 can control the operation of the voltage supplier 20 in dependence thereon.

In an embodiment, the voltage supplier 20 may be configured to supply a voltage to the hydrogen generator 200. For example, the voltage supplier 20 may be a voltage source, for example, a battery capable of providing a variable supply voltage to the hydrogen generator 200. Alternatively, the voltage supplier 20 may be a voltage converter that is in communication with a battery and capable of converting a supply voltage from the battery into a converted voltage. The converted voltage may be the voltage supplied to the hydrogen generator 200. The supply voltage from the battery may be a fixed voltage. The converted voltage from the voltage converter may be a variable voltage. However, it is to be understood that in some other embodiments, the voltage supplier may be another device, or other devices, which is/are capable of providing a variable voltage supply to the hydrogen generator 200.

In an embodiment, the controller 10 may be operable to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator 200 in dependence on the hydrogen indication received by the controller 10. For example, if the controller 10 determines from the hydrogen indication that the amount of hydrogen being generated by the hydrogen generator is reducing or is below a preset threshold, the controller 10 may cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator 200 to increase hydrogen generation. Additionally or alternatively, if the controller 10 determines from the hydrogen indication that the amount of hydrogen being generated by the hydrogen generator is increasing or is above a preset threshold, the controller 10 may cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator 200 to decrease hydrogen generation.

In an embodiment, the controller 10 may be operable to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator in various different ways as set out below, but not limited to the ways set out below.

In an embodiment, the controller 10 may be configured in use to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator 200 so that the hydrogen indication is maintained above a first predetermined value. The first predetermined value may be greater than zero. For example, the hydrogen indication may be an indication of the current drawn by the hydrogen generator 200 and the controller 10 may be configured in use to cause the voltage supplier 20 to maintain the current above a first predetermined value, such as, one Amp (1A). Further, the controller 10 may be configured in use to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator 200 so that the hydrogen indication is maintained below a second predetermined value, for example, three Amps (3A). Accordingly, the controller 10 may be configured in use to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator to keep the hydrogen indication within a predetermined range. In an embodiment, the predetermined range may be between two values both of which are greater than zero.

In an embodiment, the controller 10 may be configured in use to cause the voltage supplier 20 to vary the voltage supplied to the hydrogen generator by controlling the voltage supplied 20 to the hydrogen generator 200 according to a predetermined cycle. The controller 10 may be configured in use to vary a length of the predetermined cycle and/or a duty cycle of the predetermined cycle in dependence on the hydrogen indication. In an embodiment, the length may define a duration of a repeating interval of time, the interval being the predetermined cycle. In an embodiment, the duty cycle may define a portion of the predetermined cycle during which voltage is supplied to the hydrogen generator. For example, a duty cycle of 60% may indicate that voltage is supplied to the hydrogen generator for the first 60% of the predetermined cycle following which voltage is not supplied to the hydrogen generator for the remaining 40% of the predetermined cycle.

In an embodiment, the controller 10 may be configured in use to cause the voltage supplier 20 to increase the voltage supplied to the hydrogen generator 200 in dependence on the hydrogen indication. The controller 10 may be configured in use to cause the voltage supplier 20 to decrease the voltage supplied to the hydrogen generator 200 in dependence on the hydrogen indication.

Referring to Figure 2, there is shown a flow diagram of a method for controlling a hydrogen generator of a vehicle in accordance with an embodiment. The method may include receiving a hydrogen indication, wherein the hydrogen indication is a measure of a quantity of hydrogen being generated by the hydrogen generator. The method may also include varying a voltage supplied to the hydrogen generator in dependence on the hydrogen indication.

Referring to Figure 3, there is shown a control system 100' in accordance with an embodiment. The control system 100' may include a controller 10', a voltage supplier 20', and a current sensor 30. The voltage supplier 20' and the current sensor 30 may be in communication with the controller 10' such that each can exchange data with the controller 10'. The current sensor 30 may be configured in use to detect a current drawn by a hydrogen generator 200'. The current sensor 30 may be configured in use to generate a hydrogen indication from the detected current. The current sensor 30 may also be configured in use to provide the hydrogen indication to the controller 10'. The controller 10' may be configured to receive the hydrogen indication from the current sensor 30 and control the operation of the voltage supplier 20' in dependence on the received hydrogen indication. The voltage supplier 20' may be configured to receive a supply voltage from a battery 50 and convert the supply voltage into a converted voltage. The voltage supplier 20' may be configured in use to supply the converted voltage to the hydrogen generator 200'. The controller 10' may be configured in use to cause the voltage supplier 20' to vary the voltage supplied to the hydrogen generator 200' in dependence on the hydrogen indication received from the current sensor 30.

In an embodiment, the current drawn by the hydrogen generator 200' may be a current drawn by electrodes in a fluid (e.g. water) of the hydrogen generator 200'. For example, the fluid may be pure water. In an embodiment, potassium hydroxide (KOH) may be added to the pure water as an agent (e.g. an electrolyte and/or a catalyst). Additionally or alternatively, a metallic agent, such as Nickel, may also be added to the pure water to enhance conductivity. The control system 100' may be applicable to various different densities of agents in the fluid. The electrodes may be used to perform electrolytic separation of the fluid. The control system 100' may be applicable to various different types of electrode construction. For example, an electrode construction may be a set of plates separated by insulating gaskets. The set of plates may be made of stainless steel.

In an embodiment, the control system 100' may further comprise one or more shut-off sensors which may be in communication with the controller 10'. A shut-off sensor may be configured in use to monitor or measure a particular parameter, wherein the parameter may be such that when it reaches a certain value or condition the hydrogen generator 200' could be turned off, for example, to improve safety or efficiency. For example, the parameter may be a parameter of the hydrogen generator 200' (e.g. temperature, pressure, etc.); the vehicle (e.g. temperature, pressure, speed, etc.) and/or the environment (e.g. weather conditions, altitude, geographical location, etc.) The shut-off sensor may also be configured in use to provide the controller 10' with an indication of a value of the parameter being measured or monitored (i.e. a shut-off indication). The shut-off sensor may send the shut-off indication to the controller 10'. For example, the shut-off indication may be sent to the controller 10' at regular intervals, irregular intervals, or in dependence on the parameter value or a rate of change of the parameter value.

In an embodiment, exemplary shut-off sensors may include: a temperature sensor 60, a pressure sensor 70, a battery voltage sensor 90, and a current transducer 40.

In an embodiment, the temperature sensor 60 may be configured in use to detect a temperature of the hydrogen generator 200', generate from the detected temperature a temperature indication (i.e. a shut-off indication), and send the temperature indication to the controller 10'. The controller 10' may be configured in use to receive the temperature indication and analyze it to identify the temperature of the hydrogen generator 200'. Further, the controller 10' may be configured in use to cause the voltage supplier 20' to terminate the voltage supplied to the hydrogen generator 200' if the temperature indication indicates that the temperature of the hydrogen generator 200' is higher than a predetermined temperature threshold. In an embodiment, the threshold may be configurable by a user of the control system 100' and/or may be set to a default value. Therefore, the temperature sensor 60 may prevent the hydrogen generator 200' from overheating under a possible faulty condition. Advantageously, the hydrogen generator may be turned off before the risk of it exploding becomes too high.

In an embodiment, the pressure sensor 70 may be configured in use to detect a pressure of hydrogen in the hydrogen generator 200', generate from the detected pressure a pressure indication (i.e. a shut-off indication), and send the pressure indication to the controller 10'. The controller 10' may be configured in use to receive the pressure indication and analyze it to identify the pressure of hydrogen in the hydrogen generator 200'. Further, the controller 10' may be configured in use to cause the voltage supplier 20' to terminate the voltage supplied to the hydrogen generator 200' if the pressure indication indicates that the pressure of hydrogen in the hydrogen generator 200' is higher than a predetermined pressure threshold. In an embodiment, the threshold may be configurable by a user of the control system 100' and/or may be set to a default value. Therefore, the pressure sensor 70 may prevent pressure of the hydrogen in the hydrogen generator 200' from increasing too high under a possible faulty condition. Advantageously, the hydrogen generator 200' may be turned off before the risk of it exploding becomes too high. In an embodiment, the pressure sensor 70 may be configured to detect a pressure of the hydrogen and oxygen mixture in the hydrogen generator 200'. The pressure of the hydrogen and oxygen mixture may be used to monitor the current drawn by the hydrogen generator 200' under a normal working condition. For example, when the current drawn by the hydrogen generator 200' is 2 Amp (2A), the pressure of the hydrogen and oxygen mixture may be 0.2psi.

In an embodiment, the battery voltage sensor 90 may be configured in use to detect a charge level in a battery 50 in communication with the hydrogen generator 200', generate from the detected charge level a charge indication (i.e. a shut-off indication), and send the charge indication to the controller 10'. The controller 10' may be configured in use to receive the charge indication and analyze it to identify the charge in the battery 50. Further, the controller 10' may be configured in use to cause the voltage supplier 20' to terminate the voltage supplied to the hydrogen generator 200' if the charge indication indicates that the charge in the battery 50 is lower than a predetermined charge threshold. In an embodiment, the threshold may be configurable by a user of the control system and/or may be set to a default value. Therefore, the battery voltage sensor 90 may prevent the hydrogen generator 200' from running down the battery 50 under a possible faulty condition. Advantageously, the hydrogen generator may be turned off before the battery runs out of charge. Therefore, the battery voltage sensor 90 may prevent the hydrogen generator 200' from overstraining a weak battery.

In an embodiment, a motion sensor may be configured in use to detect motion of a vehicle, or an engine (not shown) of the vehicle, in which the control system 100' and the hydrogen generator 200' are installed. The motion sensor may be in communication with the hydrogen generator 200', generate from the detected motion a motion indication (i.e. a shut-off indication), and send the motion indication to the controller 10'. The controller 10' may be configured in use to receive the motion indication and analyze it to identify the level of motion, for example, the speed. Further, the controller 10' may be configured in use to cause the voltage supplier 20' to terminate the voltage supplied to the hydrogen generator 200' if the motion indication indicates that the motion is lower than a predetermined motion threshold, for example, slower than a certain speed. In an embodiment, the threshold may be configurable by a user of the control system and/or may be set to a default value. Therefore, the motion sensor may prevent the hydrogen generator 200' from needlessly generating hydrogen when the vehicle and/or engine are not moving.

In an embodiment, the motion sensor may be the current transducer 40. The current transducer 40 may be configured in use to convert motion of an engine (not shown) of the vehicle into a current signal. Accordingly, the current transducer 40 may be used to detect the level of motion of the engine, for example, in terms of the number of revolutions per minute, by determining the current of the current signal. The current transducer 40 may generate from the detected current a motion indication, and send the motion indication to the controller 10'. The controller 10' may be configured in use to receive the motion indication and analyze it to identify the level of motion. Further, the controller 10' may be configured in use to cause the voltage supplier 20' to terminate the voltage supplied to the hydrogen generator 200' if the motion indication indicates that the motion is lower than a predetermined motion threshold, i.e., slower than a certain speed. In an embodiment, the threshold may be configurable by a user of the control system and/or may be set to a default value. Therefore, the motion sensor may prevent the hydrogen generator 200' from needlessly generating hydrogen when the vehicle and/or engine are not moving.

In an embodiment, the current transducer 40 may be a transducer that provides a reading of the revolutions per minute (RPM) of a vehicle's engine (not shown). The RPM may represent a rotational speed of the vehicle's engine and thus a working level of the vehicle and/or the vehicle's engine. The current transducer 40 may be electrically isolated from a spark plug (not shown) of the vehicle and thus may not be intrusive to electrical circuits of the vehicle. For example, a cable of the spark plug may pass through an aperture of the current transducer 40 and a secondary electronic circuit of the current transducer 40 may be isolated from a high voltage terminal of the spark plug. The current transducer 40 may then be configured in use to detect the RPM of the engine by detecting the current measured. Accordingly, production of hydrogen may be a function of the vehicle's engine RPM.

In an embodiment, the motion sensor may comprise a motion detector which is coupled to the engine, for example, to detect engine motion such as revolution of the engine. Additionally or alternatively, the motion detector may be coupled to a moving part of the vehicle, such as, a wheel, a track, a roller or a propeller, and configured in use to detect motion of that moving part. In any case, the motion sensor may be configured in use to generate a motion indication corresponding to the detected motion for provision to the controller.

In an embodiment, the control system 100' may comprise a detector for determining if an engine of the vehicle in which the control system 100' and hydrogen generator 200' are installed is operational. Stated differently, the detector may be configured in use to detect whether or not the engine has started. For example, the detector may be linked to an ignition circuit of the vehicle and configured in use to determine when the engine has started based on the ignition circuit. The detector may be in communication with the controller 10' such that it can send an indication to the controller 10' that the engine has started or has stopped. Accordingly, the controller 10' may be configured in use to control the voltage supplier 20' not to provide voltage to the hydrogen generator 200' unless the engine is turned on, i.e. unless the engine is running.

In an embodiment, the control system 100' may further comprise one or more overdrive sensors which may be in communication with the controller 10'. An overdrive sensor may be configured in use to monitor or measure a particular parameter, wherein the parameter may be such that when it reaches a certain value or condition the voltage supplied to the hydrogen generator 200' could be varied, for example, to increase the rate of hydrogen generation, to increase the proportion of hydrogen in the fuel, and/or to improve vehicle performance. For example, the parameter may be a parameter of the vehicle (e.g. a load moved by the vehicle, a speed demand put on the vehicle's engine, a speed of the engine (e.g. in RPM), etc.) and/or the environment (e.g. a gradient of a slope on which the vehicle is travelling, — - etc.) The overdrive sensor may also be configured in use to provide the controller 10' with an indication of a value of the parameter being measured or monitored. The overdrive sensor may send the overdrive indication to the controller 10'. For example, the overdrive indication may be sent to the controller 10' at regular/irregular intervals, or in dependence on the parameter value or a rate of change of the parameter value. It is to be understood that in an embodiment, the controller may cause the voltage supplier to vary the voltage supplied to the hydrogen generator by increasing the length of time during which a voltage (e.g. a constant voltage) is supplied to the hydrogen generator. For example, the predetermined cycle length and/or the duty cycle could be increased. Additionally or alternatively, the controller may cause the voltage supplier to vary the voltage supplied to the hydrogen generator by increasing the value of the voltage supplied to the hydrogen generator.

In an embodiment, exemplary overdrive sensors include a slope detector 80 and a load detector (not shown).

In an embodiment, the slope detector 80 may be configured to detect the gradient of a slope on which the vehicle is moving, generate from the detection a slope indication (i.e. an overdrive indication), and send the slope indication to the controller 10'. The controller 10' may be configured in use to receive the slope indication and cause the voltage supplier 20' to vary the voltage supplied to the hydrogen generator 200', for example, to increase the rate of hydrogen generation, to increase the proportion of hydrogen in the fuel, if the slope indication indicates that the gradient of the slope is higher than a predetermined gradient threshold. In an embodiment, the threshold may be configurable by a user of the control system 100' and/or may be set to a default value. The slope detector 80 may be a MEM (micro electrical and mechanical) accelerator device for inclination detection of the vehicle. Advantageously, production of hydrogen by the hydrogen generator may be a function of the vehicle's angle of inclination. The slope detection may allow generation of hydrogen to meet the vehicle's increased consumption of energy or increased demand for energy when moving up a hill or ramp.

In an embodiment, the load detector may be configured to detect a mass of a load being moved by the vehicle. For example, the load detector may detect the mass of a trailer being towed by the vehicle, the mass of a roof box mounted on the roof of the vehicle, and/or the mass of the vehicle with its transportation load (e.g. people, luggage, fuel, etc.). The load detector may be configured in use to generate from the detected mass a load indication (i.e. an overdrive indication), and send the load indication to the controller 10'. The controller 10' may be configured to receive the load indication and cause the voltage supplier 20' to vary the voltage supplied to the hydrogen generator 200', for example, to increase the rate of hydrogen generation, to increase the proportion of hydrogen in the fuel, if the load indication indicates that the mass of the load is higher than a predetermined mass threshold. In an embodiment, the threshold may be configurable by a user of the control system and/or may be set to a default value.

Now referring to Figure 4A, the operation of a control system in accordance with an embodiment will be described in more detail.

In an embodiment, process flow begins at step 75, wherein the control system 100' checks a working level of the vehicle's engine, i.e. the control system 100' checks to see if the engine has started and is running, for example, using a detector as described above. In an embodiment, process flow may loop around step 75 until the control system 100' detects that the engine is running. Once the control system 100' detects that the engine is running, processing may flow to step 85.

In an embodiment, at step 85, the working level of the vehicle's engine may be detected by reading the vehicle's engine's RPM, for example, using the current transducer 40. At step 85, the control system 100' detects whether or not the RPM reading is greater than or equal to an upper threshold 'RPM _UPP ' (e.g.l500rpm). This check may enable the control system 100' to determine whether or not the vehicle is travelling at a sufficient speed for there to be a need to add hydrogen into the fuel. If the detected reading is greater than or equal to the upper threshold, processing flows to step 95 (described below), otherwise processing flows to step 140.

In an embodiment, at step 140, the control system 100' may detect whether or not the RPM reading is less than a lower threshold 'RPM _LTH ' (e.g.lOOOrpm). This check enables the control system 100' to determine whether or not the vehicle is travelling at a sufficient speed for there to be a need to add hydrogen into the fuel. If the detected reading is less than the lower threshold, processing flows to step 130, otherwise processing flows to step 95 (described below). In an embodiment, the upper threshold may be the same as the lower threshold.

In an embodiment, at step 130, when the detected reading is smaller than the lower threshold, the controller 10' may cause the voltage supplier to terminate the voltage supplied to the hydrogen generator 200', i.e. the controller 10' turns OFF the voltage supplied to the hydrogen generator V _out . Once the voltage has been terminated, processing may flow to step 85, which has described above.

In an embodiment, at step 95, the controller 10' may check the charge level in the battery 'Batt', for example, using the battery voltage sensor 90. If the battery charge is greater than or equal to a charge threshold 'Bnom' (e.g. 1 IV), processing may flow to step 115, otherwise processing may flow to step 130 which was described above.

In an embodiment, at step 115, the controller 10' may check the temperature of the hydrogen generator 'Temp', for example, using the temperature sensor 60. If the temperature of the hydrogen generator 200' is lower than a predetermined temperature threshold 'T _max ' (e.g. 65°C), processing may flow to step 125, otherwise processing may flow to step 130 which was described above.

In an embodiment, at step 125, the controller 10' may cause the voltage supplier 20' to supply voltage to the hydrogen generator 200'. Stated differently, the controller 10' may turn ON the voltage supplied V _out to the hydrogen generator 200'. This voltage supplied V _out to the hydrogen generator may be the supply voltage in the battery Vn (e.g. 12V). Following this operation, processing may flow to step 92.

In an embodiment, at step 92, the controller 10' may be configured to receive a slope indication, for example, from the slope detector 80. The slope indication may provide an indication of the gradient of the slope on which the vehicle is travelling. At step 92, if the gradient is less than a gradient threshold (e.g. 20 degrees from the horizontal), processing may flow to step 93, otherwise processing may flow to step 94. At step 93, the controller 10' may set a lower threshold I _LTH limit and an upper threshold I _upp limit of the current drawn by the hydrogen generator to define a first value range, for example, ILTH_N may be 1.5 A and I _upp _ _n may be 2 A. Alternatively, at step 94, when the vehicle is moving up a slope with a gradient more than the predetermined gradient threshold, the controller 10' may set the lower threshold I _L TH limit and the upper threshold I _upp limit of the current drawn by the hydrogen generator to a second value range, for example, ILTH_S may be 2 A and I _UPP _ _S may be 3 A. In an embodiment, the first value range may be lower than the second value range; however, the two value ranges may overlap. Once the above-described processing is complete, processing may flow to step 105 (Figure 4B).

Now referring Figures 4B, 4C, 4D, and 4E, there is shown a method for current regulation in accordance with an embodiment. Figure 4B illustrates the process flow of the method in accordance with an embodiment. Figures 4C, 4D and 4E show an exemplary circuit diagram (Figure 4C) of the control system 100' together with exemplary controller control waveforms (Figure 4D) and exemplary current response waveforms (Figure 4E).

In an embodiment, the controller 10' may be operable to cause the voltage supplier 20' to vary the voltage supplied to the hydrogen generator 200' in dependence on a hydrogen indication received by the controller 10' . The hydrogen indication may be an indication of a current (e.g. average current) drawn by the hydrogen generator. In an embodiment, the current drawn by the hydrogen generator 200' may be proportional to the hydrogen generated by the hydrogen generator 200'; therefore, the higher or lower the current drawn, the higher or lower, respectively, the quantity of hydrogen generated. Accordingly, the controller 10' may be operable to cause the voltage supplier 20' to vary the voltage supplied to the hydrogen generator 200' to maintain the current drawn by the hydrogen generator 200' within the value range set in either step 93 (first value range) or step 94 (second value range).

In an embodiment, the current drawn by the hydrogen generator may be an average current of multiple cycles. At step 105 (Figure 4B), the controller 10' may monitor the output current flow I _ou t drawn by the hydrogen generator 200' . At step 1 10, the controller 10' may determine if the output current flow I _out is greater than or equal to the preset lower threshold ILTH limit and, if so, processing flows to step 120 (described below), otherwise processing flows to step 1 12. Referring to Figures 4C and 4D, a waveform 220 may be generated by the controller 10' to control the voltage supplier 20' to perform a current regulation routine using a pulse width modulation technique. Figure 4C shows a circuit diagram of the control system 100' according to an embodiment. A pulse width modulation waveform 220 may be generated by the controller 10'. A control circuit of the control system may comprise a transistor, two resistors and a capacitor. The gate of the transistor may be connected to the controller in order to receive therefrom the pulse width modulation waveform 220. The drain of the transistor may be connected to the hydrogen generator. The hydrogen generator may also be connected to a supply voltage Vout 240 and draw a current lout 230. The source of the transistor may be connected to ground via one of the two resistors. Also, the source of the transistor may be connected to ground via a series combination of the other resistor and the capacitor. A current sensing signal may be taken from the series connection between the other resistor and the capacitor. The control circuit may be in communication with the hydrogen generator such that the waveform generated by the controller may be fed to the hydrogen generator 200'. The control circuit may be in communication with the current sensor 30 such that the controller can receive the detected current by the current sensor 30 and generate a waveform in dependence thereon.

In an embodiment the waveform may be a 10kHz frequency waveform, i.e the predetermined cycle length may be 0.1ms. The frequency of the waveform may be varied by the controller. Accordingly, the predetermined cycle of the voltage supplied to the hydrogen generator 200' may be varied by the controller 10'. When the pulse width of the pulse width modulation waveform 220 is at a maximum 250 (Figure 4D), an average current I _out 230 (Figure 4C) drawn by the hydrogen generator 200' may be higher (e.g. 3A) than the preset I _upp limit when the voltage V _out 240 (Figure 4C) is supplied to the hydrogen generator. In order to ensure I _ou t is within the preset value range between the preset I _upp limit and the preset I _LTH limit, the controller 10' may reduce the pulse width of the waveform 220 from the maximum 250 to a lesser pulse width 210. In this way, the controller 10' may operate to produce an average current lout (e.g. 2A) which is within the preset limits. According to the above described operation, a duty cycle of the waveform 220 may be adjusted by the controller 10' to vary the voltage supplied to the hydrogen generator 200' and maintain the current drawn by the hydrogen generator 200' within the predetermined thresholds and value ranges. Stated differently, referring to Figure 4E, in an embodiment, the voltage V _out to the hydrogen generator 200' may be turned ON at a time 305. The output current lout 340 may then increase to become higher (e.g. 4A) than the I _upp limit (e.g. 2A) at a time t ₂ 310. Therefore, the current regulation routine may turn OFF the voltage V _out at the time t ₂ 310 when the I _ou t is too high (e.g. 4 A). This operation may reduce I _ou t to zero. Furthermore, this cycle may be repeated from time t ₂ 310. Accordingly, the average current (e.g. 2 A) drawn by the hydrogen generator 200' may be maintained with the preset range and within the preset limits.

In an embodiment, after the voltage V _out is turned ON at time t ₃ 320, the output current may reach 3 A (350) at time 330. Accordingly, the current regulation cycle may be repeated to ensure that the average I _ou t is maintained within the I _upp limit (360) and ILTH limit (370).

Returning to Figure 4B, at step 110, the controller 10' may determine if the output current flow I _ou t is greater than or equal to the preset lower threshold ILTH limit and, if so, processing flows to step 120, otherwise processing flows to step 1 12.

At step 120, the controller 10' may determine if the output current flow I _out is less than or equal to the preset upper threshold I _upp limit and, if so, processing flows to step 75 which was described above, otherwise processing flows to step 122 (described below).

At step 1 12, when the output current flow I _out is lower than the lower threshold ILTH limit (e.g. 1.5 A), the controller 10' may generate a waveform with a higher duty cycle (i.e. increased pulse width or On' time) and consequently cause the voltage supplier 20' to increase the length of time per cycle during which the voltage is supplied to the hydrogen generator 200'. In an embodiment, only the length of time per cycle during which the voltage is supplied is changed, i.e. the value of the voltage supplied remains substantially constant. As a result, I _ou t may be increased. Further, at step 1 14, if the controller 10' determines that the duty cycle has reached to a maximum, i.e. the pulse width has reached the maximum 250, processing flows to step 1 16, otherwise processing flows to step 110 which was described above. . , , At step 116, the controller 10' may cause the voltage supplier to select a next higher voltage Vnxt! as the V _out for the hydrogen generator 200'. In an embodiment, the controller 10' may cause the voltage supplier 20' to convert a supply voltage from the battery 50 to increase the voltage of the converted voltage. Processing then flows to step 110 which was described above.

At step 120, when the output flow current I _ou t is higher than the upper threshold I _upp limit (e.g. 2A), processing flows to step 122. At step 122, the controller 10' may generate a waveform with a lower duty cycle (i.e. reduce the pulse width or On' time) and consequently cause the voltage supplier 20' to decrease the length of the time per cycle during which the voltage is supplied to the hydrogen generator 200'. In an embodiment, only the length of time per cycle during which the voltage is supplied is changed, i.e. the value of the voltage supplied remains substantially constant. Accordingly, the current drawn by the hydrogen generator 200' may be decreased to be lower than the preset upper threshold and within the preset value range. Processing may then flow to step 120 which was described above.

It is to be understood that in an embodiment, the controller may cause the voltage supplier to vary the voltage supplied to the hydrogen generator by varying (e.g. increasing or decreasing) the length of time during which a voltage (e.g. a constant voltage) is supplied to the hydrogen generator. This may be achieved by varying the length of the predetermined cycle and/or the duty cycle of the predetermined cycle. For example, voltage may be supplied using a duty cycle of 60% and a predetermined cycle of 100 micro-seconds. Additionally or alternatively, the controller may cause the voltage supplier to vary the voltage supplied to the hydrogen generator by varying (e.g. increasing or decreasing) the value of the voltage supplied to the hydrogen generator, for example, supplying a voltage of 8V, 10V or 12V.

The hydrogen generator may age over the course of its lifetime. For example, this may be caused as a conductivity of the fluid of the hydrogen generator decreases. As part of this aging process, the current I _ou t may gradually reduce for a constant voltage supply. For example, at the beginning of the hydrogen generator's life a supply voltage of 12V may cause a 2A current to be drawn by the hydrogen generator, whereas towards the end of the hydrogen generator's life a supply voltage of 12V may cause a 1A current to be drawn. Since the current drawn may be proportional to the flow rate of hydrogen generated, for a constant supply, the hydrogen generator may produce less hydrogen as it gets older.

In an embodiment, when I _out is lower than the I _LTH limit, the pulse width of the waveform generated by the controller 10' may be increased so as to enable I _out to fall within the preset limits again. As the hydrogen generator ages further, the maximum pulse width may still mean that I _ou t is lower than the I _LTH limit. In this case, the voltage Vout may be increased by the controller 10' causing the voltage supplier 20' to up-convert the voltage by a greater amount. Accordingly, the control system 100' may enable the efficient use of battery power.

An advantage of some embodiments is to enable the efficient use of the vehicle's battery by monitoring the current drawn by the hydrogen generator and varying the voltage supplied to the hydrogen generator. Also, an advantage of some embodiments is to enable the longer use of the vehicle's battery by terminating the voltage supplied to the hydrogen generator when the vehicle is not moving. Further, an advantage of some embodiments is to enable the longer working life of the vehicle's battery by preventing over-drain of vehicle's battery.

An advantage of some embodiments is to enable safe use of the hydrogen generator by monitoring the temperature thereof and the hydrogen pressure therein and by terminating the voltage supplied to the hydrogen generator when the temperature and/or hydrogen pressure are higher than predetermined thresholds. An advantage of some embodiments is to enable efficient use of the hydrogen generator by monitoring the current drawn by the hydrogen generator and varying the voltage supplied to the hydrogen generator, i.e. providing a suitable current flow through the hydrogen generator for generating a suitable amount of hydrogen in dependence on the vehicle's running state, such as, the rotational speed of the vehicle's internal combustion engine.

Although the control algorithm in Figures 4A-4E illustrates specific control parameters used in an embodiment, it is to be understood that this disclosure is not intended to be limiting. For instance, in some other embodiments, the parameters can be varied to provide different applications and versions of the control system for the hydrogen generator. As mentioned above, motion detection could be included to ensure that the vehicle is moving rather than only determining movement based on the vehicle's RPM. Additionally or alternatively, the vehicle's RPM could also be obtained by another method, such as, using the vehicle's alternator with an isolation transducer. In an embodiment, one or more sensors could be omitted, whilst one or more different sensors could be added.

Additionally, in an embodiment, calibration and delay in the algorithm may be performed. For example, one or more of the thresholds or ranges mentioned above could be set in dependence on a particular vehicle type or model, or a particular driver or driver profile. For example, the control algorithm could be calibrated to meet performance requirements or fuel efficiency requirements. Further, whilst certain aspects of the above-described operation are described in a sequential manner, it is to be understood that one or more of these aspects could be performed in parallel. For example, hydrogen generator temperature and hydrogen generator pressure could be determined at the same time.

The above-described embodiments have been described in combination, with an internal combustion engine. However, it is to be understood that in some other embodiments, the engine could be of a different type. For example, in some embodiments, the engine could be a gas-turbine engine or a steam engine.

It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to one or more of the above-described embodiments without departing from the spirit or scope of the invention as broadly described in the appended claims. The above-described embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.