BACKGROUND

[0001] Conventional fuel control for fuel cells relies on mechanical valves that are physically governed. These conventional valves use a dome-loaded mechanical regulator. The regulator senses the desired downstream pressure on one side of the dome with respect to a reference pressure, which in some cases is either ambient air pressure or another pressure in the fuel cell system. The conventional reference pressure may be the cathode air pressure, physically connected to the mechanical regulator though a tube so that the reference pressure itself pushes on the dome of the mechanical regulator. With the use of springs acting for and against the dome, the dome moves a pintle that opens and closes an orifice in the regulator, thereby allowing more or less flow of gaseous hydrogen fuel to enter the engine. By adjusting the spring constants, or length, mechanical adjustments define a fixed downstream pressure relative to the reference pressure. No further adjustment can be made to the pressure during runtime of a fuel cell hosting such a mechanically-governed fuel valve. Moreover, it is very expensive and time consuming to redesign and source changes to the conventional mechanical regulator, springs, and adjustments for any particular application or engine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The detailed description is set forth with reference to the accompanying figures. The use of the same reference numbers in different figures indicates similar or identical items or features.

[0003] Fig. 1 is a diagram of an example fuel cell electric vehicle hosting a fuel cell engine that includes an electronically controlled fuel valve. [0004] Fig. 2 is a block diagram of a fuel cell engine that includes an electronically controlled fuel valve and an electronic controller.

[0005] Fig. 3 is a flow diagram of an example electronic control process for governing an electronically controlled fuel valve.

[0006] Fig. 4 is a block diagram of an example electronic controller for governing an electronically controlled fuel valve of a fuel cell engine.

[0007] Fig. 5 is a flow diagram of an example method of electronically controlling a fuel valve of a fuel cell.

[0008] Fig. 6 is a flow diagram of an example method of making a fuel cell engine including an electronically controlled fuel valve.

DETAILED DESCRIPTION

[0009] This disclosure describes advanced fuel control for fuel cells. In an implementation, a fuel cell engine has one or more fuel valves, each with a variable orifice under electronic control. The size of the orifice is adjusted in real time to provide instantaneous fuel pressure changes at the cell stack. Providing electronic control of fuel pressure and fuel flow enables a fuel cell or fuel cell engine to adjust to conditions without the need for mechanical tuning. Electronic solenoids or other electronic actuators adjust the orifice of the fuel valve, thereby controlling fuel pressure. Predictive electronic control of fuel pressure enables fast startup of a fuel cell by increasing the pressure during startup, preemptive fuel pressure control for dynamic response to load changes, and diagnostics by removing fuel pressure to detect and troubleshoot issues with the fuel cell. The advanced fuel control described herein also reduces parts count and complexity of a fuel cell engine, reducing cost. [0010] In an implementation, an electronic controller of an example fuel cell engine has memory access to preprogrammed pressure setpoints in a truth table for each operational state of a fuel cell vehicle. The electronic controller monitors multiple pressures in the fuel cell engine in relation to the setpoints to devise fuel valve control. For instantaneous responsiveness in the vehicle or other machine, the setpoints are updated in real time in one or more circuits that include a PID control loop governing the orifice of a respective electronic fuel valve. The electronic controller and electronic fuel valves described herein provide rheostat-like responsiveness in a machine or vehicle, even though the cell stack of the fuel cell engine relies on a gaseous fuel that is subject to (non-electronic) physical transport between the fuel supply and the anodes of the cell stack.

Example Systems

[0011] Fig. 1 shows an example fuel cell engine 100 in a fuel cell electric vehicle (FCEV) 102, referred to herein as “vehicle 102.” The example vehicle 102 is representative of a machine hosting the fuel cell engine 100, but numerous types of other machines may host the fuel cell engine 100, or the fuel cell engine 100 may be a standalone device. The example fuel cell engine 100 generates electric power for the vehicle 102 or machine but is not a mechanical engine that produces rotational torque, for example. Hence, the example vehicle 102 in Fig. 1 also has an electric motor 104 for propulsion.

[0012] The electric motor 104 converts electricity from the fuel cell engine 100 and from high-voltage batteries 106 into motion. The fuel cell engine 100 powers the electric motor 104 through a power distribution unit 110, and also charges the high-voltage batteries 106. The high-voltage batteries 106 may assist in powering the electric motor 104, complementing the fuel cell engine 100 through the power distribution unit 110. The high- voltage batteries 106 may also reclaim energy generated from braking as electrical energy, in addition to storing power from the fuel cell engine 100. The power distribution unit 110 directs various high-voltage electric currents between the fuel cell engine 100, high-voltage batteries 106, power distribution unit 110, and electric motor 104 along a high-voltage power bus 112.

[0013] The example vehicle 102 has a high-pressure supply of hydrogen gas 108 used as fuel at the cell stack 114 of the fuel cell engine 100 to produce electric power. The hydrogen gas 108 is provided to the cell stack 114 though an electronically controlled fuel valve 116, governed by an electronic controller 118 onboard the fuel cell engine 100. The electronic controller 118 of the fuel cell engine 100 may be in communication with a more general electronic control unit (ECU) 120 of the vehicle 102 and is to be differentiated from the ECU 120 of the vehicle 102. The ECU 120 of the vehicle may also be called the “engine control unit,” “electronic control module,” or “onboard computer” of the vehicle 102. The vehicle’s ECU 120 tracks and controls conventional functions of the vehicle 102, such as speed, acceleration, braking, signaling, electric motor functioning, shifting, heating and cooling, and accessories of the vehicle 102. The electronic controller 118 of the fuel cell engine 100, on the other hand, controls the power production and functioning of the fuel cell engine 100 via systems and components that are usually onboard and contained within the fuel cell engine 100.

[0014] The layout of components in the example vehicle 102 of Fig. 1 is only one example configuration. The various components of the example vehicle 102 may be arranged in numerous different layouts and may have many more incidental components not shown in Fig. 1. For example, the vehicle 102 may have a low voltage battery (e.g., 12 volts) to power conventional automotive devices and accessories. The low voltage battery (not shown) may be charged by a DC/DC step down transformer of a power conditioning system (not shown) of the fuel cell engine 100 and/or from the high-voltage batteries 106. The supply of high- pressure hydrogen gas 108 (gas tank) may have a filler port on the outside of the vehicle 102 to replenish the supply of hydrogen gas 108.

[0015] Each of the major components shown in Fig. 1 may have numerous subcomponents. For example, the fuel cell engine 100 has its own inherent electrical system and its own electronics, including one or more DC/DC converters of a power conditioning system. The DC/DC converters modify the voltage and current of the electric power generated for transmission onto the high-voltage power bus 112: for the power distribution unit 110, the electric motor 104, and the high-voltage batteries 106. The DC/DC converter(s) of the fuel cell engine 100, which step-up low voltage electrical output from the cell stack 114 of the fuel cell engine 100, are to be differentiated from the power distribution unit 110 of the vehicle 102, which directs high-voltage and high-current electrical flows between major components of the vehicle 102 (including the fuel cell engine 100) via the high-voltage power bus 112. Thus, the power distribution unit 110 of the vehicle 102 is in communication with a high-voltage side of the DC/DC converters of the fuel cell engine 100.

[0016] Fig. 2 shows the example fuel cell engine 100 in greater detail. The fuel cell engine 100 has multiple systems, but not all systems are shown in Fig. 1. For example, a power conditioning system of the fuel cell engine 100 containing DC/DC transformers, regulators, and so forth, is not shown in Fig. 2. The example fuel cell engine 100 may also have a cooling system, including a water circulator and cooling plates among the heatproducing anodes 202 and cathodes 204. In routine operation, the fuel cell engine 100 produces heat, which usually must be heat-sinked and proactively cooled to prevent destructive heat damage to components of the fuel cell engine 100 during operation.

[0017] Each electrochemical cell of the cell stack 114 has an anode 202 and a cathode 204 on either side of an intervening electrolyte, such as a polymer electrolyte membrane (PEM), for example. “Anode” and “anodes” is used interchangeably herein, although Fig. 2 shows a single anode 202 as an example, the cell stack 114 contains numerous anodes 202.

Likewise, “cathode” and “cathodes” is used interchangeably. Instances of the PEM (electrolyte) between each anode 202 and cathode 204 are not shown in Fig. 2.

[0018] A fuel processing system 208 provides the hydrogen gas 108 fuel to the cell stack 114 and has an electronically controlled fuel valve 116. The fuel processing system 208 may have other valves capable of assuming various valve configurations and may have additional instances of the electronically controlled fuel valve 116 and other electronically controlled non-fuel valves, depending on implementation.

[0019] In an implementation, the fuel processing system 208 has one or more ejectors 210, 212 that flow gaseous hydrogen 108 to the anode 202. Each ejector 210, 212 also creates a vacuum and suction through a return line 214 to draw and recycle unreacted hydrogen gas 108 from the anode exhaust 216 back to the respective ejector 210, 212. One or more overdrive valves 218 may be opened to bring each additional ejector 212 into the fuel supply circuit, when more power is needed from the fuel cell engine 100 than a single ejector 210 can provide. The fuel processing system 208 has additional components, such as an initial filter 220 for the incoming hydrogen gas 108, and an on-off valve 222 that closes off gas flow coming into the electronically controlled fuel valve 116. A check valve 224 at the output of each additional ejector 212 prevents fuel backflow through each additional ejector 212 and the return line 214.

[0020] An air processing system 226 of the fuel cell engine 100 provides oxygen to the cell stack 114 through a blower 228, turbocharger, or compressor for injecting air into the cell stack 114. A recycle valve 230 may be opened to create suction at the cathode exit 232 through an air return line 234 to the blower 228 in order to deplete the cathode air of oxygen or in failure cases where pressures in the cathode are too extreme. The air processing system 226 has an air filter 236 for incoming air and may have other ancillary components. [0021] An exhaust system 238 of the fuel cell engine 100 provides an exit for gases from the fuel cell engine 100 and may determine the disposition of a water vapor end product of the cell stack 114 during operation. Some exhaust systems 238 may include mechanisms for handling or burning any hydrogen gas 108 still present in the exhaust flow. An exhaust valve 240 is opened to allow gases to exit but may also provide backpressure and may be closed for other states and functions of the fuel cell engine 100.

[0022] The example fuel cell engine 100 has multiple sensors installed in numerous locations in the fuel processing system 208, the air processing system 226, the exhaust system 238, and the cooling system (not shown in Fig. 2). Each sensor may also have a transmitter as needed for sending data to the electronic controller 118. For example, an input pressure sensor 242 and an input temperature sensor 244 determine physical characteristics of the hydrogen gas 108 at the entrance to the initial on-off valve 222. A post-fuel-valve pressure sensor 246 intervenes downstream from the electronically controlled fuel valve 116, but before the main ejector 210 at this location, because the electronically controlled fuel valve 116 has the purpose of changing fuel flow and pressure there. A pre-anode pressure sensor 248 determines the fuel pressure at the output of the one or more ejectors 210, 212 and provides a key pressure measurement quantifying the fuel available at surfaces of the anodes 202. The fuel is intended to be in a stoichiometrically correct ratio with the oxygen at the cathodes 204, or in slight excess, for purposes of the electrochemical reaction in the cell stack 114 that will produce electric power from the fuel and oxygen. The fuel processing system 208 may have more sensors than shown in Fig. 2, including flow and temperature sensors of the cooling system, which also relates to the fuel processing system 208.

[0023] The air processing system 226 may have an input pressure sensor 250 relative to the cathode 204, between the blower 228 and the cathode 204. An output pressure sensor 252 relative to the cathode 204 intervenes at the cathode output 232, between the cathode 204 and the exhaust valve 240. The output pressure sensor 252 may also be regarded as an output pressure sensor 252 for the anode 202 too, when the anode output 216 and cathode output 232 join in a common “wye” junction before the exhaust valve 240.

[0024] The electronic controller 118 of the fuel cell engine 100 manages and supervises all the operations of the fuel cell engine 100 during routine operation. In an implementation, the electronic controller 118 has a communication channel, data link, a direct electrical connection, or an indirect electrical connection to every component in the fuel cell engine 100 that involves electricity, including the cell stack 114. In an implementation, the electronic controller 118 and vehicle 102 may use a communicative vehicle bus, such as a Controller Area Network (CAN) defined by SAE J1939 and/or a Local Interconnect Network (LIN) or other communication channels.

[0025] In an implementation, the electronic controller 118 governs one or more instances of the electronically controlled fuel valve 116 with no conventional extra tubes or passages to affect the electronically controlled fuel valve 116. Control of the fuel valve 116 is purely electronic, managed by the electronic controller 118 and sensors located throughout the fuel cell engine 100 that are in communication with the electronic controller 118.

[0026] During routine operation of the fuel cell engine 100, the fuel processing system 208 supplies the hydrogen gas 108 to the anodes 202 of the cell stack 114 at pressures calculated by the electronic controller 118. The fuel processing system 208 controls the pressure of the hydrogen gas 108 at the anodes 202 in real time along a continuum of possible pressure values, based on the current state and power requirements of the vehicle 102 or other machine.

[0027] The pressure of the hydrogen gas 108 at the anodes 202 is precision-controlled by the electronically controlled fuel valve 116 and electronic controller 118 in real time. The electronically controlled fuel valve 116 has a variable orifice that is fully adjustable to any opening size between fully open and fully closed via the electronic control. The electronically controlled fuel valve 116 and the opening size of its orifice may be electrically actuated by a solenoid, servo, linear actuator, rotary actuator, and so forth. In an example implementation, a small electric motor drives a train of reduction gears with a potentiometer connected to the mechanical output shaft, for example. Electronics provide a closed-loop servomechanism for variably actuating the electronically controlled fuel valve 116 to any size opening along the continuum, from fully open to fully closed. In another implementation, a linear actuator moved by the magnetic flux generated by an electronic solenoid is used to control the orifice size of the electronically controlled fuel valve 116 in real time. Other mechanisms may be used to electronically control the orifice size of the electronically controlled fuel valve 116 within the continuum of variable openness.

Electronic Fuel Control

[0028] The electronically controlled fuel valve 116 is under dynamic control of the electronic controller 118 based on several sources of information, including feedback from one or more pressure sensors 242, 246, 248, 250, 252, for example. The electronic controller 118 monitors, analyzes, and decides a current orifice size of the electronically controlled fuel valve 116 in the context of current power requirements of the vehicle 102 or other machine, various states of the vehicle 102, temperature information from the cooling system, and several other factors to be described below. The electronic controller 118 may employ advanced logic and decision-making taking into account stored data and pressure readings across multiple sensors in the fuel cell engine 100 when controlling fuel pressure and fuel flow through the electronically controlled fuel valve 116 in real time.

[0029] In an example system, the electronic controller 118 may execute a logic process at regular intervals that includes: monitoring multiple different pressures of the fuel cell engine 100 via a selected combination of the available pressure sensors 242, 246, 248, 250,

252; calculating a current pressure setpoint for the fuel pressure at the anode 202, wherein the current pressure setpoint is calculated from the selected combination of the multiple pressures; and controlling the orifice size of the electronically controlled fuel valve 116 valve via a PI or PID control loop based on the current pressure setpoint calculated for the current time interval. The operational logic of the electronic controller 118 may be implemented purely in hardware, such as CMOS digital circuitry, one or more application-specific integrated circuits (ASICs) or even total-transistor-logic, or other hardware elements.

[0030] Fig. 3 shows an example electronic control process 300 (“cycle 300”) implemented by the electronic controller 118 for governing the electronically controlled fuel valve 116 in real time. In the flow diagram of Fig. 3, operations are shown in discrete visual blocks. At block 302, an individual cycle 300 of the electronic control process 300 begins. In an implementation, the entire execution time of one cycle is 1 millisecond (ms). Thus, the scan rate for repeating the cycle 300 at regular intervals can be once or several times per second, tens of times per second, or even hundreds of times per second.

[0031] In an implementation, the cycle start 302 includes polling or receiving input from the vehicle 102 hosting the fuel cell engine 100. The electronic controller 118 may include electronics for communicating with sensors in the vehicle and deciding a state of the vehicle (such as starting up, accelerating, decelerating, shutting down, off, and so forth). Alternatively, the electronic controller 118 may include electronics for simply receiving the current state of the vehicle 102 from the ECU 120, from an engine control module, or from another onboard computer of the vehicle 102 as a message or as data.

[0032] At block 304, the electronic controller 118 queries a truth table 306 (lookup table, binary decision tree, etc.) onboard the fuel cell engine 100 using the current state of the vehicle 102 as the query. The truth table 306 is accessed to retrieve a set of stored pressure data 308 associated with the current state of the vehicle 102 used for executing the current cycle of the electronic control process 300. Alternatively, the electronic controller 118 may query the truth table 306 with sensor data directly, in which case the truth table 306 is outfitted to return both a current state of the vehicle 102 and the stored pressure data 308 for that current state of the vehicle 102, for the current cycle of the electronic control process 300.

[0033] The stored pressure data 308 may include a startup pressure setpoint, a shutdown pressure setpoint, a minimum pressure setpoint, a first pressure increment value for a first pressure measured at the cathode air input, a second pressure increment value for a second pressure measured at the cathode exhaust, a capacity pressure setpoint, and a step change factor, for example. These data will be described further below.

[0034] At block 310, the electronic control process 300 decides whether the current state of the vehicle 102 is startup or not. If the current state of the vehicle 102 is startup, then a startup pressure setpoint 312 from the stored pressure data 308 is forwarded as a first input 314 for a PI or PID control loop 316 or controller (hereinafter “PID control loop 316”). The PID control loop 316 is the interface between the electronic controller 118 (and electronic control process 300) and the electronically controlled fuel valve 116. The first input 314 is the dynamic fuel pressure setpoint for the logic of the PID control loop 316. A measured value of fuel pressure at pressure sensor 248 (see Fig. 2), which is the fuel pressure at the active surfaces of the anode 202, is the second input 318 for the PID control loop 316 and provides a process variable for the PID control loop 316. The PID control loop 316 makes reference to the current pressure measured at pressure sensor 248 during the current cycle of the electronic control process 300. The PID control loop 316 compares this pressure 248 with the pressure setpoint of the first input 314, and determines the difference, or error, between the first input 314 and second input 318. The PID control loop 316 “steers” the orifice of the electronically controlled fuel valve 116 by either opening or closing the orifice in proportion to the magnitude and direction of the difference, in order to adjust the fuel pressure (as measured at pressure sensor 248) up or down, and back to the setpoint that is provided to the PID control loop 316 as the first input 314.

[0035] The PID control loop 316 may have a scan rate that matches the scan rate of the entire electronic control process 300, especially if the electronic control process 300 cycles many times per second. Alternatively, the PID control loop 316 may have its own independent scan rate that includes executing PID calculations and adjusting the orifice of the electronically controlled fuel valve 116 at the scan rate using the current first input 314 and second input 318 at hand. For example, the entire electronic control process 300 may cycle 1 time per second, while the PID control loop 316 cycles 1-20 times per second. The PID control loop 316 and its first input 314 and second input 318 may be considered the duty cycle control of the electronically controlled fuel valve 116.

[0036] In the electronic control process 300, if the state of the vehicle 102 at block 310 is not startup, then the electronic control process 300 tests whether or not the current state of the vehicle 102 is shutdown at block 320. If the current state of the vehicle 102 is shutdown, then a shutdown pressure setpoint 322 from the stored pressure data 308 is forwarded as the operative setpoint for the first input 314 of the PID control loop 316.

[0037] In the example electronic control process 300 shown in Fig. 3, if the current state of the vehicle 102 is neither startup 312 nor shutdown 320, then the electronic control process 300 employs additional logic to calculate a dynamic pressure setpoint to be used as the first input 314 of the PID control loop 316.

[0038] In one example embodiment of constructive setpoint logic, the electronic controller 118 considers the combination of pressures at the entrance of the cathodes 204, measured by pressure sensor 250, and at the exhaust output 232 of the cathodes 204, measured by pressure sensor 252. At block 324, the pressure monitored at pressure sensor 250 is input into a first adder 326. This pressure value represents the air pressure at the entrance to the cathode 204. In this example, it is important to maintain anode pressure above cathode pressure for failure mode reasons and proper operational performance. The adder 326 increments this pressure value by first pressure increment value 328 from the set of pressure data 308 obtained from the truth table 306. This incrementing tells the PID control loop 316 to maintain a fuel pressure at the anode 202 that is slightly higher than the air pressure at the cathode 204. Therefore the fuel pressure follows the air pressure in the logic of this electronic control process 300. The air pressure, controlled by the blower 228, is controlled by the electrical current generated by the cell stack, which follows the electrical load applied to the fuel cell engine 100 by the vehicle 102. However, the example electronic control process 300 of Fig. 3 does not necessarily use the single value from pressure sensor 250 as the setpoint value for the first input 314 for the PID control loop 316, even though the pressure read from sensor 250 has been slightly incremented.

[0039] At block 330, the electronic control process 300 also monitors an air pressure at the cathode exit 232 using pressure sensor 252. The electronic control process 300 increments this pressure reading 252 by a second pressure increment value 332 from the pressure data 308 obtained from the truth table 306, or calculated. The two air pressures processed at adders 326, 334 represent the air pressure difference across the cathodes 204 of the cell stack 114, which in combination is a reading of the amount of oxygen being consumed during power production in the cell stack 114. This pressure change derived from the combination of pressures provides more sophisticated information for electronically controlling fuel pressure via the electronically controlled fuel valve 116, than just a single air pressure reading alone. [0040] A comparator 336 compares the output of the first adder 326 and the second adder 334 with each other and with a minimum pressure setpoint 338 from the pressure data

308 obtained from the truth table 306 for the current state of the vehicle 102. In an implementation, the comparator 336 selects the maximum value from these three candidate values, to pass forward as the current dynamic fuel pressure setpoint and the first input 314 for the PID control loop 316.

[0041] At block 340, the electronic controller 118 may open an additional ejector 212 of the fuel processing system 208 when the dynamic fuel pressure setpoint and first input 314 for the PID control loop 316 exceeds a capacity pressure setpoint 342 in the pressure setpoint data 308 obtained from the truth table 306, or calculated by the electronic control process 300, depending on implementation. When an additional ejector 212 has been opened to increase the fuel flow to the anodes 202, a step change factor 344 in the pressure setpoint data 308 obtained from the truth table 306 is fed forward to the PID control loop 316 to increase the fuel pressure by the step change factor 344. The PID control loop 316 of the electronic controller 118 scales the output of the PID control loop 316 to account for increased fuel flow through the additional ejector 212, thereby also stepping up the orifice size of the electronically controlled fuel valve 116. The step change factor 344 may also be calculated by the electronic control process 300 instead of retrieved from the truth table 306, depending on implementation.

[0042] The electronic control process 300 shown in Fig. 3 is just one example layout of control logic for the sake of illustrating electronic fuel control for the electronically controlled fuel valve 116. Many other pressures inside the fuel cell engine 100, and many other combinations of those pressures, may be joined or compared through various logical operators to enable the electronic controller 118 to govern the orifice size of the electronically controlled fuel valve 116 in real time. Many different logic schemata are possible in the electronic controller 118 for controlling the orifice size of one or more electronically controlled fuel valves 116 in real time.

[0043] Fig. 4 shows an example electronic controller 118 capable of executing the electronic control process 300 of Fig. 3. The electronic controller 118 of Fig. 4 is not limited to one control process but can use numerous different control processes or generate a custom electronic control process to govern one or more instances of the electronically controlled fuel valve 116. The electronic controller 118 may adjust the orifice size of one or more electronically controlled fuel valves 116 in gradual changes, increments, or smooth changes, but may also switch to simple on-off, fully-open-or-fully-closed, operation of the electronically controlled fuel valve 116 when the electronic controller 118 concludes that this mode of operation is best for the circumstances at hand.

[0044] Hardware interfaces of the electronic controller 118 include a vehicle interface 400 and a fuel cell engine interface 402. The fuel cell engine interface 402 includes a sensors interface 404 and a valve control interface 406, which may further include a dedicated fuel valve interface 408. The hardware interfaces shown in Fig. 4 may be wired, with plug and socket interfaces for example, or may be wireless in part or in full. When the hardware interfaces are wireless, the electronic controller 118 may include a communicative vehicle bus, such as a Controller Area Network (CAN) defined by SAE J1939 and/or a Local Interconnect Network (LIN). In some instances Wi-Fi, BLUETOOTH, ZIGBEE networking, or other capabilities and/or communication channels may be utilized.

[0045] A state determination module 410 receives data from the vehicle 102 or other machine hosting the fuel cell engine 100. The state determination module 410 queries or otherwise addresses one or more truth tables 306 (lookup tables, binary decision trees, databases) using data from the vehicle 102 as the query to determine a current state of the vehicle 102. In an implementation, the engine control unit 120 or other onboard computer of the vehicle 102 relays the current state of the vehicle 102 to the state determination module

410. A setpoint engine 412 obtains data from the truth table 306, specifically including pressure setpoint data 308 associated with the current state of the vehicle 102, as stored in the truth table 306. As introduced above, the current state of the vehicle 102 may be startup, shutdown, accelerating, decelerating, fuel economy mode, cruising, hauling, idling, cabin cooling, overheating, testing, braking, storing energy, and many other vehicle states that are associated with an amount of electric power to be produced by the fuel cell engine 100.

[0046] The setpoint engine 412 may have a stored setpoint retrieval unit 414 for parsing pressure setpoint data 308 from the truth table 306. Alternatively, the setpoint calculator 416 of the setpoint engine 412 may calculate some or all pressure setpoints, pressure increments, and other data 308 that can be used in a given electronic control process 300. The setpoint engine 412 provides a dynamic setpoint as the first input 314 for the PID control loop 316. The electronic control process 300 of Fig. 3 provides an example of some of the logic that may be used in an example setpoint engine 412.

[0047] A sensor selection module 418 may choose which pressure sensors 242, 246, 248, 250, 252 (for example) to use, combine, compare or link with logical operators to devise one or more pressure setpoints for a given electronic control process 300. The sensors to be selected are not limited to pressure sensors 242, 246, 248, 250, 252 but may be temperature sensors, speed sensors, power sensors, voltage sensors, amperage sensors, or any other data input available in the vehicle 102, machine, or fuel cell engine 100. The selected pressure data 420 is fed directly or indirectly as the second input 318 of the PID control loop 316. The electronic control process 300 of Fig. 3 provides an example of some of the logic that may be used in an example sensor selection module 418 and selected pressure data 420.

[0048] A processor 422 and memory 424 give the example electronic controller 118 computing power to perform functions and calculations and govern the electronically controlled fuel valve 116 in real time. The processor 422 may draw from logic schemata 426 stored in the electronic controller 118 or stored in a separate data storage medium. For example, a timing logic schema of the logic schemata 426 may include information for deciding a scan rate of the electronic controller 118 and PID control loop 316.

[0049] The logic schemata 426 available to the processor 422 may further include a startup logic schema, a shutdown logic schema, a power logic schema, an acceleration logic schema, the timing schema introduced above, a pressure logic schema, a fuel economy logic schema, and a thermal and cooling logic schema, as examples. Other logic schemas may be included in the body of logic schemata 426 available to the processor 422.

[0050] The electronic controller 118 may include a schema modifier 428 for customizing one of the logic schemata 426 based on data: input from the vehicle interface 400; output from the setpoint engine 412; output from the sensor selection module 418; and/or other data available to the electronic controller 118. An artificial intelligence (Al) engine 430 may be included to drive the schema modifier 428 or work independently to maximize efficiency of fuel pressure control or fuel economy, for example. The Al engine 430 may also take part in other components of the electronic controller 118, such as the setpoint engine 412 and the sensor selection module 418.

[0051] In an implementation, the Al engine 430 may apply machine learning from past and ongoing performance of the fuel cell engine 100 to customize the given electronic control process 300 (and one or more of the logic schemata 426) for governing the action of the orifice of the electronically controlled fuel valve 116. A given embodiment of the Al engine 430 may apply one or more Al algorithms when customizing a given electronic control process 300 or logic schema from the body of logic schemata 426. In one implementation, the Al engine 430 uses a “limited memory” type of artificial intelligence to customize or attempt to optimize behavior of the electronically controlled fuel valve 116 in controlling fuel pressure of the hydrogen gas 108 at the anodes 202. In other implementation, the Al engine

430 uses artificial narrow intelligence (ANI) processing schemes and algorithms to customize performance of one or more electronically controlled fuel valves 116 in the fuel cell engine 100.

[0052] Fig. 5 shows an example method 500 of electronically controlling a fuel valve of a fuel cell. In the flow diagram of Fig. 5, operations of the example method 500 are shown in individual blocks. The order in which the operations are described in the example method 500 is not intended to be construed as a limitation, and any number of the described blocks can be combined in any order and/or in parallel to implement the process.

[0053] At block 502, the method 500 includes monitoring multiple pressures of the fuel cell via pressure sensors. A combination of pressures to be monitored for purposes of advanced fuel control in the fuel cell may be selected for each different state or circumstance of the fuel cell or vehicle. Combinations of sensor may be selected from a pre-fuel valve (input) pressure sensor, a post-fuel valve pressure sensor, a pre-anode pressure sensor, a precathode pressure sensor, a post-cathode pressure sensor, and an exhaust pressure sensor, for example.

[0054] At block 504, the method 500 includes calculating a pressure setpoint for a fuel pressure of the fuel cell from the multiple pressures. The pressure setpoint can vary for each cycle of an electronic control cycle, depending on the scan rate of the electronics or programming. The pressure setpoint may depend on the current state of the fuel cell or vehicle, and a current logic schema applied to devise a fuel pressure setpoint from the combination of pressures being monitored.

[0055] At block 506, the method 500 includes controlling an orifice size of an electronically controlled fuel valve of the fuel cell via a feedback control loop based on the calculated pressure setpoint. The feedback control loop may be a PI control process or a PID control process.

[0056] Fig. 6 shows an example method 600 of making a fuel cell engine including an electronically controlled fuel valve. In the flow diagram of Fig. 6, operations of the example method 600 are shown in individual blocks. The order in which the operations are described in the example method 600 is not intended to be construed as a limitation, and any number of the described blocks can be combined in any order and/or in parallel to implement the process.

[0057] At block 602, the method 600 includes joining an electronically controlled fuel valve to a fuel cell engine, the electronically controlled fuel valve including a variable orifice. The variable orifice provides a variable fuel flow or a variable fuel pressure to a cell stack of the fuel cell engine.

[0058] At block 604, the method 600 includes connecting an electronic controller to the fuel cell engine. The electronic controller may be physically connected as a physical unit to the fuel cell engine or may be connected via physical wires, vehicle bus, or wireless connections. The electronic controller does not have to be in one physical unit but can be a distributed electronic controller.

[0059] At block 606, the method 600 includes establishing a communication channel between the electronic controller and the electronically controlled fuel valve. The communication channel may be a communicative vehicle bus, such as a Controller Area Network (CAN) defined by SAE J1939 and/or a Local Interconnect Network (LIN). In a non-vehicle setting, the communication channel may also utilize Wi-Fi, BLUETOOTH, a ZIBBEE network, wires, or other communication channel.

[0060] At block 608, the method 600 includes establishing one or more data links between the electronic controller and a set of sensors for determining pressures in the fuel cell engine. In an implementation, at least some sensors in the fuel cell engine are paired 1 : 1 with a corresponding transmitter to communicate over a vehicle bus protocol.

[0061] At block 610, the method 600 includes configuring the electronic controller to monitor multiple pressures of the fuel cell engine via the pressure sensors, calculate a dynamic pressure setpoint for a fuel pressure of the fuel cell engine from the multiple pressures, and control an orifice size of the variable orifice of the electronically controlled fuel valve based on the dynamic pressure setpoint. The electronic controller is preferably able to choose and apply between multiple logic schemata for each step of monitoring multiple pressures, calculating the dynamic pressure setpoint for each electronic cycle, and controlling the orifice size of the fuel valve in real time.

[0062] In the foregoing specification, embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the scope of the invention, and what is intended by the applicants to be the scope of the invention, is the literal and equivalent scope of the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction.