Vehicle-mounted control devices
The in-vehicle control device addresses shocks from torsional torque release by dynamically controlling torque output from an electric motor based on vehicle conditions, ensuring efficient shock suppression.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2023-08-28
- Publication Date
- 2026-05-15
AI Technical Summary
In vehicles with an electric parking brake, sudden release of torsional torque from the drive shaft can cause shocks, and existing methods to mitigate these shocks may inadvertently introduce additional shocks due to uniform damping torque output.
An in-vehicle control device that determines whether to perform shock suppression control based on the vehicle's tilt angle, engagement of the foot brake, and rotational history of the wheels, using an electric motor to output torque accordingly to suppress shocks when the shift lock is released.
Effectively suppresses shocks by selectively applying assist torque from the electric motor, avoiding unnecessary shock suppression control when torsional torque is not present, thereby reducing vibrations and shocks.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to an in-vehicle control device, and more particularly to an in-vehicle control device mounted on a vehicle having an electric parking brake.
Background Art
[0002] Conventionally, as this type of in-vehicle control device, when an idling request is made, the shift lever is in the parking position, and the brake device is off, a process of turning on the brake device is executed, and a process of releasing the lock of the parking mechanism has been proposed (for example, see Patent Document 1). In this device, by such a process, the torsional torque of the drive shaft is released, and the torque transmitted to the engine is released, thereby suppressing the vibration of the vehicle.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In an in-vehicle control device mounted on a vehicle equipped with a motor capable of outputting torque to a drive shaft, if the torsional torque of the drive shaft is suddenly released, a shock will occur. Therefore, a damping torque (assist torque) that mitigates the shock during unlocking is also output from the motor. In this case, if the damping torque is uniformly output from the motor, in some cases, a shock caused by the damping torque will occur.
[0005] The main object of the in-vehicle control device of the present disclosure is to suppress the shock that may occur when the shift lock is released.
Means for Solving the Problems
[0006] The in-vehicle control device of this disclosure employs the following means to achieve the main objective described above.
[0007] The in-vehicle control device disclosed herein is A vehicle control device is mounted on an automobile that includes a shift mechanism having a parking position for shift locking the axle, an electric parking brake for applying braking force to the wheels connected to the axle, and an electric motor capable of inputting and outputting power to the axle, and performs shock suppression control to suppress shocks generated in the vehicle by outputting torque from the electric motor according to the vehicle's tilt angle when the shift lock is released, Depending on the state when the shift lock is engaged and / or after the shift lock is engaged, it is determined whether or not shock suppression control is performed when the shift lock is released. It is characterized by the following:
[0008] The in-vehicle control device of this disclosure is installed in an automobile that includes a shift mechanism having a parking position for shift locking the axle, an electric parking brake that applies braking force to the wheels connected to the axle, and an electric motor capable of inputting and outputting power to the axle. The in-vehicle control device of this disclosure basically performs shock suppression control to suppress shocks generated in the vehicle by outputting torque from the electric motor according to the vehicle's tilt angle when the shift lock is released. The in-vehicle control device of this disclosure determines whether or not to perform shock suppression control when the shift lock is released, depending on the state when the shift lock is locked and / or the state after the shift lock is locked. This makes it possible to suppress shocks caused by performing shock suppression control and to suppress shocks that may occur when the shift lock is released.
[0009] In the in-vehicle control device of this disclosure, when the shift lock is engaged with the foot brake applied and the foot brake is released after the electric parking brake has finished operating, the shock suppression control may not be performed regardless of the vehicle's tilt. When the shift lock is engaged with the foot brake applied and the foot brake is released after the electric parking brake has finished operating, no twisting occurs in the axle, and therefore no torsional torque is generated in the axle. For this reason, there is no need to perform shock suppression control to suppress shocks caused by torsional torque in the axle. This makes it possible to suppress shocks caused by performing shock suppression control.
[0010] In the in-vehicle control device of this disclosure, when the shift lock is released after the shift lock has been applied with the foot brake engaged and there is no rotational history of the wheels, the shock suppression control may not be performed regardless of the vehicle's inclination. When there is no rotational history of the wheels after the shift lock has been applied, no torsion occurs in the axle. Therefore, no torsional torque is generated in the axle. This makes it possible to suppress the shock caused by performing the shock suppression control.
[0011] In the in-vehicle control device of this disclosure, when the shift lock is released after the foot brake has been applied and there is no history of releasing the foot brake, the shock suppression control may not be performed regardless of the vehicle's inclination. When the shift lock is released after the foot brake has been applied and there is no history of releasing the foot brake, the shift lock is performed with the foot brake applied, and then the shift lock is released while the foot brake remains applied. In this case as well, since no twisting occurs in the axle, there is no need to perform the shock suppression control. [Brief explanation of the drawing]
[0012] [Figure 1]This is a schematic diagram showing the configuration of a hybrid vehicle 20 as one embodiment of the present disclosure. [Figure 2] This flowchart shows an example of the shift lock release process performed by the main ECU40. [Figure 3] This is an explanatory diagram showing an example of a parking pattern involving shift lock. [Modes for carrying out the invention]
[0013] Next, embodiments for implementing this disclosure will be described. Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 as one embodiment of this disclosure. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a motor 26, a battery 29, an automatic transmission 30, a brake device 32, and an electronic control unit (hereinafter referred to as "main ECU") 40.
[0014] The engine 22 is configured as an internal combustion engine that outputs power using fuel such as gasoline or diesel from a fuel tank. The crankshaft 23 of this engine 22 is connected to the rotating shaft (rotor) of the motor 26 via a clutch K0. The engine 22 is operated and controlled by an electronic control unit for the engine (hereinafter referred to as "engine ECU") 24.
[0015] The engine ECU 24, although not shown, is a microcomputer that includes a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The engine ECU 24 receives signals from various sensors necessary for controlling the operation of the engine 22, such as the crank angle θcr from a crank position sensor (not shown) that detects the rotational position of the crankshaft 23 of the engine 22, and the coolant temperature Tw from a water temperature sensor (not shown) that detects the temperature of the coolant in the engine 22, via its input ports. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via its output ports. The engine ECU 24 is connected to the main ECU 40 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr of the crankshaft 23 from the crank position sensor.
[0016] The motor 26 is configured, for example, as a synchronous generator-motor, and has a rotor in which permanent magnets are embedded in the rotor core, and a stator in which three-phase coils are wound around the stator core. The rotating shaft to which the rotor of this motor 26 is fixed is connected to the crankshaft 23 of the engine 22 via a clutch K0, and is also connected to the input shaft of the automatic transmission 30. The motor 26 is driven by the switching control of multiple switching elements of the inverter 28 by an electronic motor control unit (hereinafter referred to as "motor ECU") 27, which converts DC power from the battery 29 into three-phase AC power and applies it to the three-phase coils of the motor 26.
[0017] The motor ECU 27, although not shown, is a microcomputer equipped with a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The motor ECU 27 receives signals from various sensors via its input ports, such as the rotational position θm from a rotational position sensor (not shown) that detects the rotational position of the rotor (rotating shaft 31) of the motor 26, and the phase currents Iu and Iv from current sensors that detect the phase currents of each phase of the motor 26. The motor ECU 27 outputs control signals to the inverter 28 via its output ports. The motor ECU 27 is connected to the main ECU 40 via a communication port. The motor ECU 27 calculates the rotational speed Nm of the motor 26 based on the rotational position θm of the rotor (rotating shaft) of the motor 26 from the rotational position sensor.
[0018] Clutch K0 is configured, for example, as a hydraulically driven friction clutch, controlled by the main HVECU 40, and connects and disconnects the crankshaft 23 of the engine 22 from the rotating shaft of the motor 26.
[0019] The automatic transmission 30 includes a torque converter and a stepped (e.g., 6-speed) automatic transmission. The torque converter is configured as a general fluid transmission device and transmits power from the input shaft connected to the rotating shaft of the motor 26 to the input shaft of the automatic transmission with amplified torque, or transmits the torque directly without amplification. The automatic transmission transmits power between its input shaft and the axle 36, which acts as the output shaft, by engaging and disengaging multiple friction engagement elements to form forward and reverse gears from the 1st to the Nth gear, as well as a shift lock. The clutch K0 and the automatic transmission are supplied with hydraulic fluid from a mechanical oil pump or an electric oil pump, with the hydraulic pressure regulated by a hydraulic control device (not shown). The hydraulic control device includes a valve body with multiple oil passages, multiple regulator valves, multiple linear solenoid valves, etc. This hydraulic control device is controlled by the main ECU 40. The main ECU 40 changes the gear of the automatic transmission by applying the accelerator opening Acc and the vehicle speed V to a gear shift diagram (not shown).
[0020] The braking device 32 is configured as a well-known hydraulically driven braking device, and is configured to be able to apply a braking force caused by a braking pedal force when the brake pedal 58 is depressed or a braking force caused by hydraulic pressure adjustment to the wheels 38a, 38b and the wheels 38c, 38d. The braking device 32 is driven and controlled by an electronic control unit for braking (hereinafter referred to as "brake ECU") 33. The brake ECU 33 includes, although not shown, a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. The brake ECU 33 controls a braking force caused by a braking pedal force by the braking device 32 and a braking force caused by hydraulic pressure adjustment. The brake ECU 33 communicates with the main ECU 40 via a communication port.
[0021] The main ECU 40 includes a microcomputer having a CPU 41, a ROM 42, a RAM 43, a flash memory 44, input / output ports and communication ports not shown. Signals from various sensors are input to the main ECU 40 via the input ports. Examples of the signals input to the main ECU 40 include an ignition signal from an ignition switch 50, a shift position SP from a shift position sensor 52 that detects the position of a shift lever 51, an accelerator opening Acc from an accelerator pedal position sensor 54 that detects the depression amount of an accelerator pedal 53, and a brake pedal position BP from a brake pedal position sensor 56 that detects the depression amount of a brake pedal 55. Also, the vehicle speed V from a vehicle speed sensor 51, the wheel speeds of each wheel from a wheel speed sensor 52, and the road surface gradient θr from a gradient sensor 55 can be mentioned. Furthermore, an EPBSW signal from an electric parking brake switch (hereinafter referred to as "EPB switch") 60, signals from sensors that detect various states of a clutch K0 and a hydraulic control device of an automatic transmission 30, etc. can also be mentioned. The electric parking brake is configured such that a brake device 32 is driven and controlled by a brake ECU 33 to apply a braking force to wheels 38a, 38b, and it operates when the EPB switch 60 is turned on, and is released when the EPB switch 60 is turned off or the shift lock is released.
[0022] Various control signals are output from the main ECU 40 via the output ports. Examples of the control signals output from the main ECU 40 include a control signal to a hydraulic control device, a display control signal to a display device 70, etc. As described above, the main ECU 40 communicates with an engine ECU 24, a motor ECU 27, a brake ECU 33, etc. via the communication ports.
[0023] Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when releasing the shift lock, will be described. Figure 2 is a flowchart showing an example of the shift lock release process performed by the main ECU 40, and Figure 3 is an explanatory diagram showing an example of a parking pattern with shift lock. For ease of explanation, the parking pattern with shift lock will first be explained using Figure 3, and then the operation when releasing the shift lock will be explained using Figure 2.
[0024] In all parking patterns, the driver first applies the foot brake by pressing the brake pedal 55 to stop the vehicle, and then, with the brake pedal 55 pressed, moves the shift lever 51 to the P position (parking position) to engage the shift lock. Pattern (A) is a pattern in which, from this common state (shift locked and the driver pressing the brake pedal 55), the shift lever 51 is moved to the R position (reverse position), N position (neutral position), or D position (forward position) to release the shift lock without engaging the electric parking brake. Pattern B is a pattern in which, from the common state, the driver releases the brake pedal 55 to release the foot brake, and then the shift lock is released without engaging the electric parking brake. Pattern (C) is a pattern in which, from the common state, the electric parking brake is engaged, then the driver releases the brake pedal 55 to release the foot brake, and then the shift lock is released. Pattern (D) is a pattern in which, starting from a common state, the driver releases the brake pedal 55 to release the foot brake, then the electric parking brake is activated, and subsequently the shift lock is released.
[0025] In the shift lock release process shown in Figure 2, it is first determined whether the shift position SP is in the P position (parking position) (step S100), and then it is determined whether the shift position SP has been changed from the P position to the R position, N position, D position, etc., and the shift lock has been released (step S110). If it is determined in step S100 that the shift position SP is not in the P position, or if it is determined in step S110 that the shift lock has not been released, it is determined that this process is not applicable, and the process returns to step S10.
[0026] In steps S100 and S110, when it is determined that the shift position SP has been changed from the P position to the R position, N position, D position, etc., and the shift lock has been released, an assist torque for vibration damping to reduce the shock during shift lock is determined based on the vehicle's tilt angle θ, which is obtained using the road surface gradient θr from the gradient sensor 59 (step S120). The assist torque is used as an out-of-phase torque to counteract the torsional torque of the axle 36, which increases as the vehicle's tilt angle θ increases. For example, the relationship between the vehicle's tilt angle θ and the assist torque can be determined in advance by experimentation or machine learning and stored as an assist torque setting map. When the vehicle's tilt angle θ is given, the corresponding assist torque can be derived from the assist torque setting map to determine the assist torque.
[0027] Next, it is determined whether the foot brake was released after the electric parking brake had completed its operation (step S130). This determination is made to determine whether the situation is pattern (C) in the parking patterns shown in Figure 3. If it is determined that the situation is pattern (C), in which the foot brake was released after the electric parking brake had completed its operation, the process is terminated without performing shock suppression control, which involves outputting assist torque from the motor 26 when the shift lock is released (step S170). In this pattern (C), since the foot brake is released after the electric parking brake has completed its operation following the shift lock, no torsional torque is generated in the axle 36, and therefore there is no need to perform shock suppression control.
[0028] If it is determined in step S130 that the electric parking brake has completed operation and the foot brake has not been released, it is determined in step S140 whether or not there is a rotation history for the wheels 38a and 38b after the shift lock. The rotation history for the wheels 38a and 38b can be determined by whether or not wheel speed has been generated for the wheels 38a and 38b by the wheel speed sensor 57 after the shift lock. If it is determined that there is no rotation history for the wheels 38a and 38b after the shift lock, this process is terminated without performing shock suppression control (step S170). Torsional torque on the axle 36 is generated when the wheels 38a and 38b rotate after the shift lock, so if there is no rotation history for the wheels 38a and 38b after the shift lock, no torsional torque is generated on the axle 36, and therefore there is no need to perform shock suppression control. This corresponds to patterns (A) and (C) in the parking patterns in Figure 3.
[0029] Next, it is determined whether or not there is a history of the foot brake being released after the shift lock (step S150). If it is determined that there is no history of the foot brake being released after the shift lock, the process is terminated without performing shock suppression control (step S170). When there is no history of the foot brake being released after the shift lock, it is equivalent to saying that there is no rotation history of the wheels 38a and 38b after the shift lock, so no torsional torque is generated in the axle 36. For this reason, there is no need to perform shock suppression control. This corresponds to pattern (A) in the parking pattern in Figure 3.
[0030] If all of the judgments in steps S130 to S150 are negative, it is determined that torsional torque is being generated in the axle 36, and shock suppression control is executed by outputting assist torque from the motor 26 when the shift lock is released (step S160), and this process is terminated.
[0031] In the hybrid vehicle 20 of the embodiment described above, when the electric parking brake has completed operation before the foot brake is released when the vehicle is stopped and the shift lock is engaged, the shock suppression control that outputs assist torque from the motor 26 when the shift lock is released is not performed. This makes it possible to suppress vibrations and shocks caused by performing shock suppression control even though no torsional torque is generated in the axle 36.
[0032] Furthermore, in the hybrid vehicle 20 of this embodiment, if there is no rotational history of the wheels 38a and 38b after the vehicle has stopped and the shift lock has been engaged, the shock suppression control that outputs assist torque from the motor 26 when the shift lock is released is not performed. This makes it possible to suppress vibrations and shocks caused by performing shock suppression control even though no torsional torque is generated in the axle 36.
[0033] Furthermore, in the hybrid vehicle 20 of this embodiment, if there is no history of releasing the foot brake after the vehicle has stopped and the shift lock has been locked, the shock suppression control that outputs assist torque from the motor 26 when the shift lock is released is not performed. This makes it possible to suppress vibrations and shocks caused by performing shock suppression control even though no torsional torque is generated in the axle 36.
[0034] In the embodiment of the hybrid vehicle 20, a stepped automatic transmission 30 is provided, but the automatic transmission 30 may be a continuously variable transmission.
[0035] In the hybrid vehicle 20 of this embodiment, the motor 26 and automatic transmission 30 are connected to the crankshaft 23 of the engine 22 via a clutch K0. However, the motor 26 and automatic transmission 30 may be connected to the crankshaft 23 of the engine 22 without using the clutch K0. In addition to the configuration in which the motor 26 and automatic transmission 30 are connected to the crankshaft 23 of the engine 22 via a clutch K0, a second motor may be attached to the axle connected to the wheels 38c and 38d. Alternatively, instead of the motor 26, an in-wheel motor directly attached to the wheels 38a and 38b may be provided. In other words, any configuration is acceptable as long as the vehicle is equipped with a shift mechanism, an electric parking brake, and an electric motor.
[0036] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In the embodiment, the shift lever 51 and the automatic transmission 30 correspond to the "shift mechanism", the electric parking brake switch 60 and the brake device 32 correspond to the "electric parking brake", the motor 26 corresponds to the "electric motor", the hybrid vehicle 20 corresponds to the "vehicle", and the main electronic control unit 40, the motor electronic control unit 27 and the brake electronic control unit 33 correspond to the "vehicle control device".
[0037] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.
[0038] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and can be carried out in various forms without departing from the spirit of the present invention. [Industrial applicability]
[0039] This invention can be used in industries such as automobile manufacturing. [Explanation of Symbols]
[0040] 20 Hybrid vehicle, 22 Engine, 23 Crankshaft, 24 Engine electronic control unit (Engine ECU), 32 Brake system, 33 Brake electronic control unit (Brake ECU), 36 Axle, 37 Differential gear, 38a, 38b Wheels, 38c, 38d Wheels, 40 Main electronic control unit (Main ECU), 41 CPU, 42 ROM, 43 RAM, 44 Flash memory, 50 Ignition switch, 51 Shift lever, 52 Shift position sensor, 53 Accelerator pedal, 54 Accelerator pedal position sensor, 55 Brake pedal, 56 Brake pedal position sensor, 57 Vehicle speed sensor, 58 Wheel speed sensor, 59 Gradient sensor, 60 Electric parking brake switch (EPB switch), 70 Display device.
Claims
1. A vehicle control device is mounted on an automobile that includes a shift mechanism having a parking position for shift locking the axle, an electric parking brake for applying braking force to the wheels connected to the axle, and an electric motor capable of inputting and outputting power to the axle, and performs shock suppression control to suppress shocks generated in the vehicle by outputting torque from the electric motor according to the vehicle's tilt angle when the shift lock is released, When the shift lock is engaged while the foot brake is applied, and then released after the electric parking brake has finished operating, the shock suppression control will not be performed regardless of the vehicle's inclination. An in-vehicle control device characterized by the following features.
2. A vehicle control device is mounted on an automobile that includes a shift mechanism having a parking position for shift locking the axle, an electric parking brake for applying braking force to the wheels connected to the axle, and an electric motor capable of inputting and outputting power to the axle, and performs shock suppression control to suppress shocks generated in the vehicle by outputting torque from the electric motor according to the vehicle's tilt angle when the shift lock is released, When the shift lock is released after the foot brake has been applied and there is no history of releasing the foot brake, the shock suppression control will not be executed regardless of the vehicle's inclination. An in-vehicle control device characterized by the following features.