Method and system for torque control in hybrid vehicles

Abstract

Method comprising: operating a hybrid powertrain (100) to provide torque to vehicle wheels (130) over a predetermined route; distributing torque between an internal combustion engine (110) and an electric machine based on a torque distribution; updating the torque distribution based on a vehicle mass which includes an amount of onboard fuel; and optimizing the torque distribution to increase a rate of change of the amount of onboard fuel and a battery charge state in order to maximize an averaged overall power-to-weight ratio compared to a previous vehicle operation over the predetermined route.

Description

AREA

[0001] The present description generally concerns methods and systems for controlling a vehicle to determine torque transmission between an internal combustion engine and an electric machine. GENERAL STATE OF THE ART / BRIEF OVERVIEW

[0002] A hybrid powertrain can be powered by a combination of an internal combustion engine and an electric machine, such as an electric motor. The electric machine can improve drivability by smoothing out fluctuations in the internal combustion engine's torque output during gear changes. The hybrid powertrain can also include an energy storage module to power the electric machine. To efficiently utilize the vehicle's fuel and the energy stored in the energy storage module, a vehicle's torque demand can be strategically distributed (or shared) between the internal combustion engine and the electric machine.

[0003] Attempts to achieve torque transmission involve mediating torque based on internal combustion engine characteristics. An exemplary approach is presented by Simon, JR. et al. in US patent US2009 / 0204280. In this application, the torque requirement to an internal combustion engine and an electric motor is controlled by a predetermined calibration based on the capacities of the internal combustion engine and the electric motor.

[0004] The inventors of the present invention have, however, recognized potential problems with such systems. For example, when the vehicle is operated on a predetermined route, such as in a race, the vehicle's weight can affect its performance. For instance, a low vehicle weight is preferred to maximize traction. The vehicle weight can be reduced by providing a high level of internal combustion engine torque to increase the consumption of the vehicle's fuel. Furthermore, burning excess fuel during regenerative braking can recharge the energy storage module and extend the range of electric assistance from the electric motor. Ideally, the depletion of energy in the energy storage device and the vehicle's fuel supply should coincide with the end of the race.Battery depletion before the end of the race can result in additional battery weight without any performance benefit. Early depletion of the vehicle's internal fuel during the race can lead to a loss of electric assistance and reduced torque output.

[0005] In one example, the problems described above can be addressed by a method that involves operating a hybrid powertrain to provide torque to the vehicle wheels over a predetermined route; and mediating the torque between an internal combustion engine and an electric machine based on the vehicle mass. In this way, the highest average power-to-weight ratio can be achieved over a predetermined route.

[0006] As an example, optimal torque transmission between an internal combustion engine and an electric machine can be determined by optimizing a cost function built on a vehicle model. For instance, the torque transmission can be optimized to achieve maximum vehicle speed. Alternatively, it can be optimized to achieve an optimal speed profile. The vehicle model can include several functions for calculating vehicle acceleration based on inputs, including the amount of fuel in the vehicle. By incorporating the amount of fuel into the vehicle model, the effect of vehicle mass variations during a race is accounted for when solving the optimization problem for optimal torque transmission.Vehicle model parameters (that is, coefficients and formats of the vehicle model's multiple functions) can be updated at the end of each race based on track data collected during the race and previous races, as well as prior non-racing vehicle operation. The track data can include internal combustion engine torque output, electric motor torque output, vehicle speed, battery charge status, and the amount of fuel in the vehicle at each position on the track. By updating the vehicle, mechanical and environmental changes to the vehicle system are taken into account when determining the optimal torque delivery. For example, mechanical changes might include wear or adjustments to the vehicle's mechanical system; and environmental changes might include variations in weather and road conditions.

[0007] It is understood that the foregoing summary is provided to present, in simplified form, a selection of concepts that are described in more detail in the full description. It is not intended to mention important or essential features of the claimed subject matter, the scope of which is defined solely in the claims following the full description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages mentioned above or in any part of this disclosure. List of characters Fig. Figure 1 shows an example of a hybrid powertrain. Fig. Figure 2 shows an example of an internal combustion engine from the hybrid powertrain. Fig. 1. Fig. Figure 3 shows a block diagram for torque transmission optimization. Fig. Figure 4 shows an exemplary method for controlling the torque transmission of the hybrid powertrain. Fig. 1. Fig. Figure 5 illustrates timelines of torque transmission and exemplary vehicle parameters, while the procedure from Fig. 4 is implemented. DETAILED DESCRIPTION

[0008] The following description concerns systems and methods for controlling torque transmission between an internal combustion engine and an electric machine (such as an electric motor) along a predetermined route in a hybrid powertrain. An example hybrid powertrain is shown in Fig. 1 shown. The powertrain can be in Fig. The two combustion engines shown are included. The torque distribution can be mediated, with the torque mediation levels being generated by an optimization algorithm. Fig. Figure 3 shows a block diagram for torque transmission optimization. The torque transmission levels are optimized based on route data acquired while the vehicle is operating on the predetermined route. The driver demand can be updated based on the optimized torque transmission levels to reduce travel time on the predetermined route. Fig. Figure 4 shows an exemplary procedure for iteratively optimizing torque transmission based on a vehicle model. The vehicle model can be updated with road data during each iteration. Timelines of the torque transmission levels and selected vehicle parameters during the implementation of the procedure are shown. Fig. 4 will be in Fig. 5 illustrates.

[0009] Fig. Figure 1 illustrates an example hybrid powertrain 100 The hybrid powertrain 100 includes a fuel combustion engine110 and an electric motor 120 As a non-restrictive example, the engine includes 110 an internal combustion engine and the engine includes 120 an electric motor. The electric motor 120 It can be configured to use or consume a different energy source than the internal combustion engine. 110 For example, the internal combustion engine 110 consume a liquid fuel (e.g. gasoline) to generate combustion engine power, while the electric motor 120 It can consume electrical energy to generate power for an electric motor. Therefore, a vehicle with a drive system can 100 described as a hybrid electric vehicle (HEV).

[0010] The hybrid powertrain 100It can utilize a variety of different operating modes, depending on the operating conditions to which the vehicle's drive system is exposed. Some of these modes can allow the internal combustion engine to 110 is held in a switched-off state (i.e., set to a switched-off state) in which the combustion of fuel in the internal combustion engine is interrupted. For example, the electric motor 120 Under selected operating conditions, the vehicle is driven via a drive wheel 130 propel, as if by an arrow 122 displayed while the combustion engine 110 is switched off.

[0011] Under other operating conditions, the internal combustion engine 110 be set to a switched-off state (as described above) while the electric motor 120 can be operated to power the energy storage device 150to recharge. For example, the electric motor 120 a wheel torque from the drive wheel 130 received, as seen through the arrow 122 shown, with the electric motor converting the vehicle's kinetic energy into electrical energy for storage in the energy storage device. 150 can be converted, as indicated by the arrow 124 This operation can be described as regenerative braking of the vehicle. Accordingly, the electric motor can 120 In some embodiments, it provides a generator function. However, the generator cannot 160 In other embodiments, instead a wheel torque is derived from the drive wheel. 130 received, with the generator using the vehicle's kinetic energy to store it in the energy storage device. 150 can be converted into electrical energy, as indicated by arrow 162.

[0012] Under other operating conditions, the internal combustion engine 110are operated by burning fuel supplied by the fuel system 140 is received as seen through the arrow 142 displayed. For example, the internal combustion engine 110 to be operated in order to propel the vehicle via the drive wheel 130 to propel, as by the arrow 112 displayed while the electric motor 120 is switched off. Under other operating conditions, both the combustion engine and the combustion engine can be switched off. 110 as well as the electric motor 120 Each must be operated to propel the vehicle via the drive wheel. 130 to propel, as by the arrows 112 or 122 is displayed. A configuration in which both the combustion engine and the electric motor can selectively power the vehicle can be described as a parallel-type vehicle propulsion system. It should be noted that the electric motor 120In some embodiments, the vehicle can be driven via a first set of drive wheels and the internal combustion engine 110 the vehicle can be driven via a second set of drive wheels.

[0013] In other embodiments, the hybrid powertrain 100 It can be configured as an inline vehicle drive system, whereby the internal combustion engine does not directly drive the drive wheels. Rather, the internal combustion engine can 110 to be operated in order to power the electric motor 120 to supply with energy, which in turn powers the drive wheel 130 the vehicle can be propelled, as indicated by the arrow 122 displayed. For example, the internal combustion engine 110 under selected operating conditions, the generator 160 drive, which in turn drives one or more of the electric motors 120 , as indicated by the arrow 114 displayed, or the energy storage device 150, as indicated by the arrow 162 displayed, can supply with electrical energy. Another example is the internal combustion engine. 110 to be operated in order to power the electric motor 120 to drive, which in turn can provide a generator function to convert the combustion engine power into electrical energy, with the electrical energy being available for later use by the electric motor in the energy storage device 150 can be saved.

[0014] The fuel system 140 can have one or more fuel storage tanks 144 for storing fuel on board the vehicle. For example, the fuel tank 144to store one or more liquid fuels, including but not limited to gasoline, diesel, and alcoholic fuels. In some examples, the fuel in the vehicle may be stored as a mixture of two or more different fuels. For example, the fuel tank may 144 be configured to store a mixture of gasoline and ethanol (e.g., E10, E85, etc.) or a mixture of gasoline and methanol (e.g., M10, M85, etc.), supplying these fuels or fuel mixtures to the internal combustion engine 110 can be supplied, as indicated by the arrow 142 displayed. Other suitable fuels or fuel mixtures can be used in the internal combustion engine. 110 They are supplied with fuel, which can then be burned in the internal combustion engine to generate engine power. This engine power can be used to propel the vehicle, as indicated by the arrow. 112displayed, or to display the energy storage device 150 via the electric motor 120 or the generator 160 to recharge.

[0015] In some embodiments, the energy storage device 150 It must be configured to store electrical energy that can be supplied to other electrical consumers on board the vehicle (not the electric motor), including cabin heating and air conditioning, starting the internal combustion engine, headlights, cabin audio and video systems, etc. As a non-restrictive example, the energy storage device 150 include one or more batteries and / or capacitors.

[0016] A control 12 can be powered by one or more of the internal combustion engines 110 , the electric motor 120 , the fuel system 140 , the energy storage device 150 and the generator160 communicate. The control 12 can receive sensory feedback information from one or more of the internal combustion engine 110 , the electric motor 120 , the fuel system 140 , the energy storage device 150 and the generator 160 received. Furthermore, in response to this sensory feedback, the control unit can send control signals to one or more of the internal combustion engines. 110 , the electric motor 120 , the fuel system 140 , the energy storage device 150 and the generator 160 send. The control 12 Can a vehicle operator display an output from the vehicle's propulsion system requested by an operator? 102 receive. For example, the controller can receive sensory feedback from a pedal position sensor. 194 received, which communicates with the pedal 192. The pedal 192This can refer schematically to a brake pedal and / or an accelerator pedal. The configuration of the control system 12 will be in Fig. 2 further explained.

[0017] Friction brakes 118 can attach to the wheels 130 be coupled. A frictional force can be applied to the wheel. 130 can be exerted by the wheel brakes 118 can be activated as indicated by the arrow. 117 displayed. In one example, the wheel brakes can be seen. 118 as a reaction to the driver pressing his foot on a brake pedal 192. In other examples, the control can 12 or one with the control 12 The connected control system can apply or operate the wheel brakes. Similarly, frictional force on the wheels can be reduced by applying the wheel brakes. 118 released in response to the driver taking their foot off the brake pedal.

[0018] The energy storage device 150 can periodically supply electrical energy from a power source 180 received, which is located outside the vehicle (e.g., is not part of the vehicle), as indicated by the arrow 184 displayed. As a non-restrictive example, the hybrid powertrain can be used. 100 be configured as a plug-in hybrid electric vehicle (HEV), with electrical energy being supplied by the energy storage device 150 via a transmission cable for electrical energy 182 from the power source 180 can be supplied. During a recharging operation of the energy storage device 150 from the power source 180 can the electrical transmission cable 182 the energy storage device 150 and the power source 180 electrically couple. While the vehicle's drive system is operating to propel the vehicle, the electrical transmission cable can be connected. 182between the power source 180 and the energy storage device 150 be withdrawn. The control 12 can identify and / or control the amount of electrical energy stored in the energy storage device, which can be referred to as the state of charge (SOC).

[0019] In other embodiments, the electrical transmission cable 182 omitted, whereby electrical energy is transferred to the energy storage device 150 wirelessly from the power source 180 can be received. For example, the energy storage device 150 electrical energy is generated from the power source via one or more forms of electromagnetic induction, radio waves and electromagnetic resonance. 180 record. It follows that any suitable approach to recharging the energy storage device will suffice. 150It can be powered from a source that is not part of the vehicle. In this way, the electric motor can 120 to power the vehicle by using an energy source other than the fuel supplied by the internal combustion engine 110 is used.

[0020] The fuel system 140 It can periodically draw fuel from a fuel source located outside the vehicle. A non-restrictive example is the hybrid powertrain. 100 refueling is achieved by dispensing fuel via a fuel delivery device. 170 is recorded, as indicated by the arrow 172 displayed. In some designs, the fuel tank 144 be designed to store the fuel supplied by the fuel delivery device 170 was recorded until it was used by the internal combustion engine 110is supplied for combustion. In some embodiments, the control unit can display the amount of vehicle-internal fuel that is in the fuel tank. 144 The fuel level is stored and received via a fuel level sensor. The fuel level in the fuel tank is then displayed. 144 The stored information (e.g., as identified by the fuel level sensor) can be communicated to the vehicle operator, for example, via a fuel gauge.

[0021] In an alternative embodiment, (a) sensor(s) can be used. 199 to the hybrid powertrain 100 It must be coupled to measure vehicle conditions, including vehicle speed and vehicle position. The sensor 199 can be controlled 12 be connected.

[0022] The control 12 receives signals from the various sensors Fig. 1 and suspends the various actuators Fig. 1. To adjust the internal combustion engine operation based on received signals and instructions stored in a memory of the control unit. For example, adjusting the internal combustion engine torque may involve adjusting a fuel system actuator to regulate the amount of fuel injected into the internal combustion engine cylinder. The amount of fuel injected into the internal combustion engine can be controlled by adjusting the pulse width of a signal sent to a fuel injection device. Details of the fuel injection device are in Fig. Figure 2 illustrates this. As another example, adjusting the electric motor torque might involve adjusting the current and voltage output of the energy storage device to set the torque output of the electric motor. Similarly, adjusting the brake torque might involve adjusting the actuator within the brakes.118 , in order to adjust the frictional force exerted on the wheel.

[0023] With dedication to Fig. Figure 2 now illustrates a schematic diagram of a cylinder of a multi-cylinder internal combustion engine. 110 The internal combustion engine 110 can be at least partially controlled 12 be controlled. A combustion chamber (i.e., a cylinder) 30 of the internal combustion engine 110 can combustion chamber walls 32 with a piston positioned therein 36 include. In some embodiments, the end face of the piston may 36 inside the cylinder 30 have a shell. The piston 36 can be connected to a crankshaft 40 They must be coupled so that the piston's reciprocating motion is translated into a crankshaft rotation. The crankshaft 40 can be attached to at least one drive wheel of the vehicle (such as the wheel) 130 out of Fig. 1) be coupled. Furthermore, a starter motor can be connected to the crankshaft via a flywheel. 40 must be coupled to initiate a starting process of the internal combustion engine. 110 to enable.

[0024] The combustion chamber 30 can intake air from an intake manifold 44 via an inlet channel 42 absorb combustion gases and expel them via an exhaust duct. 48 drain. The intake manifold 44 and the exhaust duct 48 can be accessed via a suitable inlet valve 52 and exhaust valve 54 selectively with the combustion chamber 30 communicate. In some embodiments, the combustion chamber 30 include two or more inlet valves and / or two or more exhaust valves.

[0025] The inlet valve 52 can be done via an electric valve actuator (EVA) 51 through the control 12 can be controlled. Similarly, the exhaust valve can be controlled. 54via an EVA 53 through the control 12 can be controlled. Alternatively, the variable valve actuator can be electro-hydraulic or any other conceivable mechanism to enable valve actuation. Under certain conditions, the control can 12 which the actors 51 and 53 The signals provided vary to control the opening and closing of the corresponding intake and exhaust valves. The position of the intake valve 52 and exhaust valve 54 can be achieved through valve position sensors 55 or 57 be determined.

[0026] A fuel injection device 66 is shown directly adjacent to the combustion chamber 30 coupled to supply fuel proportionally to the pulse width of the control signal 12 The received FPW signal is injected directly into the fuel. In this way, the fuel injection device... 66a so-called direct injection of fuel into the combustion chamber 30 Ready. The fuel injection device can be mounted, for example, on the side of the combustion chamber or on the top of the combustion chamber. Fuel can be supplied to the fuel injection device. 66 through a fuel system (such as the 140 fuel system from Fig. 1) be supplied.

[0027] An ignition system 88 can the combustion chamber 30 via a spark plug 92 a spark in response to a spark advance signal (SA) from the control unit 12 Provided in selected operating modes. Although external ignition components are shown, in some embodiments the combustion chamber may be 30 or one or more other combustion chambers of the internal combustion engine 10 can be operated in a compression ignition mode with or without a spark plug.

[0028] The intake manifold42 or the intake manifold 44 can a throttle 62 with a throttle valve 64 include. In this particular example, the position of the throttle valve can be included. 64 , or a throttle opening, through the control 12 can be varied via a signal which is provided to an electric motor or an actuator, which the throttle 62 This includes a configuration commonly referred to as an electronic throttle control (ETC). In this way, the throttle can be adjusted. 62 to vary the intake air that enters the combustion chamber 30 is provided alongside other combustion engine cylinders. The position of the throttle valve 64 can the control 12 This information is provided by the throttle position signal TP (throttle position). The intake manifold 42 can use an air mass flow sensor 220and a manifold air pressure sensor 222 to provide the corresponding MAF and MAP signals to the controller 12 include.

[0029] Furthermore, in the disclosed embodiments, an exhaust gas recirculation (EGR) system can remove a desired portion of the exhaust gas from the exhaust manifold. 48 to the intake manifold 44 guide. This example illustrates a high-pressure (HP) EGR channel 240. The provided EGR scope for the intake manifold 44 can be controlled 12 via the HP-EGR valve 242 can be varied. Furthermore, an EGR sensor 244 can be installed within the HP-EGR channel. 240 They must be arranged and provide a display of one or more parameters of the pressure, temperature, and concentration of the exhaust gas.

[0030] According to this, the combustion engine 110furthermore, it includes a compression device, such as a turbocharger or a compressor, which has at least one compressor. 262 includes the section along the intake manifold. 44 is arranged. In the case of a turbocharger, the compressor can 262 at least partially by a turbine 264 (e.g. via a wave) that travels along an exhaust duct 48 is arranged, to be driven. In the case of a compressor, the compressor can 262 at least partially by the internal combustion engine 110 and / or an electric machine and may not include a turbine. Therefore, the level of compression provided to one or more cylinders of the internal combustion engine via a turbocharger or supercharger can be controlled by the system. 12 can be varied.

[0031] According to the illustration, an exhaust gas sensor 226 an emission control device 70Located upstream of the exhaust duct 48 coupled. Regarding the exhaust gas sensor 226 It can be any suitable sensor for providing a reading of the air-fuel ratio of the exhaust gas. The emission control device 70 It can include a three-way catalytic converter as a particulate filter.

[0032] The control 12 is in Fig. 2 shown as a microcomputer, which has a microprocessor unit 202 , Input / Output Ports 204 , an electronic storage medium (e.g., computer-readable) for executable programs and calibration values, which in this specific example is a read-only memory chip 206 shown is a direct access memory. 208 , a keep-alive memory 210 and includes a data bus. The control system 12 In addition to the signals discussed above, various signals can be sent to the internal combustion engine. 110coupled sensors receive, including the measurement of mass air flow (MAF) from an air mass flow sensor 220 ; the engine coolant temperature (ECT) from a temperature sensor 212 , which is attached to a cooling sleeve 214 coupled; a profile ignition pickup signal (PIP) from a Hall effect sensor 218 (or another type) that is attached to the crankshaft 40 coupled; the throttle position (TP) from a throttle position sensor; and a manifold absolute pressure signal, MAP (absolute manifold pressure), from the sensor 222 An internal combustion engine speed signal, RPM, can be obtained through the control unit. 12The manifold pressure signal (MAP) from a manifold pressure sensor can be generated from the PIP signal. It can be used to provide an indication of vacuum or pressure in the intake manifold. It should be noted that various combinations of the aforementioned sensors can be used, such as a MAF sensor without a MAP sensor, or vice versa. In stoichiometric operation, the MAP sensor can provide an indication of the internal combustion engine torque. Furthermore, this sensor, together with the detected internal combustion engine speed, can provide an estimate of the charge (including air) being introduced into the cylinder. In one example, the sensor can 218 , which can also be used as an internal combustion engine speed sensor, generates a predetermined number of evenly spaced pulses per revolution of the crankshaft.

[0033] A storage medium of a read-only memory 106can be programmed with computer-readable data representing instructions to be issued by the microprocessor 202 to carry out the procedures described herein as well as other variants which are assumed but not explicitly listed.

[0034] As described above, shows Fig. 2 merely one cylinder of a multi-cylinder internal combustion engine, and each cylinder can likewise contain its own set of inlet / outlet valves, fuel injection device, spark plug, etc.

[0035] Fig. Figure 3 shows a block diagram for optimizing torque delivery. A torque demanded by a driver was modified by the output of an optimization algorithm, with the goal of reducing race time. The vehicle is controlled by the torque demanded by the driver. Vehicle operating parameters, also referred to here as track data, are recorded and used to optimize torque delivery.

[0036] The torque requested by the driver 301 is connected to a torque transmission module 310 Sent. The torque transmission module modifies the torque requested by the driver. 301 based on the optimization algorithm 330 generated torque transmission 309In one embodiment, the driver requirement is the total torque output of the vehicle for propulsion. The torque requested by the driver can be a mathematical function of the accelerator pedal depressor. For example, the torque requested by the driver could be... 301 be proportional to the degree of depressurization of the accelerator pedal, measured by a pedal position sensor (such as the pedal position sensor) 194 out of Fig. 1) The torque transmission module 310 The torque requested by the driver can be transmitted between the combustion engine and the electric motor based on the torque transmission. 309Distribute the torque. The torque transmission can include an internal combustion engine torque level and an electric motor torque level. The torque levels range from zero to one. The sum of the torque levels is equal to one. For example, the internal combustion engine torque level can be 70% and the electric motor torque level can be 30%. The torque transmission module can provide an internal combustion engine torque requirement. 311 calculate by calculating the torque requested by the driver 301 multiplied by the combustion engine torque level, and an electric motor torque requirement 312 calculate by calculating the torque requested by the driver 301 multiplied by the electric motor torque level.

[0037] In another embodiment, the torque requested by the driver can be 301The system includes a total torque requirement for vehicle propulsion and a base torque assignment. The base torque assignment can be determined based on lookup tables relating to the current vehicle state. If optimization is desired, the torque assignment module can adjust the base torque assignment based on the optimization algorithm. 330 generated torque transmission 309 modify.

[0038] In yet another embodiment, the torque 301 requested by the driver can include a total torque requirement for vehicle propulsion and a braking torque requested by the driver. The braking torque requested by the driver can be negative. The braking torque requested by the driver can be a mathematical function of the depression of a brake pedal. In one example, the torque transmission module can 310In cases where a delay in operation is a problem, the braking torque requested by the driver is applied directly to the vehicle's friction brakes. 320 (such as the brakes) 118 out of Fig. 1) transferred without modification. In another example, the torque transmission module can be used. 310 a negative braking torque requested by the driver between regenerative brakes, combustion engine brakes and / or friction brakes ( 313 ) based on the torque transmission 309 convey.

[0039] The vehicle 320 can be based on the internal combustion engine torque requirement 311 , the electric motor torque requirement 312 and the braking torque requirement 313 They can be operated. For example, parameters such as the amount of fuel, the amount of air charge, and spark plug timing can be used, based on the internal combustion engine's torque requirement. 311to deliver the required combustion engine torque. The current and voltage output of the energy storage device can be determined based on the electric motor torque requirement. 311 The required electric motor torque must be determined so that it can generate the necessary torque. The frictional force exerted on the vehicle wheel can be determined based on the braking torque requirement. During vehicle operation, vehicle parameters (also referred to as route data), including the current vehicle speed, are recorded. 302 , vehicle-internal fuel quantity 303 , battery charge status 304 , Vehicle temperature conditions 305 and the vehicle position on the track, measured and applied to the optimization algorithm 330 feedback. The vehicle's temperature states 305This can include combustion engine temperature, electric motor temperature, and friction brake temperature. The vehicle's position on the track can be three-dimensional. The vehicle's thermal states can be measured or estimated by appropriate temperature sensors integrated into the hybrid powertrain.

[0040] The optimization algorithm 330 determines the optimal torque transmission levels based on the vehicle system 320measured / estimated route data. The optimization algorithm can also take an assumed speed at the vehicle position as input to determine the combustion / electric motor power split. As an example, the optimization algorithm can search for the torque transfer levels that can minimize a cost function. In one embodiment, the cost function can be created with the goal of achieving the assumed speed at a route position. In another embodiment, the cost function can be created with the goal of achieving a minimum route time. The torque transfer levels can be constrained by thermal limitations, such as limitations on the combustion engine temperature, the electric motor temperature, and the friction brake temperature. Details of the optimization algorithm are described in the following section. Fig. 4 developed.

[0041] Fig. 4 shows a procedure 400 for torque control in a hybrid powertrain, such as the hybrid powertrain 100 out of Fig. 1. Instructions for carrying out the procedure 400 and the other procedures included herein can be executed by a controller based on instructions stored in a memory of the controller and in conjunction with signals from sensors of the internal combustion engine system, such as those referred to above. Fig. 1 - Fig. The two sensors described above receive data. The control unit can use combustion engine actuators of the combustion engine system to adjust the combustion engine operation according to the procedures described below.

[0042] At 401The control unit loads the track's torque map, which is stored in its memory. For example, the driver can enter the track identification number, and the control unit will search for and load the corresponding torque map from memory. The stored torque output can be predefined levels stored in memory or the results of previous optimizations. The torque map can include the percentage torque level of the internal combustion engine and an electric machine, such as an electric motor.

[0043] The controller can also load a vehicle model. For example, the vehicle model could be a mathematical function relating the vehicle's acceleration to the required torque for the combustion engine, electric motor, and brakes. The vehicle model could be in the following form: a ( d ) = f 1 ( T e , T I C E , T B , V ( d ) , M V ( d ) ) where d is the vehicle position on the track, which can be three-dimensional; a(d) is the vehicle acceleration; V(d) is the vehicle speed; M V (d) the vehicle mass is; T e The torque of the electric machine is and a negative T e The regenerative braking is; T ICE the internal combustion engine torque; and T B The braking torque provided by the friction blocks is the same. The vehicle mass can be a function of the amount of fuel inside the vehicle. M V ( d ) = f 2 ( F Q T Y ( d ) ) , where F QTY (d) the amount of fuel remaining in the vehicle. The amount of fuel remaining in the vehicle may be a function of the internal combustion engine torque T. ICE act: F Q T Y ( d ) = f 3 ( F I C E , d ) .

[0044] The combustion engine torque T ICEcan it be a function of the internal combustion engine torque requirement u1(d) (such as the internal combustion engine torque requirement) 311 out of Fig. 3) act: T I C E ( d ) = G 1 ( s ) u 1 ( d ) , where G1(s) is a transfer function and s denotes a Laplace transform. The transfer function can model an internal combustion engine delay, including turbocharger delay and the delays of the internal combustion engine actuators. The electric motor torque T e can it be a function of the electric motor torque requirement u2(d) (such as the electric motor torque requirement) 312 out of Fig. 3) act: T e ( d ) = G 2 ( s ) u 2 ( d ) , where G2(s) is the transfer function from the electric motor torque requirement u2(d) to the actual output of the electric motor torque T. eThe transfer function G2(s) can account for a delay in switching the electric motor power source between the energy storage device and the generator. The transfer function G2(s) can also account for a delay in the electric motor's response, such as a delay from receiving the electric motor demand to delivering the required electric motor torque. The braking torque T provided by the braking system B can be equal to the braking torque requirement (such as the braking torque requirement) 313 out of Fig. 3) or the braking torque requested by the driver: T B ( d ) = u 3 ( d ) .

[0045] Loading the vehicle model loads the parameters of the functions f1()-f3() and the transfer functions G1(s) - G2(s). This allows the controller to calculate vehicle acceleration at a given position based on inputs including the internal combustion engine torque requirement, the electric motor torque requirement, the brake torque requirement, and the vehicle speed.

[0046] At 402 The vehicle is operated based on the loaded torque transmission. For example, the torque transmission module (such as the torque transmission module) calculates 310 out of Fig. 3) The internal combustion engine torque requirement, the electric motor torque requirement, and the brake torque requirement are calculated based on the driver's requirements and the charged torque mediation levels from 401. As an example, the internal combustion engine torque requirement is calculated by multiplying the drive torque requested by the driver by the internal combustion engine torque level; the electric motor torque requirement is calculated by multiplying the drive torque requested by the driver by the electric motor torque level; the brake torque requirement is equal to the brake torque requested by the driver. The drive torque requested by the driver can be determined by checking a lookup table with a degree of deceleration of the accelerator pedal.

[0047] At 403 does the procedure measure 400Track data is collected while the vehicle is operating on the racetrack. This track data is measured or estimated at each position along the track. The track data can include the vehicle speed (V) and the amount of fuel in the vehicle (F). QTY , the vehicle acceleration a , the combustion engine torque T ICE , the electric motor torque T E and the braking torque T B include, for example, the procedure 400 The procedure involves measuring the internal combustion engine speed and load, and estimating the internal combustion engine torque output by multiplying the measured engine speed by the measured engine load. 400The procedure can measure the speed and load of the electric motor and estimate the actual electric motor torque output by multiplying the measured electric motor speed by the measured electric motor load. Procedure 400 can measure a braking force and calculate the braking torque as a function of the braking force. Alternatively, one or more of the internal combustion engine torque, electric motor torque, and braking torque can be measured directly with a dynamometer. The track data can further include the thermal state, including the internal combustion engine temperature, the electric motor temperature, and the brake temperature. For example, the internal combustion engine temperature can be estimated based on the coolant temperature, which is measured by a sensor coupled to the coolant system (such as a temperature sensor). 212 out of Fig. 2) is measured. The electric motor temperature and the brake temperature can each be measured by a temperature sensor that is coupled to the electric motor or the brakes, respectively.

[0048] At 404 determines the procedure 400 whether the race track has ended. If the vehicle has not yet completed the race track, the procedure continues 400 At 405, the process continues with measuring / estimating the track data. Once the vehicle has completed the race track, the procedure continues. 400 to 406 above.

[0049] At 406 determines the procedure 400 The procedure checks whether the travel time meets the objective. If the travel time meets the objective, it saves the data. 400At step 409, the current torque transmission levels and the current vehicle model are stored in memory. For example, parameters of the current vehicle model can be stored in memory. If the journey time is longer than the target time, the procedure continues. 400 to 407 above.

[0050] At 407The vehicle model is updated based on the route data acquired at 403. In one embodiment, the vehicle model parameters can be updated based on the route data. The vehicle model parameters can include coefficients and formats of the functions f1() - f3() and the transfer functions G1(s) - G2(s). The function parameters can be determined based on the measured or estimated inputs and outputs. For example, the parameters of the transfer function G1 can be determined based on the internal combustion engine torque requirement u1 and internal combustion engine torque T measured or estimated at 403. ICE can be updated. As another example, the parameters of the function f3() can be updated based on the amount of vehicle fuel F measured or estimated at 403. QTY and combustion engine torque T ICEto be updated. In one embodiment, the parameters of the vehicle model can be updated based on the route data using system identification.

[0051] Furthermore, parameters of the thermal equations can be updated or identified. The thermal equations can be used to calculate the combustion engine temperature, the electric motor temperature, and the brake temperature. The thermal equation for the combustion engine temperature can be a function of the vehicle speed and the combustion engine torque. H I C E ( d ) = f 5 ( V ( d ) , T I C E ( d ) ) .

[0052] The thermal equation for electric motor temperature can be a function of vehicle speed, electric motor torque, and battery charge status: H E ( d ) = f 6 ( V ( d ) , T e ( d ) , F S O C ( d ) ) .

[0053] The heat equation for brake temperature can be a function of vehicle speed and braking torque: H B ( d ) = f 7 ( V ( d ) , T B ( d ) ) .

[0054] At 408 Optimal torque transmission levels are determined based on the updated vehicle model using optimization. If an optimal speed profile is known, the combustion engine torque requirement u1(d), the electric motor torque requirement u2(d), and the brake torque requirement u3(d) can be optimized in one embodiment such that the speed profile approximates the optimal vehicle profile. The optimization problem can be expressed as a first cost function: m i n ( u 1 , u 2 , u 3 ) ‖ V r − ∫ a ‖ st T e m i n ( V ( d ) , F S O C ( d ) ) ≤ T e ( d ) ≤ T e m a x ( V ( d ) , F S O C ( d ) ) , 0 ≤ F S O C ( d ) ≤ 1, 0 ≤ T I C E ( d ) ≤ T I C E m a x ( V ( d ) , F Q T Y ( d ) ) , 0 ≤ F Q T Y ( d ) ≤ 1, T B m i n ( V ( d ) ) ≤ T B ( d ) ≤ 0, H I C E m i n ≤ H I C E ( d ) ≤ H I C E m a x , H E m i n ≤ H E ( d ) ≤ H E m a x , H B m i n ≤ H B ( d ) ≤ H B m a x , <?page 11=""?> where V r This concerns the optimal speed profile. The combustion engine torque T e is determined by the maximum and minimum current electric motor torque, T emax and T emin limited, whereby both the maximum and minimum current electric motor torque, T emax and T emin , which concerns functions of vehicle speed and battery charge status. The combustion engine torque is determined by the maximum available combustion engine torque T. ICEmax limited, where it is a function of the vehicle speed V(d) and the amount of fuel inside the vehicle F qty (d) The braking torque can be determined by a torque T available from the friction brakes. Bminbe limited, which is a function of the vehicle speed.

[0055] If the optimal speed profile is unknown, the combustion engine torque requirement u1(d), the electric motor torque requirement u2(d), and the brake torque requirement u3(d) can be optimized in another embodiment to minimize the average vehicle speed over the route. The optimization problem can be expressed as a second cost function: m i n ( u 1 , u 2 , u 3 ) 1 V a v g , st T e m i n ( V ( d ) , F S O C ( d ) ) ≤ T e ( d ) ≤ T e m a x ( V ( d ) , F S O C ( d ) ) , 0 ≤ F S O C ( d ) ≤ 1, 0 ≤ T I C E ( d ) ≤ T I C E m a x ( V ( d ) , F Q T Y ( d ) ) , 0 ≤ F Q T Y ( d ) ≤ 1, T B m i n ( V ( d ) ) ≤ T B ( d ) ≤ 0, H I C E m i n ≤ H I C E ( d ) ≤ H I C E m a x , H E m i n ≤ H E ( d ) ≤ H E m a x , H B m i n ≤ H B ( d ) ≤ H B m a x , where V avg about the average speed.

[0056] The optimization problem can be solved using several available methods. For example, if the cost function is convex, gradient-based methods can be used. If the function is not convex, genetic and heuristic algorithms can be used.

[0057] The torque transmission can be calculated based on the optimized combustion engine torque requirement u1' and the optimized electric motor torque requirement u2': V e r b r e n n u n g s m o t o r d r e h m o m e n t n i v e a u = u 1 ' u 1 ' + u 2 ' × 100 %; E l e k t r o m o t o r d r e h m o m e n t n i v e a u = u 2 ' u 1 ' + u 2 ' × 100 % .

[0058] The procedure 400 The vehicle then operates using the torque transmission generated based on the optimization.

[0059] Fig. Figure 5 illustrates exemplary timelines of the internal combustion engine torque level. 510 , of the electric motor torque level 520 , battery charge status 530and the amount of in-vehicle fuel 540 , during the procedure 400 This is implemented. The x-axes represent time. Time increases, as indicated by the arrow.

[0060] At T1, the vehicle begins the race on a predetermined route. The control system can load the stored combustion engine torque level and the electric motor torque level at any point along the route. The torque levels remain constant throughout the entire race. That is, from T1 until T2, when the vehicle finishes the race, the combustion engine torque level and the electric motor torque level remain the same. The battery charge level and the amount of onboard fuel decrease steadily from T1 to T2. The track data, including vehicle speed, combustion engine torque output, electric motor torque output, and the amount of onboard fuel, are monitored and recorded.

[0061] At T2, the vehicle finishes the race with a non-zero battery charge and a non-zero amount of internal fuel. The control system compares the race time from T1 to T2 and determines that torque delivery optimization is necessary to improve the race time. Therefore, a vehicle model is updated based on the track data, and the torque delivery is optimized based on this updated vehicle model.

[0062] At T3, the vehicle begins a second race on the same route. The vehicle operates based on optimized torque delivery. From T3 until T4, when the vehicle finishes the second race, the combustion engine torque level decreases and the electric motor torque level increases. The rate of change of the battery charge status is initially low, then increases towards the end of the race. The rate of change of the amount of onboard fuel is high at the beginning of the second race due to the high combustion engine torque level. The rate of change of the amount of onboard fuel decreases towards the end of the race. Both the battery charge status and the amount of onboard fuel are zero at the end of the race at T4. Compared to the first race, the onboard fuel is depleted more quickly, thus reducing the vehicle's weight more rapidly to improve the overall power-to-weight ratio during the race.

[0063] In T4 mode, the control unit determines that the track time for the second race meets the requirements. The torque delivery levels and the vehicle model are stored in the control unit's memory.

[0064] In this way, torque transmission levels between the combustion engine and the electric motor are updated along a predetermined route using an optimization process based on a vehicle model. The vehicle model is updated after each pass along the route based on actual route data. The vehicle model is a function of the amount of fuel in the vehicle.

[0065] The technical benefit of updating the vehicle model is that variations in the vehicle and race conditions can be taken into account. The technical benefit of optimizing the torque delivery levels after each race is that the torque delivery level can be adjusted at any point on the track to effectively utilize the vehicle's onboard fuel and the energy stored in the energy storage device. The technical benefit of creating the vehicle model based on the amount of onboard fuel is that the optimization algorithm can achieve the highest average power-to-weight ratio. The technical benefit of considering the vehicle's thermal states during optimization is that the effects of heat on the power electronics can be taken into account.

[0066] In one example, the method includes operating a hybrid powertrain to provide torque to vehicle wheels along a predetermined route; and mediating the torque between an internal combustion engine and an electric machine based on a vehicle mass. In a first example of the method, the method further includes determining the vehicle mass based on an amount of in-vehicle fuel while the hybrid powertrain is operating. A second example of the method optionally includes the first example and further includes determining the torque mediation between the internal combustion engine and the electric machine based on a vehicle model.A third example of the method optionally includes one or more of the first and second examples and further includes measuring an internal combustion engine torque output and an electric machine torque output while the hybrid powertrain is operating, and identifying the vehicle model based on the measured internal combustion engine torque output, the measured electric machine torque output, and the vehicle mass. A fourth example of the method optionally includes one or more of the first through third examples and further includes identifying the vehicle model based on a measured vehicle speed, a measured amount of in-vehicle fuel, and a measured battery charge status.A fifth example of the procedure optionally includes one or more of the first four examples and further includes determining the torque mediation by calculating the difference between an optimal speed profile and a speed profile calculated based on the identified vehicle model. A sixth example of the procedure optionally includes one or more of the first five examples and further includes determining the mediation by maximizing an average vehicle speed calculated based on the identified vehicle model. A seventh example of the procedure optionally includes one or more of the first six examples and further includes mediating the torque such that the amount of in-vehicle fuel at the end of the route is zero.An eighth example of the procedure optionally includes one or more of the first to seventh examples and further includes that the torque is mediated in such a way that the battery charge status at the end of the route is zero.

[0067] In another embodiment, a method comprises operating a vehicle with a torque transmission between an internal combustion engine and an electric machine over a predetermined route; measuring an amount of in-vehicle fuel; and updating the torque transmission based on the measured amount of in-vehicle fuel to maximize an average power-to-weight ratio over the predetermined route. In a first example of the method, the method further comprises updating the torque transmission based on a vehicle model and updating parameters of the vehicle model based on the measured amount of in-vehicle fuel.A second example of the procedure optionally includes the first example and further includes measuring route data during vehicle operation and updating the vehicle model parameters based on the measured route data. A third example of the procedure optionally includes one or more of the first and second examples and further includes route data that contains internal combustion engine torque, electric machine torque, braking torque, vehicle speed, and battery charge status. A fourth example of the procedure optionally includes one or more of the first through third examples and further includes updating the torque mediation so that a vehicle profile calculated based on the updated torque mediation approximates an optimal vehicle profile.A fifth example of the procedure optionally includes one or more of the first four examples and further includes updating the torque mediation so that an average vehicle speed calculated based on the updated mediation is maximized. A sixth example of the procedure optionally includes one or more of the first five examples and further includes updating the torque mediation so that, at the end of the predetermined route, the amount of in-vehicle fuel has a first threshold and the battery charge status has a second threshold.

[0068] In another embodiment, a hybrid vehicle comprises: a wheel; an internal combustion engine coupled to the wheel; an electric machine coupled to the wheel; a brake coupled to the wheel; and a controller configured by means of computer-readable instructions stored in non-volatile memory to: load a torque broker for a route; operate the vehicle on the route by distributing a torque demand between the internal combustion engine and the electric machine based on the loaded torque broker; measure an amount of in-vehicle fuel while the vehicle is in operation; optimize the torque broker based on the amount of in-vehicle fuel at the end of the route; and store the optimized torque broker.In a first example of the procedure, the procedure further includes configuring the control system to optimize torque delivery based on a vehicle model. A second example of the procedure optionally includes the first example and further includes configuring the control system to update the vehicle model based on the amount of fuel in the vehicle. A third example of the procedure optionally includes one or more of the first and second examples and further includes configuring the control system to operate the vehicle on the route with a braking torque equal to a braking torque requested by the driver.

[0069] It should be noted that the exemplary control and estimation routines included herein can be used with various internal combustion engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-volatile memory and executed by the control system, including the controller, in combination with the various sensors, actuators, and other internal combustion engine hardware. The specific routines described herein can represent one or more from any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Accordingly, various illustrated actions, operations, and / or functions can be performed in the illustrated sequence or in parallel, or in some cases, omitted.Likewise, the processing sequence is not strictly necessary to achieve the features and advantages of the exemplary embodiments described here, but is provided to facilitate illustration and description. One or more of the illustrated actions, processes, and / or functions can be performed repeatedly, depending on the specific strategy employed. Furthermore, the described actions, processes, and / or functions can graphically represent code to be programmed into non-volatile memory of the computer-readable storage medium in the internal combustion engine control system, with the described actions being executed by carrying out the instructions in a system that includes the various internal combustion engine hardware components in combination with the electronic control unit.

[0070] It is understood that the interpretations and routines disclosed herein are exemplary in nature and that these specific embodiments are not to be interpreted in a restrictive sense, as numerous variations are possible. For example, the aforementioned technology can be applied to V-6, I-4, I-6, V-12, 4-cylinder boxer, and other types of internal combustion engines. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the different systems and configurations, and other features, functions, and / or properties disclosed herein.

[0071] The following claims describe, in particular, certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element, "a first" element, or the equivalent thereof. Such claims are to be understood as including one or more such elements and neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application.Such patent claims are, moreover, considered to be included in the subject matter of the present disclosure, irrespective of whether they have a broader, narrower, the same or different scope of protection compared to the original patent claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2009 / 0204280

[0003]

Claims

[1] Procedure, encompassing: Operating a hybrid powertrain to deliver torque to vehicle wheels along a predetermined route; and Transmitting torque between an internal combustion engine and an electric machine based on a vehicle mass. [2] The method of claim 1, further comprising determining the vehicle mass based on an amount of in-vehicle fuel while the hybrid powertrain is operating. [3] Method according to claim 1, further comprising determining the torque transmission between the internal combustion engine and the electric machine based on a vehicle model. [4] Method according to claim 3, further comprising measuring an internal combustion engine torque output and an electric machine torque output while the hybrid powertrain is operated, and identifying the vehicle model based on the measured internal combustion engine torque output, the measured electric machine torque output and the vehicle mass. [5] Method according to claim 4, wherein the vehicle model is further identified based on a measured vehicle speed, a measured amount of in-vehicle fuel and a measured battery charge status. [6] Method according to claim 5, further comprising determining the torque transmission by determining a difference between an optimal speed profile and a speed profile calculated based on the identified vehicle model. [7] Method according to claim 5, further comprising determining the mediation by maximizing an average vehicle speed calculated on the basis of the identified vehicle model. [8] Method according to claim 1, wherein the torque is mediated such that at the end of the route the amount of in-vehicle fuel has a first threshold and a battery charge status has a second threshold. [9] Method according to claim 1, wherein the torque is mediated such that the amount of vehicle-internal fuel at the end of the route is zero. [10] Method according to claim 1, wherein the torque is transmitted such that the battery charge status at the end of the route is zero. [11] Hybrid vehicle, comprising: a wheel an internal combustion engine coupled to the wheel; an electric machine coupled to the wheel; a brake coupled to the wheel; and a controller configured to do the following using computer-readable instructions stored in non-volatile memory: Loading a torque broker for a route; Operating the vehicle on the route by distributing a torque requirement between the combustion engine and the electric machine based on the charged torque mediation; Measuring the amount of fuel consumed by the vehicle while it is in operation; Optimizing torque delivery based on the amount of in-vehicle fuel at the end of the route; and Saving the optimized torque transmission. [12] Hybrid vehicle according to claim 11, further comprising configuring the control system to optimize torque transmission based on a vehicle model. [13] Method according to claim 12, further comprising configuring the control system to update the vehicle model based on the measured amount of vehicle-internal fuel by means of a system identification. [14] Method according to claim 12, further comprising configuring the control system to measure route data during vehicle operation and to update the parameters of the vehicle model based on the measured route data. [15] Method according to claim 12, further comprising configuring the control system to operate the vehicle on the route with a braking torque equal to a braking torque requested by the driver.

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