BACKGROUND OF THE INVENTION A user of a vehicle can control the speed of the vehicle by adjusting a throttle position. In vehicles with an internal combustion engine, the throttle position determines the quantity of air-fuel mixture that enters into the combustion chamber. In electric vehicles, the throttle position determines the voltage or frequency applied to an electric motor. Conventionally, the throttle of a vehicle is adjusted by either rotating a throttle pipe or depressing an accelerator pedal. Throttle pipe is commonly found in the case of a two wheeler or a three wheeler and an accelerator pedal is commonly found in four wheelers.

In vehicles with an internal combustion engine, the fuel is allowed into the combustion chamber by means of a carburetor or a fuel injector. For vehicles with a carburetor, the throttle pipe or accelerator pedal is connected with a carburetor slider by means of a throttle cable. By rotating the throttle pipe or by depressing the accelerator pedal, the carburetor slider is displaced to increase/decrease the air - fuel mixture allowed into the combustion chamber. For vehicles with a fuel injector, the quantity of fuel injected into the combustion chamber is controlled by means of an Electronic Control Unit (ECU) that receives the throttle position signal. The throttle pipe or accelerator pedal is interfacing with a throttle position sensor that provides a signal indicative of the throttle position to the ECU. The rotation of throttle pipe or depression of accelerator pedal provides a signal to the ECU. Carburetor fitted vehicles also comprise an ECU and throttle position sensor for controlling the ignition timing or valve timing based on the throttle position.

The throttle pipe or accelerator pedal is maintained in tension such that a spring force acts to bring back a rotated throttle or a depressed accelerator pedal to its original position after the release of the external force applied by user. There is a considerable force required to rotate the throttle pipe or to depress the accelerator pedal in the conventional vehicle speed control system. During acceleration mode, the user has to continuously hold the throttle pipe in a rotated condition or the accelerator pedal in a depressed condition against the spring force in order to maintain this acceleration. During the vehicle cruising condition for long distances, the requirement of continuous force application by the user leads to pain in wrist or ankle, driver fatigue and discomfort. The continuous or periodic force applied wears out the throttle cable and other moving parts. This sort of disadvantage is reduced to nil in the present invention with no requirement of rotation of the throttle pipe.

FIELD OF THE INVENTION

The present invention relates to the speed control system in a vehicle by controlling the carburetor or fuel injector or Electric motor based on the throttle position with the help of the Electronic Control Unit (ECU). PRIOR ART DICUSSION

To control both acceleration and deceleration of vehicles having an electric drive with regenerative braking system, there is disclosed a control actuator which is biased to a neutral position, and which is controllably moveable between opposed positive and negative control positions. Signals ranging from a value corresponding to zero when in the neutral position to a positive or negative value are normally indicated depending on the amount of movement from the neutral position.

KR20097005690 entitled "An actuator assembly for controlling a fuel injection system of a large combustion engine" discloses an actuator assembly which includes an electric motor acting on a control shaft arranged to control the fuel injection and actuator control means provided with an electric power supply for controlling provided with back-up power in the form of capacitor power arranged to provided power for the actuator control means in case of loss of power or power failure of the electric power supply so as to enable the actuator control means to control the electric motor to drive the control shaft to a pre-defined safe position. US7915842 entitled "Actuator drive control device" describes an active vibration isolation support system includes an electronic control unit which supplies a target electric current to an actuator to periodically drive the actuator in an expansion and contraction manner with a target vibration waveform. The controller sets the target electric current by synthezing a driving primary electric current waveform corresponding to the target vibration waveform for the actuator with higher-order electric current waveforms which eliminate higher-order vibration components of the actuator corresponding to the driving primary electric current waveform. In other prior art, there is a disclosure of the speed control system by a third party, which uses data relating to geography and operator. In some instances, it is desirable to limit the power generated by an engine of a vehicle, to limit the maximum speed of the engine or to have a cruise control function on the vehicle for example. An electronic control unit may be fitted to an engine, whilst a throttle valve is controlled by an operator/driver of a vehicle; this leaves the ECU operable to control the ignition and, where available, the injection, in order to control or adjust the power of the engine. For example, when the engine reaches a predetermined maximum speed, the ECU will control the engine such that same of the spark plugs are not fired and/or that fuel is not injected in every combustion chamber.

- SUMMARY It is the primary object of the invention to provide an Electronic Control Unit to control the speed of the vehicle by controlling the carburetor or fuel injector or Electric motor based on the throttle position sensor signal. There is no requirement for the throttle pipe to be rotated or the accelerator pedal to be depressed in order to adjust the throttle position as in conventional method.

The application of a force on the throttle pipe for a short duration in a first predetermined direction will change the throttle position to an accelerating mode. The application of a force on the throttle pipe for a short duration in a second predetermined direction will change the throttle position to a decelerating mode. In case of a four wheeler, application of force on the accelerator pedal for short duration in one direction causes acceleration of vehicle and removal of force causes deceleration. A throttle position sensor identifies the application of force and provides a suitable signal to an Electronic Control Unit (ECU). The ECU controls the carburetor or fuel injector or Electric Motor based on the throttle position sensor signal and thereby controls the vehicle speed. Thus the wear and tear of moving parts like throttle pipe, throttle cable and accelerator pedal are significantly reduced and cases of rider wrist pain, fatigue and discomfort are alleviated.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 illustrates the position of the throttle pipe and its accompanying parts in a two wheeler.

Figure 2 illustrates the position of a an accelerator pedal in a four wheeler. Figure 3 illustrates the position of the throttle position sensor with its signal to ECU.

Figure 4 illustrates a block diagram representing a speed control system for vehicle with an Internal Combustion Engine wherein throttle position sensor produces a signal indicative of the application of force on a throttle pipe.

Figure 5 illustrates a block diagram representing a speed control system for a vehicle with an electric motor wherein an Electric Control Unit processes the signal from the throttle position sensor. 1 000524

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 illustrates the position of the throttle pipe 3 which will be connected with the throttle cables 1, both are fixed to the handle bar of the vehicle. The other accompanying parts in the figure are UP mark 1, master cylinder 2, retainer ring 7, pinch bolt 6, holder 8, screws 5 and application of oil 10 and grease 9 respectively.

A throttle pipe is fixed to a handle bar of a vehicle. The throttle pipe movement with respect to the handle bar is less than a predetermined small angle. A user of the vehicle can apply a torque in a clockwise or anticlockwise direction on the handle bar. A throttle position sensor is in contact with the throttle pipe. Whenever a torque is applied on the throttle pipe, a signal indicative of the magnitude and direction of the torque is generated by the throttle position sensor. The throttle position sensor is connected with a power supply in the vehicle for generating the signal indicative of applied torque. Figure 2 illustrates the position of the accelerator pedal in a four wheeler with its accompanying parts.

In a first embodiment (shown in Figure 3), the throttle position sensor is connected with an Engine Control Unit (ECU) of the vehicle comprising an internal combustion engine. The ECU processes the throttle position signal generated by the throttle position sensor to recognize the magnitude and direction of the applied torque. Referring Figure 4, the ECU 103 processes the throttle position signal generated by the throttle position sensor

102 to recognize the magnitude and direction of the applied torque. Whenever the ECU

103 recognizes a non-zero magnitude of applied torque, for a predetermined short duration, the ECU 103 provides suitable signal to an actuator 104 that is connected with a carburetor 105 of the internal combustion engine 106. The actuator 104 moves a slider to increase or decrease the air-fuel ratio and thereby accelerate or decelerate the vehicle to a new speed level. The magnitude and direction of the applied torque determines the direction and displacement of slider movement. The rate of torque application on the throttle pipe 101 will determine the velocity of the carburetor slider and thereby the vehicle acceleration. When the throttle pipe 101 is subjected to a torque in an accelerating direction, for a predetermined short duration, for instance anti-clockwise torque application, the throttle position sensor provides an accelerate signal to the ECU. The ECU provides suitable signal to the actuator 104 to move the slider of the carburetor 105 by a predetermined displacement proportional to the magnitude of applied torque to enrich fuel content in the air-fuel mixture allowed in to the combustion chamber. The ECU will control the actuator such that the carburetor slider maintains the new high speed position although the throttle pipe is not continuously held in a rotated position. Thus the vehicle will continue to travel at the new high speed without continuous rotation of throttle pipe and without continuous torque application. In order to decelerate the vehicle, a torque applied in the decelerating direction for a short duration, for instance in clockwise direction, will cause a decelerate signal to be generated by the throttle position sensor. The ECU in turn will provide suitable decelerate signal to the actuator and thereby cause displacement, in proportion to the magnitude of deceleration torque applied, of the carburetor slider in a decelerating direction to deplete fuel content in air - fuel mixture. The ECU will continue to provide decelerate signal to the actuator although the torque application in clockwise direction has been discontinued. The vehicle speed will thus reduce to a low speed.

The actuation of the carburetor slider is controlled by the ECU and in addition to the throttle position sensor signal, the ECU can also process other sensor signals like engine temperature signal, inlet manifold pressure signal and exhaust gas sensor in order to maintain efficient, safe and reliable operation of the engine and vehicle. The user can thus accelerate or decelerate the vehicle by merely applying a torque beyond a predetermined threshold level in the predetermined accelerating or decelerating direction for at least a predetermined duration. The magnitude of increase / decrease in vehicle speed will be proportional to the magnitude of the torque applied to the throttle pipe.

When the magnitude of the torque applied is increased, the corresponding actuation signal provided to the actuator by the ECU is also increased to move the slider by a proportional large displacement and thereby accelerate the vehicle to a greater speed.

In a second embodiment (shown in Figure 5), an Electronic Control Unit (ECU) 203 controls an electric motor 204 based on the throttle position sensor signal. When a torque is applied in the accelerating direction, for at least a predetermined duration, the ECU 203 provides suitable signal to the electric motor 204 in order to accelerate the electric motor to a new high speed level. The ECU controls the electric motor to rotate at the new high speed even after discontinuation of the accelerating torque. The electric motor speed could be controlled by several techniques like variable frequency control, variable voltage control, V-f control (voltage frequency control)etc. When a torque is applied in the decelerating direction, the ECU recognizes that the user desires to reduce the speed of the vehicle and hence controls the electric motor speed to reach a new low speed.

The acceleration, rate of change of vehicle speed, can also be controlled by the ECU by recognizing the rate of change of torque applied to the throttle pipe or accelerator pedal. In a vehicle with the internal combustion engine, the rate of carburetor slider movement is determined by the rate of torque application to the throttle pipe or force application to the accelerator pedal. In a third embodiment, the throttle position sensor generates a signal only when a torque is applied on the throttle pipe in accelerating direction or a force is applied on accelerator pedal in accelerating direction. Application of torque or force in deceleration direction does not generate any signal from the throttle position sensor.

Whenever a torque is applied on the throttle pipe in an accelerating direction, the throttle position sensor generates an acceleration signal which is recognized by the ECU. The ECU provides an accelerate signal to an actuator for moving a carburetor slider or to a fuel injector solenoid or to an electric motor and thereby accelerates the vehicle. If the torque applied On the throttle pipe is released, the throttle position sensor ceases to generate acceleration signal and the ECU recognizes that the user wants to decelerate the vehicle and hence provides appropriate signal to the actuator or motor in order to decelerate the vehicle. The deceleration depends on the rate at which torque applied to the throttle pipe was released.

This embodiment requires continuous application of torque or force on the throttle pipe or accelerator pedal respectively in order to drive the vehicle at constant speed. But there is no rotation of throttle pipe or depression of accelerator pedal required in order to accelerate or decelerate the vehicle. This embodiment is beneficial in vehicles with accelerator pedal wherein it is difficult to apply force in decelerating direction i.e. upward direction. The deceleration of vehicle on release of the torque applied on throttle pipe continues until a predetermined idling speed of engine is reached in case of vehicles with internal combustion engine and until a zero applied torque on electric motor is reached in vehicles with an electric motor.

In addition to the above mentioned embodiments, which are applicable to two wheelers and three wheelers, the throttle position sensor could also generate signal based on the direction and magnitude of force applied on accelerator pedal in four wheelers. The user need not continuously depress the accelerator pedal in order to accelerate the vehicle. The application of force for at least a small predetermined duration in an accelerating direction is sufficient to accelerate the vehicle to a higher speed. The process can be continued to accelerate the vehicle further, if necessary. The throttle pipe or accelerator pedal is separate parts that rotate/move by a small angle/small distance during torque application due to the inherent material properties of the throttle position sensor. But the angle of movement or depression is very less when compared to the existing design.

Thus the wear and tear of moving parts like throttle pipe, throttle cable and accelerator pedal are significantly reduced and cases of rider wrist pain, ankle pain, fatigue and discomfort are alleviated.