Method and system for high voltage load arbitration

Abstract

The invention provides a method and system for high voltage load arbitration. A method for operating a hybrid vehicle including a high voltage bus and a low voltage bus is described. In one example, the method includes reducing a high voltage power consumption threshold such that a high voltage bus power consumption device may be identified as a power consumption device that may be deactivated as part of a load shut-off operation. The high voltage power consumption threshold may be based on an amount of power that may be provided via an internal combustion engine and an electric machine.

Description

Technical Field

[0001] This specification relates to methods and systems for arbitrating the load on a high-voltage power bus in a hybrid vehicle. These methods and systems may be advantageous when engine torque is constrained. Background Technology

[0002] Hybrid vehicles may include a high-voltage bus and a low-voltage bus. The low-voltage bus may be electrically connected to a low-voltage battery (e.g., 12VDC). The low-voltage bus can transfer power between low-voltage charging devices, low-voltage storage devices, and low-voltage consuming devices (e.g., vehicle instruments, lighting, infotainment systems, etc.). The high-voltage bus may be electrically connected to a traction battery (e.g., >400VDC). The high-voltage bus can transfer power between the traction battery, climate control systems, power distribution systems for supplying power to external devices, and the electric motor that can provide propulsion. The high-voltage bus can also be electrically connected to the low-voltage bus via a power converter, allowing electrical energy to be transferred from the high-voltage bus to the low-voltage bus. However, sometimes the engine and / or electric motor may lack the capacity to supply power to all electrical consuming devices.

[0003] It is understood that the above background information is provided to give context to the systems and methods described in the specific embodiments. The background information is not intended to identify key features of the claimed subject matter, and the scope of the claimed subject matter is uniquely defined by the claims appended to the specific embodiments. Furthermore, the claimed subject matter is not limited to embodiments that address any shortcomings mentioned above or in any part of this disclosure. Summary of the Invention

[0004] Hybrid vehicles may include a high-voltage bus and a low-voltage bus. Electricity can be transferred between the high-voltage and low-voltage buses via a power converter. During certain vehicle operating conditions, the engine and motor may lack the power output capacity to meet all power requests. In particular, the engine may be power-constrained due to engine knock and / or pre-ignition at lower engine speeds. Therefore, when the power requests from the vehicle cannot be met via the engine and motor alone, power can be supplied to at least some power-consuming devices via the high-voltage battery. However, if the high-voltage battery's state of charge (SOC) drops below a threshold SOC, it may lead to high-voltage battery degradation and / or the power-consuming devices may be unable to receive their requested power.

[0005] The inventors of this paper have recognized the problems mentioned above and have developed a method for operating a vehicle, the method comprising: disconnecting the high-voltage bus electrical load in response to an engine speed below a threshold speed where the high-voltage bus electrical load exceeds the generating capacity of the engine and motor.

[0006] By disconnecting or derating the high-voltage load connected to the high-voltage bus, the following technical result can be achieved: suppressing the reduction of the battery state of charge when a large high-voltage load is applied to the high-voltage bus and the capacity of the internal combustion engine and electric motor is insufficient to supply enough power to meet the demand of the large high-voltage load.

[0007] This specification offers several advantages. Specifically, the method can reduce the likelihood of high-voltage battery degradation. Furthermore, the method can charge the high-voltage battery when its state of charge (SOC) is low and other high-voltage loads are requesting high-voltage power. Additionally, the method assesses high-voltage battery depletion over several time intervals to increase confidence in whether adjusting the high-voltage load threshold is expected to provide benefit.

[0008] The above and other advantages and features of this specification will become readily apparent when understood alone or in conjunction with the accompanying drawings, based on the following detailed description. Attached Figure Description

[0009] Figure 1 A schematic diagram of an internal combustion engine is shown;

[0010] Figure 2 It shows including Figure 1 A schematic diagram of an example vehicle drivetrain or powertrain system for an internal combustion engine, as shown.

[0011] Figure 3 It shows the use of Figure 3 The example proportional / integral controller of the powertrain system shown in the figure; and

[0012] Figure 4 A flowchart is shown as an example method for arbitrating power during selected vehicle operating conditions. Detailed Implementation

[0013] This specification relates to controlling the power distribution of the high-voltage bus and controlling the state of charge (SOC) of the high-voltage battery during operating conditions where the high-voltage battery SOC is low and the engine and / or motor lack the capacity to supply the total amount of electricity consumed via power-consuming devices. The vehicle may include, for example, vehicles with... Figure 1 The image shows a hybrid vehicle with an internal combustion engine. The internal combustion engine can be, for example... Figure 2 This is a part of the hybrid powertrain shown. Electricity in a hybrid vehicle can flow via... Figure 3 The vehicle can be controlled using a proportional / integral (PI) controller of the type shown. Figure 4 The operation is carried out using the following methods.

[0014] refer to Figure 1 Internal combustion engine 10 (including multiple cylinders, Figure 1One of the cylinders shown is controlled by an electronic engine controller 12. The engine 10 consists of a cylinder head 35 and a cylinder block 33, which includes a combustion chamber 30 and cylinder walls 32. A piston 36 is positioned therein and reciprocates via a connection to a crankshaft 40. A flywheel 97 and a ring gear 99 are coupled to the crankshaft 40. A starter 96 (e.g., a low-voltage (operating at less than 20 volts) motor) includes a pinion shaft 98 and a pinion 95. The pinion shaft 98 can selectively advance the pinion 95 to engage the ring gear 99. The starter 96 can be mounted directly to the front or rear of the engine. In some examples, the starter 96 can selectively supply torque to the crankshaft 40 via a chain. In one example, the starter 96 is in a basic state when not engaged with the engine crankshaft.

[0015] Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via corresponding intake lift valve 52 and exhaust lift valve 54. Each intake valve and exhaust valve can be operated by intake cam 51 and exhaust cam 53. The position of intake cam 51 can be determined by intake cam sensor 55. The position of exhaust cam 53 can be determined by exhaust cam sensor 57. The lift and / or phase or position of intake valve 52 can be adjusted relative to crankshaft 40 via valve adjuster 59. The lift and / or phase or position of exhaust valve 54 can be adjusted relative to crankshaft 40 via valve adjuster 58. Valve adjusters 58 and 59 can be electromechanical, hydraulic, or mechanical devices.

[0016] Engine 10 includes a crankcase 39 that houses a crankshaft 40. An oil pan 37 may form the lower boundary of the crankcase 39 and engine block 33, and a piston 36 may form the upper boundary of the crankcase 39. The crankcase 39 may include a crankcase ventilation valve (not shown) that can exhaust gases to the combustion chamber 30 via an intake manifold 44. The temperature of the oil in the crankcase 39 can be sensed via a temperature sensor 38.

[0017] Fuel injector 66 is shown positioned to inject fuel directly into cylinder 31, which is referred to as direct injection by those skilled in the art. Fuel injector 66 delivers liquid fuel in proportion to the pulse width from controller 12. Fuel is delivered to fuel injector 66 via a fuel system (not shown), which includes a fuel tank, a fuel pump, and a fuel rail (not shown). In one example, a high-pressure two-stage fuel system may be used to generate higher fuel pressure.

[0018] Additionally, intake manifold 44 is shown communicating with turbocharger compressor 162 and engine intake port 42. In other examples, compressor 162 may be a supercharger compressor. Shaft 161 mechanically connects turbocharger turbine 164 to turbocharger compressor 162. Optional electronic throttle 62 adjusts the position of throttle plate 64 to control airflow from compressor 162 to intake manifold 44. Since the inlet of throttle 62 is within boost chamber 45, the pressure in boost chamber 45 may be referred to as throttle inlet pressure. Throttle outlet is in intake manifold 44. In some examples, throttle 62 and throttle plate 64 may be positioned between intake valve 52 and intake manifold 44, such that throttle 62 is an intake manifold throttle. Compressor recirculation valve 47 may be selectively adjustable to multiple positions between fully open and fully closed. The exhaust valve 163 can be adjusted via controller 12 to allow exhaust gas to selectively bypass turbine 164, thereby controlling the speed of compressor 162. Air filter 43 cleans the air entering engine intake 42.

[0019] Distributorless ignition system 88 provides an ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12. Universal exhaust oxygen (UEGO) sensor 126 is shown coupled to exhaust manifold 48 upstream of catalytic converter 70. Alternatively, dual-state exhaust oxygen sensor may replace UEGO sensor 126.

[0020] In one example, converter 70 may include multiple catalyst bricks. In another example, multiple emission control devices, each having multiple bricks, may be used. In one example, converter 70 may be a ternary catalyst.

[0021] Controller 12 in Figure 1The controller 12 is shown as a conventional microcomputer, which includes a microprocessor unit 102, an input / output port 104, a read-only memory 106 (e.g., non-transitory memory), a random access memory 108, a keep-alive memory 110, and a conventional data bus. The controller 12 is shown to receive various signals from sensors coupled to the engine 10 in addition to those previously discussed, including: cylinder head temperature from a temperature sensor 112 coupled to the cylinder head 35; a position sensor 134 coupled to the driver's demand pedal 130 for sensing the force applied by a human foot 132; a position sensor 154 coupled to the vehicle brake caliper pedal 150 for sensing the force applied by the foot 152; a measurement of engine manifold pressure (MAP) from a pressure sensor 122 coupled to the intake manifold 44; an engine position sensor 118 for sensing the position of the crankshaft 40; a measurement of the mass of air entering the engine from sensor 120; and a measurement of the throttle position from sensor 68. Atmospheric pressure (sensor not shown) can also be sensed for processing by controller 12. In a preferred aspect of this specification, the engine position sensor 118 generates a predetermined number of equidistant pulses for each revolution of the crankshaft, thereby determining the engine speed (RPM).

[0022] During operation, each cylinder within engine 10 typically undergoes a four-stroke cycle: this cycle includes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. During the intake stroke, generally, the exhaust valve 54 is closed and the intake valve 52 is open. Air is introduced into combustion chamber 30 via intake manifold 44, and piston 36 moves to the bottom of the cylinder to increase the volume within combustion chamber 30. The position of piston 36 near the bottom of the cylinder and at the end of its stroke (e.g., when combustion chamber 30 is at its maximum volume) is generally referred to by those skilled in the art as bottom dead center (BDC).

[0023] During the compression stroke, intake valve 52 and exhaust valve 54 are closed. Piston 36 moves toward the cylinder head to compress the air within combustion chamber 30. The point at which piston 36 is at the end of its stroke and closest to the cylinder head (e.g., when combustion chamber 30 is at its minimum volume) is commonly referred to by those skilled in the art as top dead center (TDC). Fuel is introduced into the combustion chamber during what is hereinafter referred to as injection. The injected fuel is ignited by a known ignition device, such as spark plug 92, resulting in combustion.

[0024] During the expansion stroke, the expanding gas pushes piston 36 back to the BDC. Crankshaft 40 converts the piston movement into rotational torque on the rotating shaft. Finally, during the exhaust stroke, exhaust valve 54 opens to release the combusted air-fuel mixture into exhaust manifold 48, and piston returns to the TDC. It should be noted that the above is merely illustrative, and the opening and / or closing timing of the intake and exhaust valves can vary, such as to provide positive or negative valve overlap, delayed intake valve closing, or various other examples.

[0025] Figure 2 It is a block diagram of a vehicle 225 including a powertrain or transmission system 200. Figure 2 The power transmission system includes Figure 1 The engine 10 is shown. The powertrain 200 is shown as including a vehicle system controller 255, an engine controller 12, an electric motor controller 252, a transmission controller 254, an energy storage device controller 253, and a friction brake caliper controller 250. The controllers can communicate via a controller area network (CAN) 299. Each controller can provide information to the other controllers, such as power output thresholds (e.g., power output of devices or components that are controlled to be exceeded), power input thresholds (e.g., power input of devices or components that are controlled to be exceeded), power output of controlled devices, sensor and actuator data, and diagnostic information (e.g., information about a deteriorated transmission, information about a deteriorated engine, information about a deteriorated electric motor, and information about a deteriorated brake caliper). Furthermore, the vehicle system controller 255 can provide commands to the engine controller 12, the electric motor controller 252, the transmission controller 254, and the brake caliper controller 250 to fulfill driver input requests and other requests based on vehicle operating conditions.

[0026] For example, in response to the driver releasing the driver demand pedal and the vehicle speed, the vehicle system controller 255 can request desired wheel power or wheel power levels to provide a desired vehicle deceleration rate. The requested desired wheel power can be provided by the vehicle system controller 255 requesting a first vehicle deceleration power from the motor controller 252 and a second vehicle deceleration power from the engine controller 12, which provide the desired drivetrain vehicle deceleration power at the vehicle wheels 216. The vehicle system controller 255 can also request friction brake caliper power via the brake caliper controller 250. Vehicle deceleration power can be referred to as negative power because it reduces the rotational speed of the drivetrain and wheels. Positive power can maintain or increase the rotational speed of the drivetrain and wheels.

[0027] The vehicle controller 255 and / or engine controller 12 can also receive input from the human-machine interface 256 and traffic conditions (e.g., traffic signal status, distance to objects, etc.) from sensors 257 (e.g., cameras, lidar, radar, etc.). In one example, the human-machine interface 256 may be a touch input display panel. Alternatively, the human-machine interface 256 may be a push-button switch or other known types of human-machine interface. The human-machine interface 256 can receive requests from the user. For example, the user can request the engine to stop or start via the human-machine interface 256. Furthermore, when an external power consumption device 297 is connected to the vehicle 255, the user can override the restriction on the movement of the wheels 216. Additionally, the human-machine interface 256 can display status messages and engine data that can be received from the controller 255.

[0028] In other examples, the division of the control power transmission system device can be compared with... Figure 2 The different methods of division shown are illustrated. For example, a single controller may replace the vehicle system controller 255, engine controller 12, electric motor controller 252, transmission controller 254, and brake caliper controller 250. Alternatively, the vehicle system controller 255 and engine controller 12 may be a single unit, while the electric motor controller 252, transmission controller 254, and brake caliper controller 250 may be independent controllers.

[0029] In this example, the powertrain 200 can be powered by engine 10 and electric motor 240. In other examples, engine 10 may be omitted. Engine 10 can be utilized via an integrated starter / generator BISG 219 or via an electric motor. Figure 1 The engine is started using the engine starting system shown. The temperature of the BISG winding can be determined via the BISG winding temperature sensor 203. The motor 240 (e.g., a high-voltage (operating at greater than 30 volts) motor) may also be referred to as a motor and / or generator. Furthermore, the power of the engine 10 can be adjusted via torque actuators 204 such as fuel injectors and throttle valves.

[0030] BISG 219 is mechanically connected to engine 10 via chain 231, and BISG 219 may be referred to as an electric motor, generator, or generator. BISG 219 may be connected to crankshaft 40 or camshaft (e.g., Figure 1(51 or 53). BISG 219 can function as a motor when powered via low-voltage bus 273 and / or low-voltage battery 280. BISG 219 can also function as a generator supplying power to low-voltage battery 280 and / or low-voltage bus 273. Power converter 281 (e.g., bidirectional DC / DC converter) can transfer electrical energy from high-voltage bus 274 to low-voltage bus 273, or vice versa. Low-voltage battery 280 is directly electrically connected to low-voltage bus 273. Low-voltage bus 273 can consist of one or more electrical conductors. Energy storage device 275 (e.g., high-voltage battery or traction battery) is electrically connected to high-voltage bus 274. Positive temperature coefficient (PTC) electric heater 266 and electrically driven climate control system (e.g., heat pump) 267 are also electrically connected to high-voltage bus 274 and can receive power via high-voltage bus 274. Low-voltage battery 280 can selectively supply electrical energy to starter motor 96 and / or BISG 219.

[0031] Engine output power can be transmitted via dual-mass flywheel 215 to the first or upstream side 235 of the powertrain release clutch. The release clutch 236 can be hydraulically actuated, and the hydraulic pressure within the powertrain release clutch 236 (powertrain release clutch pressure) can be adjusted via electric valve 233. The downstream or second side 234 of the release clutch 236 is shown as mechanically connected to the motor input shaft 237.

[0032] Motor 240 can be operated to provide power to power transmission system 200, or in regenerative mode to convert power transmission system power into electrical energy for storage in energy storage device 275. Motor 240 is in electrical communication with energy storage device 275 via inverter 279. Inverter 279 can convert direct current (DC) power from energy storage device 275 into alternating current (AC) power to operate motor 240. Alternatively, inverter 279 can convert AC power from motor 240 into DC power for storage in energy storage device 275. Inverter 279 can be controlled via motor controller 252. Motor 240 has a higher... Figure 1The starter 96 or BISG 219 shown has a higher output power capacity. Furthermore, the motor 240 directly drives or is directly driven by the powertrain 200. No gears or chains connect the motor 240 to the powertrain 200. Instead, the motor 240 rotates at the same rate as the powertrain 200. The energy storage device 275 (e.g., a high-voltage battery or power source) can be a battery, capacitor, or inductor. The downstream side of the motor 240 is mechanically coupled to the pump wheel 285 of the torque converter 206 via shaft 241. The upstream side of the motor 240 is mechanically coupled to the disengagement clutch 236. The motor 240 can provide positive or negative power to the powertrain 200 by acting as a motor or generator as instructed by the motor controller 252.

[0033] A power converter 278 (e.g., an inverter) is shown electrically connected to an energy storage device 275 via a high-voltage bus 274 and an electrical output socket 295. The power converter 278 can convert DC power to AC power for operating external power-consuming devices 297 (e.g., hand tools, entertainment systems, lighting, pumps, etc.). The power converter 278 can convert power from a low-voltage battery 280, power from the energy storage device 275, or power from a motor 240 or BISG 219 into power delivered to the electrical output socket 295. External power-consuming devices 297 may be located outside the vehicle 225, or they may be added to the vehicle 225. External power-consuming devices 297 can be electrically connected to the electrical output socket 295 via a power line 296. An external power-consuming device sensor 298 can detect the presence or absence of external power-consuming devices 297. The power consumption device sensor 298 can physically sense the presence of the wire 296 via a switch input, or alternatively, the sensor 298 can be a current sensor and detect the current flowing out of the power output socket 295 to determine the presence or absence of the external power consumption device 297.

[0034] Torque converter 206 includes turbine 286 to output power to input shaft 270. Input shaft 270 mechanically connects torque converter 206 to automatic transmission 208. Torque converter 206 also includes torque converter bypass lock-up clutch 212 (TCC). When TCC 212 is locked, power is transmitted directly from pump wheel 285 to turbine 286. TCC 212 is electrically operated by controller 254. Alternatively, TCC can be hydraulically locked. In one example, torque converter 206 may be referred to as a component of the transmission.

[0035] When the torque converter lock-up clutch 212 is fully disengaged, the torque converter 206 transmits engine power to the automatic transmission 208 via fluid transfer between the torque converter turbine 286 and the torque converter pump impeller 285, thereby doubling the torque. Conversely, when the torque converter lock-up clutch 212 is fully engaged, engine output power is transmitted directly to the input shaft 270 of the transmission 208 via the torque converter clutch. Alternatively, the torque converter lock-up clutch 212 can be partially engaged, thereby allowing adjustment of the amount of power delivered directly to the transmission. The transmission controller 254 can be configured to adjust the electrical force transmitted by the torque converter 206 by adjusting the torque converter lock-up clutch in response to various engine operating conditions or based on driver-based engine operation requests.

[0036] The torque converter 206 also includes a pump 283 that pressurizes fluid to operate the disengagement clutch 236, the forward clutch 210, and the gear clutch 211. The pump 283 is driven via a pump wheel 285 that rotates at the same speed as the motor 240.

[0037] Automatic transmission 208 includes a gear position clutch 211 and a forward clutch 210 for selectively engaging and disengaging forward gears 213 (e.g., gears 1 to 10) and reverse gear 214. Automatic transmission 208 is a fixed-ratio transmission. Alternatively, transmission 208 may be a continuously variable transmission (CVT) capable of simulating both fixed-ratio transmissions and fixed-ratio transmissions. Gear position clutch 211 and forward clutch 210 can be selectively engaged to change the ratio of the actual total revolutions of the input shaft 270 to the actual total revolutions of the wheels 216. Gear position clutch 211 can be engaged or disengaged by adjusting the fluid supplied to the clutches via shift control solenoid valve 209. Power output from automatic transmission 208 can also be relayed to wheels 216 via output shaft 260 to propel the vehicle. Specifically, automatic transmission 208 can transmit input drive power at input shaft 270 in response to vehicle driving conditions before transmitting output drive power to wheels 216. The transmission controller 254 selectively activates or engages the TCC 212, the gear clutch 211, and the forward clutch 210. The transmission controller also selectively deactivates or disengages the TCC 212, the gear clutch 211, and the forward clutch 210.

[0038] Furthermore, friction can be applied to wheel 216 by engaging friction brake caliper 218. In one example, friction brake caliper 218 may engage in response to a human driver pressing their foot on the vehicle brake caliper control pedal (not shown) and / or in response to a command within brake caliper controller 250. Additionally, brake caliper controller 250 may engage friction brake caliper 218 in response to information and / or requests from vehicle system controller 255. Similarly, friction on wheel 216 can be reduced by disengaging friction brake caliper 218 in response to a human driver releasing their foot from the brake caliper pedal, brake caliper controller commands and / or vehicle system controller commands and / or information.

[0039] In response to a request from the moving vehicle 225, the vehicle system controller 255 may obtain a driver power demand or power request from the driver demand pedal or other device. The vehicle system controller 255 then allocates a small portion of the requested driver power demand to the engine and the remainder to the electric motor or BISG. The vehicle system controller 255 requests engine power from the engine controller 12 and electric motor power from the electric motor controller 252. If the electric motor power plus the engine power is less than a transmission input power threshold (e.g., a power input threshold that must not be exceeded), power is delivered to the torque converter 206, which then relays at least a share of the requested power to the transmission input shaft 270. The transmission controller 254 may selectively lock the torque converter clutch 212 and engage a gear via the gear clutch 211 in response to a shift schedule and TCC lock-up schedule that can be based on input shaft power and vehicle speed. In some situations, when it may be desirable to charge the energy storage device 275, charging power (e.g., negative electric motor power) may be requested when a non-zero driver power demand exists. The vehicle system controller 255 can request increased engine power to overcome charging power and meet the driver's power requirements.

[0040] Therefore, the power control of various powertrain components can be supervised by the vehicle system controller 255, which provides local power control of the engine 10, transmission 208, motor 240 and friction brake caliper 218 via the engine controller 12, motor controller 252, transmission controller 254 and brake caliper controller 250.

[0041] As an example, engine power output can be controlled by controlling the throttle opening and / or valve timing, valve lift, and boost adjustment spark timing, fuel pulse width, fuel pulse timing, and / or air charging combination of a turbocharged or supercharged engine. In the case of a diesel engine, controller 12 can control engine power output by controlling a combination of fuel pulse width, fuel pulse timing, and air charging. Engine deceleration power or negative engine power can be provided by rotating the engine when the power generated is insufficient to rotate it. Therefore, the engine can generate deceleration power by operating at low power while burning fuel, where one or more cylinders are deactivated (e.g., no fuel is burned), or where all cylinders are deactivated and the engine is rotated simultaneously. The amount of engine deceleration power can be adjusted by adjusting the engine valve timing. Engine valve timing can be adjusted to increase or decrease engine compression work. Furthermore, engine valve timing can be adjusted to increase or decrease engine expansion work. In all cases, engine control can be performed cylinder-by-cylinder to control engine power output.

[0042] The motor controller 252 can control the power output and electrical energy generation from the motor 240 by adjusting the current flowing into and out of the field winding and / or armature winding of the motor 240, as is known in the art.

[0043] The transmission controller 254 receives the transmission input shaft position via position sensor 271. The transmission controller 254 can convert the transmission input shaft position into an input shaft speed by differentiating the signal from position sensor 271 or by counting a number of known angular distance pulses within a predetermined time interval. The transmission controller 254 can receive the transmission output shaft torque from torque sensor 272. Alternatively, sensor 272 can be a position sensor or a torque and position sensor. If sensor 272 is a position sensor, the controller 254 can count shaft position pulses within a predetermined time interval to determine the transmission output shaft speed. The transmission controller 254, engine controller 12, and vehicle system controller 255 can also receive additional transmission information from sensor 277, which may include, but is not limited to, pump output line pressure sensors, transmission hydraulic sensors (e.g., gear clutch fluid pressure sensors), ISG temperature sensors and BISG temperature sensors, shift lever sensors, and ambient temperature sensors. The transmission controller 254 can also receive a requested gear input from shift selector 290 (e.g., a human / machine interface device). The shift selector 290 may include positions for gears 1-X (where X is the highest gear), D (Drive), Neutral (N), and P (Park). Movement of the shift lever 293 of the shift selector 290 can be prevented via a solenoid actuator 291, which selectively prevents the shift lever 293 from moving from Park or Neutral to a reverse or drive position (e.g., Drive).

[0044] The brake caliper controller 250 receives wheel speed information via wheel speed sensor 221 and receives vehicle deceleration requests from vehicle system controller 255. The brake caliper controller 250 can also receive information directly or via CAN 299 from... Figure 1 The brake caliper pedal sensor 154 shown receives vehicle brake caliper control pedal position information. The brake caliper controller 250 can provide deceleration in response to wheel power commands from the vehicle system controller 255. The brake caliper controller 250 can also provide anti-lock braking and vehicle stability brake caliper activation to improve vehicle stability. Therefore, the brake caliper controller 250 can provide the vehicle system controller 255 with wheel power thresholds (e.g., a threshold of negative wheel power that must not be exceeded) so that negative ISG power does not cause the wheel power threshold to be exceeded. For example, if the brake caliper controller 250 issues a negative wheel torque threshold of 50 N-m, the motor power is adjusted to provide a negative torque of less than 50 N-m (e.g., 49 N-m) at the wheel, including compensating for transmission gearing.

[0045] Figure 1 and Figure 2The system provides a vehicle system comprising: an internal combustion engine; an electric motor; a traction battery; a high-voltage bus electrically connecting the electric motor to the traction battery; and a controller including executable instructions stored in a non-transitory memory, the executable instructions causing the controller to reduce a high-voltage load threshold in response to the depletion of the state of charge (SOC) of the traction battery over multiple time intervals. In a first example, the vehicle system further includes additional executable instructions stored in the non-transitory memory, the additional executable instructions causing the controller to reduce the high-voltage load threshold via a proportional / integral (PI) controller. In a second example that may include the first example, the vehicle system includes: wherein the high-voltage load threshold is the output of the PI controller, and wherein a minimum target traction battery SOC is the input of the PI controller. In a third example that may include one or both of the first and second examples, the vehicle system includes: wherein the high-voltage load threshold is an electrical force that can be transmitted via the high-voltage bus. In a fourth example that may include one or more of the first to third examples, the vehicle system includes: wherein the high-voltage load threshold is based on a maximum electrical load supported via the internal combustion engine and the electric motor. In a fifth example, which may include one or more of the first to fourth examples, the vehicle system includes: wherein the high-voltage load threshold is further based on low-voltage bus load and buffer load. In a sixth example, which may include one or more of the first to fifth examples, the vehicle system further includes additional executable instructions that cause the controller to derate high-voltage power-consuming devices electrically connected to the high-voltage bus (e.g., limit the power flowing to the device to less than the maximum rated power flowing to the device) in response to the high-voltage load threshold. In a seventh example, which may include one or more of the first to sixth examples, the vehicle system further includes a transmission coupled to an electric motor and additional executable instructions that cause the controller to reduce the high-voltage load threshold when the transmission is engaged in drive gear.

[0046] Now for reference Figure 3This diagram illustrates a block diagram of an example proportional / integral (PI) controller for high-voltage load arbitration based on engine torque constraints. The PI controller 300 receives a target minimum high-voltage battery state of charge (SOC). The target minimum high-voltage battery SOC is the lowest SOC level at which the high-voltage battery is intentionally controlled to achieve desired vehicle performance and high-voltage battery energy. The target minimum high-voltage battery SOC is input to node 304, where the current high-voltage battery (e.g., traction battery) SOC is subtracted from the target minimum high-voltage battery SOC. The output of node 304 is input to proportional gain block 306 and integral gain block 308. Proportional gain block 306 multiplies the value output from node 304 by a real number. The real number can be a fixed value, or its value can be a function of operating conditions such as battery temperature. Proportional gain block 306 provides the result of the multiplication to node 310. Integral gain block 308 numerically integrates the output from node 304 and provides the result of the numerical integration to node 310. Node 310 adds the output of proportional gain block 306 and the output of integral gain block 308. The output of node 310 is the high-voltage load threshold (e.g., the maximum electrical force that the engine, motor, and / or battery can output under its current operating conditions).

[0047] refer to Figure 4 A flowchart illustrating a method for arbitrating the power of a hybrid vehicle during selected vehicle operating conditions is shown. At least a portion of method 400 can be implemented as executable controller instructions stored in a non-transitory memory. Method 400 can be used with... Figure 1 and Figure 2 The system coordinates the operation. Additionally, part of method 400 may involve actions in the physical world to change the operating state of the actuator or device.

[0048] At 402, method 400 determines the vehicle operating condition. The vehicle operating condition can be determined or estimated via various sensors described herein. The vehicle operating condition may include, but is not limited to, high-voltage battery SOC, engine torque, engine speed, vehicle speed, high-voltage battery voltage, high-voltage battery current, low-voltage battery voltage, low-voltage battery current, catalyst temperature, driver-demanded torque, engine temperature, and ambient temperature and pressure. Method 400 proceeds to 404.

[0049] At 404, method 400 determines whether selected conditions have been met to initiate high-voltage load arbitration of the hybrid vehicle based on engine torque constraints. In one example, selected conditions may include the vehicle speed being less than a threshold speed, the internal combustion engine operating within a predetermined percentage of the maximum available engine torque at the current engine speed, the high-voltage battery SOC being depleted beyond a predetermined threshold, and the vehicle being engaged in drive, park, or neutral. If so, the answer is yes, and method 400 proceeds to 406. Otherwise, the answer is no, and method 400 proceeds to exit.

[0050] At 406, method 400 samples (e.g., measures and / or determines) the SOC change of the high-voltage battery at multiple predetermined time intervals. For example, method 400 may monitor and track the SOC change of the high-voltage battery at the following time intervals: ten seconds, thirty seconds, sixty seconds, three hundred seconds, and one thousand two hundred seconds. Method 400 proceeds to 408.

[0051] At 408, method 400 determines whether the high-voltage battery SOC has been depleted within a predetermined time interval. For example, method 400 can determine whether the high-voltage battery SOC has decreased within a predetermined portion or a predetermined number of predetermined time intervals. For example, if method 400 determines that the high-voltage battery SOC has been depleted within time intervals of 30 seconds, 60 seconds, and 300 seconds, then method 400 can determine that the high-voltage battery SOC has been depleted within the predetermined time interval. If method 400 determines that the high-voltage battery SOC has been depleted within the predetermined time interval, the answer is yes and method 400 proceeds to 410. Otherwise, the answer is no, and method 400 returns to 406.

[0052] At 410, method 400 determines the maximum electrical load (e.g., maximum electrical force) that can be supported without discharging the high-voltage battery. In one example, the maximum electrical force that can be supported without discharging the high-voltage battery may be the electrical force that can be generated via engine 10 and motor 240. The maximum electrical force can be expressed by the following equation:

[0053] Totelec=Engpow(n, afr, temp, spk, camtime, bp, ambT)·η elec (nele, Tele)

[0054] Where Totalec is the total electrical power that can be provided by the engine and motor under the current operating conditions, Engpow is a function that returns the engine power based on engine speed n, engine air-fuel ratio afr, engine temperature t, engine spark spk, engine cam timing camtime, atmospheric pressure bp, and ambient air temperature ambT. elec This is a function that returns the efficiency of the motor in converting mechanical power into electrical power, where nele is the motor speed and Tele is the motor temperature. Method 400 proceeds to 412.

[0055] At 412, method 400 estimates the current low-voltage battery low-voltage load. In one example, method 400 estimates low-voltage power usage by multiplying the voltage of the low-voltage bus by the amount of current flowing through the low-voltage bus. Alternatively, method 400 may query low-voltage load consuming devices, and these devices may report their power consumption to method 400. Method 400 can then sum the power consumed by the low-voltage power consuming devices to determine the low-voltage power consumption. Method 400 proceeds to 414.

[0056] At 414, method 400 subtracts the low-voltage power consumption and adds a predetermined buffer power to the total power determined in step 410 to determine the high-voltage load threshold amount (e.g., the power that an engine, motor, and / or high-voltage battery can supply to a power-consuming device receiving power via a high-voltage bus). Method 400 proceeds to 416.

[0057] At 416, method 400 reduces the high-voltage load so that the high-voltage battery SOC stops depleting. Method 400 can reduce the high-voltage load according to a predetermined schedule and based on the priority of the high-voltage load. For example, method 400 can reduce the climate control load before reducing the power supplied to the low-voltage load via the high-voltage bus. The high-voltage load can be completely deactivated, or the power supplied to the high-voltage load can be gradually reduced so that the high-voltage battery SOC stops depleting. After the high-voltage battery SOC stops depleting, the reduction of the high-voltage load can stop. Method 400 proceeds to 418.

[0058] At point 418, method 400 is applied. Figure 3The PI controller shown allows high-voltage bus power consumption to be reduced to a state where the high-voltage battery begins to charge from the charge generated via the engine and motor. By lowering the high-voltage battery load threshold, the power supplied to the high-voltage power-consuming devices can be reduced. The flow of high-voltage power supplied to the high-voltage power-consuming devices can be reduced by constraining the power supplied (e.g., de-rating the power supplied to the power-consuming devices). For example, the power supplied to the electric-driven climate control system can be reduced from 4 kW to 3.8 kW. In some examples, the high-voltage power supplied to the high-voltage power-consuming devices can be weighted according to the device type of the high-voltage power-consuming device. For example, the high-voltage power supplied to the low-voltage bus via power converter 281 can have a higher priority weight than the high-voltage power supplied to the climate control system, such that a portion of the power supplied to the low-voltage bus can be greater than a portion of the power supplied to the climate control system. Alternatively, in response to increasing the high-voltage bus load threshold, one or more of the high-voltage power-consuming devices can be disabled (e.g., power load cut-off) to reduce their high-voltage power consumption. Once the total electrical load is low enough, charging of the high-voltage battery can begin, allowing the high-voltage battery SOC to be adjusted to the target minimum high-voltage battery SOC. Method 400 proceeds to 420.

[0059] At 420, method 400 determines whether the high-voltage battery is at or above the target minimum high-voltage battery SOC. If so, the answer is yes and method 400 returns to 404. Otherwise, the answer is no and method 400 returns to 418.

[0060] In this way, method 400 can adjust the power supplied to high-voltage power-consuming devices in response to the power capacity of the engine and motor, so that the state of charge (SOC) of the high-voltage battery may not decrease beyond a potentially desirable level. Additionally, method 400 controls which power-consuming devices can be prioritized.

[0061] therefore, Figure 4The method provides a way to operate a vehicle, the method comprising: disconnecting a high-voltage bus electrical load in response to an engine speed below a threshold speed where the high-voltage bus electrical load exceeds the generating capacity of the engine and motor. In a first example, the method further comprises: derating the high-voltage bus electrical load in response to an engine speed below a threshold speed where the high-voltage bus electrical load exceeds the generating capacity of the engine and motor. In a second example that may include the first example, the method further comprises disconnecting the high-voltage bus electrical load in response to the high-voltage battery state of charge (SOC) being depleted over a plurality of different predetermined threshold time amounts. In a third example that may include one or both of the first and second examples, the method further comprises disconnecting the high-voltage bus electrical load in response to the vehicle's internal combustion engine operating at a predetermined threshold of maximum available engine torque at the current engine speed. In a fourth example that may include one or more of the first to third examples, the method further comprises disconnecting the high-voltage bus electrical load in response to the vehicle's transmission being in park or neutral. In a fifth example that may include one or more of the first to fourth examples, the method further comprises disconnecting the high-voltage bus electrical load in response to a decrease in the high-voltage load threshold. In a sixth example, which may include one or more of the first to fifth examples, the method includes: wherein the high-voltage load is based on a low-voltage bus load and a buffered low-voltage bus load.

[0062] Figure 4 The method also provides a method for operating a vehicle, the method comprising: reducing a high-voltage power consumption threshold in response to a high-voltage battery state of charge (SOC) being less than a target minimum high-voltage battery SOC. In a first example, the method further comprises: reducing the high-voltage power consumption threshold in response to a charging capacity of the internal combustion engine and electric motor being less than the actual total electrical load of the vehicle. In a second example that may include the first example, the method comprises: wherein the total electrical load of the vehicle includes a low-voltage bus electrical load. In a third example that may include one or both of the first and second examples, the method comprises: wherein the total electrical load of the vehicle includes a high-voltage bus electrical load. In a fourth example that may include one or more of the first to third examples, the method comprises: wherein the high-voltage bus electrical load includes a power distribution system supplying power to the outside of the vehicle.

[0063] It should be noted that the example control and estimation routines included herein can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and can be implemented by a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific routines described herein may represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, etc. Therefore, the various actions, operations, and / or functions shown may be performed in the order shown, in parallel, or in some cases omitted. Similarly, the processing order is not necessarily necessary to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the shown actions, operations, and / or functions may be repeatedly performed depending on the specific strategy used. Furthermore, at least a portion of the described actions, operations, and / or functions may be graphically represented as code to be programmed into a non-transitory memory of a computer-readable storage medium in the control system. When the described action is performed by combining instructions from one or more controllers in a system that includes various engine hardware components, the control action can also change the operating state of one or more sensors or actuators in the physical world.

[0064] This specification concludes here. Many variations and modifications will arise in those skilled in the art upon reading this specification without departing from its spirit and scope. For example, this specification may be beneficial to I3, I4, I5, V6, V8, V10, and V12 engines operating with natural gas, gasoline, diesel, or alternative fuels.

[0065] According to the present invention, a method for operating a vehicle includes: disconnecting the high-voltage bus electrical load in response to an engine speed below a threshold speed where the high-voltage bus electrical load exceeds the generating capacity of the engine and motor.

[0066] In one aspect of the invention, the method includes: derated the high-voltage bus electrical load in response to an engine speed below a threshold speed where the high-voltage bus electrical load exceeds the generating capacity of the engine and motor.

[0067] In one aspect of the invention, the method includes: further disconnecting the high-voltage bus electrical load in response to the high-voltage battery SOC being depleted within a plurality of predetermined threshold time amounts.

[0068] In one aspect of the invention, the method includes: further disconnecting the high-voltage bus electrical load in response to the vehicle's internal combustion engine operating at a predetermined threshold of maximum available engine torque at the current engine speed.

[0069] In one aspect of the invention, the method includes: further disconnecting the high-voltage bus electrical load in response to the vehicle's transmission being in park or neutral.

[0070] In one aspect of the invention, the method includes: further disconnecting the high-voltage bus electrical load in response to a decrease in the high-voltage load threshold.

[0071] In one aspect of the invention, the high-voltage load threshold is based on the low-voltage bus load and the buffer low-voltage bus load.

[0072] According to the present invention, a vehicle system is provided, comprising: an internal combustion engine; an electric motor; a traction battery; a high-voltage bus electrically connecting the electric motor to the traction battery; and a controller including executable instructions stored in a non-transitory memory, the executable instructions causing the controller to reduce a high-voltage load threshold in response to the depletion of the state of charge (SOC) of the traction battery over multiple time intervals.

[0073] According to an embodiment, the invention is further characterized by additional executable instructions stored in a non-transitory memory, which cause the controller to reduce the high-voltage load threshold via a proportional / integral (PI) controller.

[0074] According to an embodiment, the high-voltage load threshold is the output of the PI controller, and the minimum target traction battery SOC is the input of the PI controller.

[0075] According to an embodiment, the high-voltage load threshold is an electrical force that can be transmitted via the high-voltage bus.

[0076] According to an embodiment, the high-voltage load threshold is based on the maximum electrical load supported by the internal combustion engine and the electric motor.

[0077] According to an embodiment, the high-voltage load threshold is further based on the low-voltage bus load and the buffer load.

[0078] According to an embodiment, the invention is further characterized by the addition of executable instructions that cause the controller to derating the high-voltage power consumption device electrically connected to the high-voltage bus in response to the high-voltage load threshold.

[0079] According to an embodiment, the invention is further characterized by a transmission coupled to the motor and additional executable instructions, the additional executable instructions causing the controller to reduce the high-voltage load threshold when the transmission is engaged in driving gear.

[0080] According to the present invention, a method for operating a vehicle includes: reducing a high-voltage power consumption threshold in response to a high-voltage battery state of charge (SOC) being less than a target minimum high-voltage battery SOC.

[0081] In one aspect of the invention, the method includes: further reducing the high-voltage power consumption threshold in response to the fact that the charging capacity of the internal combustion engine and the electric motor is less than the actual total electrical load of the vehicle.

[0082] In one aspect of the invention, the actual total electrical load of the vehicle includes a low-voltage bus electrical load.

[0083] In one aspect of the invention, the actual total electrical load of the vehicle includes a high-voltage bus electrical load.

[0084] In one aspect of the invention, the high-voltage bus electrical load includes a power distribution system that supplies power to the outside of the vehicle.

Claims

1. A method for operating a vehicle, comprising: shutting down a high voltage bus electrical load in response to the high voltage bus electrical load exceeding a power generation capacity of an engine and an electric machine for an engine speed below a threshold speed.

2. The method of claim 1, further comprising derating the high voltage bus electrical load in response to the high voltage bus electrical load exceeding the power generation capacity of the engine and the electric machine for the engine speed below the threshold speed.

3. The method of claim 1, further comprising shutting down the high voltage bus electrical load in further response to a high voltage battery SOC being depleted for a plurality of predetermined threshold amounts of time.

4. The method of claim 1, further comprising shutting down the high voltage bus electrical load in further response to an internal combustion engine of the vehicle operating within a predetermined threshold of a maximum available engine torque at a current engine speed.

5. The method of claim 1, further comprising shutting down the high voltage bus electrical load in further response to a transmission of the vehicle being in park or neutral.

6. The method of claim 1, further comprising shutting down the high voltage bus electrical load in further response to a high voltage load threshold being reduced.

7. The method of claim 6, wherein the high voltage load threshold is based on a low voltage bus load and a buffer low voltage bus load.

8. A vehicle system, comprising: an internal combustion engine; an electric machine; a traction battery; a high voltage bus electrically coupling the electric machine with the traction battery; a controller including executable instructions stored in non-transitory memory that cause the controller to reduce a high voltage load threshold in response to a state of charge (SOC) of the traction battery being depleted for a plurality of time intervals.

9. The vehicle system of claim 8, further comprising additional executable instructions stored in non-transitory memory that cause the controller to reduce the high voltage load threshold via a proportional / integral (PI) controller.

10. The vehicle system of claim 9, wherein the high voltage load threshold is an output of the PI controller, and wherein a minimum target traction battery SOC is an input to the PI controller.

11. The vehicle system of claim 8, wherein the high voltage load threshold is an amount of power that can be delivered via the high voltage bus.

12. The vehicle system of claim 11, wherein the high voltage load threshold is based on a maximum electrical load supported via the internal combustion engine and the electric machine.

13. The vehicle system of claim 12, wherein the high voltage load threshold is further based on a low voltage bus load and a buffer load.

14. The vehicle system of claim 8, further comprising additional executable instructions that cause the controller to derate a high voltage power consuming device electrically coupled to the high voltage bus in response to the high voltage load threshold.

15. The vehicle system of claim 14, further comprising a transmission coupled to the electric machine and additional executable instructions that cause the controller to lower the high-voltage load threshold when the transmission is engaged in a drive range.

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