Vehicle control device

Abstract

To provide a control device for a vehicle that is able to accurately determine downhill movement of the vehicle even when a garage shift is executed.SOLUTION: An HCU determines whether a garage shift, which is an operation of changing a shift position from one of a forward range and a reverse range to the other, has been performed by a driver or not (step S1). When it is determined that the garage shift has been performed, the HCU performs a first downhill movement determination process to determine whether a vehicle is moving downhill or not (step S2). When it is determined that the garage shift has not been executed, the HCU performs a second downhill movement determination process different from the first sliding-down determination process to determine whether the vehicle is moving downhill or not (step S3). In a case where it is determined that there is a downhill movement of the vehicle by the first downhill movement determination process or the second downhill movement determination process (YES in step S4), the HCU increases a driving force of the vehicle 1 (step S5).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Patent Document 1 describes a technology in which, when the vehicle is traveling uphill using a motor, the vehicle speed is compared with a threshold speed, which is a negative value, and if the vehicle speed is equal to or less than the threshold speed, it is determined that the vehicle is rolling downhill and the engine is started. The technology described in Patent Document 1 can stop the vehicle from rolling downhill by compensating for the shortage of motor torque with engine torque. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-84453 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the system described in Patent Document 1 determines that the vehicle is rolling over when it detects a vehicle speed in the opposite direction to the direction of travel based on the shift position. Therefore, when the driver performs a garage shift, which is an operation to change the shift position from one of the forward range or reverse range to the other, there is a risk that the system will erroneously determine that the vehicle is rolling over even though it is not actually rolling over.

[0005] For example, if the driver switches the shift position from reverse to forward while the vehicle is moving backward at a slow speed, the vehicle is still moving backward immediately after switching to forward range, which can result in an erroneous determination that the vehicle is rolling backward.

[0006] Therefore, an object of the present invention is to provide a vehicle control device that can accurately determine whether the vehicle is sliding downhill even when a garage shift is performed. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a control device for a vehicle that has at least a motor as a driving force source that transmits power to driving wheels, and is characterized by comprising: a garage shift determination unit that determines whether a garage shift, which is an operation of changing the shift position from one of a forward range or a reverse range to the other, has been performed by the driver while the vehicle is traveling using the driving force generated by the motor; a first rollover determination unit that, if it is determined by the garage shift determination unit that the garage shift has been performed, performs a first rollover determination process to determine whether the vehicle has rolled over; a second rollover determination unit that, if it is determined by the garage shift determination unit that the garage shift has not been performed, performs a second rollover determination process different from the first rollover determination process to determine whether the vehicle has rolled over; and a control unit that increases the driving force of the vehicle if it is determined by the first rollover determination process or the second rollover determination process that the vehicle is rolling over. [Effects of the Invention]

[0008] Thus, according to the present invention, it is possible to provide a vehicle control device that can accurately determine whether the vehicle is sliding downhill even when a garage shift is performed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an overview of a vehicle control device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the procedure of the vehicle skid determination operation performed by the vehicle control device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing a procedure for carrying out the first skid determination process by the vehicle control device according to one embodiment of the present invention based on the shift position, motor rotation speed, and motor rotation acceleration. [Figure 5] FIG. 5 is a flowchart showing the procedure for carrying out the second skid determination process based on the shift position and the motor rotation speed by the vehicle control device according to one embodiment of the present invention. [Figure 6] FIG. 6 is a flowchart showing a procedure for carrying out the first skid determination process by the vehicle control device according to one embodiment of the present invention based on the shift position, vehicle speed, and vehicle acceleration. [Figure 7] FIG. 7 is a flowchart showing the procedure for carrying out the second skid determination process based on the shift position and the vehicle speed by the vehicle control device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle control device according to one embodiment of the present invention is a control device for a vehicle that has at least a motor as a driving force source that transmits power to drive wheels, and is characterized by including: a garage shift determination unit that determines whether a garage shift, which is an operation to change the shift position from one of a forward range or a reverse range to the other, has been performed by the driver while the vehicle is traveling using driving force generated by the motor; a first rollover determination unit that, if the garage shift determination unit determines that a garage shift has been performed, performs a first rollover determination process to determine whether the vehicle is rolling over; a second rollover determination unit that, if the garage shift determination unit determines that a garage shift has not been performed, performs a second rollover determination process different from the first rollover determination process to determine whether the vehicle is rolling over; and a control unit that, if it is determined by the first rollover determination process or the second rollover determination process that the vehicle is rolling over, increases the driving force of the vehicle. As a result, the vehicle control device according to one embodiment of the present invention can accurately determine whether the vehicle is rolling over even if a garage shift has been performed. [Example]

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle equipped with a control device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] In FIG. 1, a vehicle 1 according to one embodiment of the present invention includes an engine 2 as an internal combustion engine, a transmission 3 as an automatic transmission, a motor generator 4 as a motor, drive wheels 5, an HCU (Hybrid Control Unit) 10 as a control unit that comprehensively controls the vehicle 1, an ECM (Engine Control Module) 11 that controls the engine 2, a TCM (Transmission Control Module) 12 that controls the transmission 3, an ISGCM (Integrated Starter Generator Control Module) 13, an INVCM (Inverter Control Module) 14, and a BMS (Battery Management System) 16.

[0013] The engine 2 is formed with a plurality of cylinders. In this embodiment, the engine 2 is configured to perform a series of four strokes for each cylinder, including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.

[0014] An ISG (Integrated Starter Generator) 20 and a starter 21 are connected to the engine 2. The ISG 20 is connected to a crankshaft 18 of the engine 2 via a belt 22 or the like. The ISG 20 functions as an electric motor that rotates when supplied with electric power, thereby driving the engine 2 to rotate, and also functions as a generator that converts the rotational force input from the crankshaft 18 into electric power.

[0015] In this embodiment, the ISG 20 functions as an electric motor under the control of the ISGCM 13, thereby restarting the engine 2 from a stopped state caused by the idling stop function. The ISG 20 can also assist the vehicle 1 in traveling by functioning as an electric motor.

[0016] The starter 21 includes a motor and a pinion gear (not shown). The starter 21 rotates the motor to rotate the crankshaft 18, thereby providing the rotational force for starting the engine 2. In this manner, the engine 2 is started by the starter 21 and is restarted by the ISG 20 from a stopped state due to the idling stop function.

[0017] The transmission 3 changes the speed of the rotation output from the engine 2 and drives the drive wheels 5 via a drive shaft 23. The transmission 3 includes a constant mesh type speed change mechanism 25 made up of a parallel shaft gear mechanism, a clutch 26 as a power transmission mechanism made up of a normally closed type dry clutch, a differential mechanism 27, and an actuator (not shown).

[0018] The transmission 3 is configured as a so-called AMT (Automated Manual Transmission), and an actuator controlled by the TCM 12 switches the gear position in the speed change mechanism 25 and engages and disengages the clutch 26. The differential mechanism 27 transmits the power output by the speed change mechanism 25 to the drive shaft 23.

[0019] The motor generator 4 is connected to a differential mechanism 27 via a chain 28. The motor generator 4 functions as an electric motor.

[0020] The motor generator 4 also functions as a generator, generating electricity by running the vehicle 1. The motor generator 4 need only be connected to any point in the power transmission path from the engine 2 to the drive wheels 5 so as to be capable of transmitting power, and does not necessarily have to be connected to the differential mechanism 27.

[0021] In this way, vehicle 1 is equipped with engine 2 and motor generator 4 as driving power sources that transmit power to drive wheels 5, and is a hybrid vehicle that can run using at least one of the engine torque of engine 2 or the motor torque of motor generator 4.

[0022] Here, the driving modes of the vehicle 1 include an HEV driving mode and an EV driving mode.

[0023] The HEV driving mode is a mode in which the vehicle 1 runs using the engine torque of the engine 2 and the motor torque of the motor generator 4. In the HEV driving mode, the HCU 10 stops, starts, and controls the torque of the engine 2 and controls the torque of the motor generator 4 in accordance with the driver's requested torque and the like.

[0024] The EV driving mode is a mode in which the vehicle 1 travels solely by the motor torque of the motor generator 4. In the EV driving mode, the vehicle 1 does not use the engine 2 and therefore corresponds to a so-called electric vehicle that has only a motor as a driving force source.

[0025] The vehicle 1 also has an engine driving mode, which is a driving mode in which the vehicle 1 runs using only the engine torque of the engine 2 when the motor generator 4 cannot be used for some reason. In the engine driving mode, the vehicle 1 does not use the motor generator 4, and therefore corresponds to a so-called conventional vehicle that has only the engine as a driving force source.

[0026] The vehicle 1 includes a first power storage device 30, a high-voltage power pack 34 including a second power storage device 33 as a power storage unit, a high-voltage cable 35, and a low-voltage cable 36.

[0027] The first power storage device 30 and the second power storage device 33 are configured by rechargeable secondary batteries. The first power storage device 30 is configured by a lead battery.

[0028] The first power storage device 30 is a low-voltage battery in which the number of cells and other factors are set so as to generate an output voltage of approximately 12 V. The state of the first power storage device 30, such as the remaining capacity, temperature, and charge / discharge current, is managed by the HCU 10.

[0029] The second power storage device 33 is a high-voltage battery in which the number of cells and the like are set so as to generate a higher voltage than the first power storage device 30, and generates an output voltage of, for example, 100 V. The second power storage device 33 is formed, for example, of a lithium-ion battery. The state of the second power storage device 33, such as the amount of stored power, temperature, and charge / discharge current, is managed by the BMS 16.

[0030] The vehicle 1 is provided with a general load 37 as an electrical load. The general load 37 is an electrical load other than the starter 21 and the ISG 20.

[0031] The general loads 37 are electrical loads that do not require a stable power supply and are used temporarily. The general loads 37 include, for example, windshield wipers (not shown) and an electric cooling fan that blows cooling air to the engine 2.

[0032] The first power storage device 30 is connected via a low-voltage cable 36 to the starter 21, the ISG 20, and a general load 37 as an electrical load so as to be able to supply electric power thereto.

[0033] In this way, the first power storage device 30 is configured to supply at least electric power to the starter 21 and the ISG 20, which serve as starting devices for starting the engine 2.

[0034] The high-voltage power pack 34 has an inverter 45, an INVCM 14, and a BMS 16 in addition to the second power storage device 33. The high-voltage power pack 34 is connected to the motor generator 4 via a high-voltage cable 35 so as to be able to supply electric power to the motor generator 4.

[0035] Under the control of INVCM 14, inverter 45 converts AC power applied to high-voltage cable 35 into DC power applied to second power storage device 33, and vice versa. For example, when INVCM 14 powers motor generator 4, INVCM 14 converts DC power discharged from second power storage device 33 into AC power using inverter 45 and supplies the AC power to motor generator 4.

[0036] When the motor generator 4 is used for regeneration, the INVCM 14 converts the AC power generated by the motor generator 4 into DC power using the inverter 45 and charges the second power storage device 33 with the DC power.

[0037] HCU10, ECM11, TCM12, ISGCM13, INVCM14 and BMS16 are each composed of a computer unit equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory for storing backup data, etc., input ports and output ports.

[0038] The ROMs of these computer units store various constants, various maps, and the like, as well as programs for causing the computer units to function as the HCU 10, ECM 11, TCM 12, ISGCM 13, INVCM 14, and BMS 16, respectively.

[0039] That is, the CPU executes the programs stored in the ROM using the RAM as a work area, and these computer units function as the HCU 10, ECM 11, TCM 12, ISGCM 13, INVCM 14, and BMS 16 in this embodiment, respectively.

[0040] In this embodiment, the ECM 11 executes idling stop control. In this idling stop control, the ECM 11 stops the engine 2 when a predetermined stop condition is met, and restarts the engine 2 by driving the ISG 20 via the ISGCM 13 when a predetermined restart condition is met. This prevents unnecessary idling of the engine 2, thereby improving the fuel efficiency of the vehicle 1.

[0041] The vehicle 1 is provided with CAN (Controller Area Network) communication lines 48 and 49 for forming an in-vehicle LAN (Local Area Network) that conforms to standards such as CAN.

[0042] The HCU 10 is connected to the INVCM 14 and the BMS 16 by a CAN communication line 48. The HCU 10, the INVCM 14, and the BMS 16 mutually transmit and receive signals such as control signals via the CAN communication line 48.

[0043] The HCU 10 is connected to the ECM 11, the TCM 12, and the ISGCM 13 via a CAN communication line 49. The HCU 10, the ECM 11, the TCM 12, and the ISGCM 13 mutually transmit and receive signals such as control signals via the CAN communication line 49.

[0044] In FIG. 2, various sensors such as a shift position sensor 51, a motor rotation speed sensor 52, and a vehicle speed sensor 53 are connected to the input port of the HCU 10.

[0045] The shift position sensor 51 detects the position of a shift lever (not shown) operated by the driver (hereinafter also referred to as the shift position), and outputs a detection signal to the HCU 10. The shift positions include a forward range for moving the vehicle 1 forward and a reverse range for moving the vehicle 1 backward. The forward range is generally called the D range, and the reverse range is called the R range. In addition to the D range, in which the gear stage is automatically changed, the forward range also includes an M range in which the gear stage is changed by the driver, an L range in which the gear stage is limited to a low gear, and the like.

[0046] The motor rotation speed sensor 52 detects the rotation speed of the motor generator 4 (hereinafter also referred to as the motor rotation speed), and outputs a detection signal to the HCU 10. As the motor rotation speed sensor 52, a resolver can be used.

[0047] The resolver used in the motor rotation speed sensor 52 is a sensor that can detect the rotation angle (rotation position), rotation speed, and rotation direction of the motor generator 4 with high accuracy. While the resolver can detect with high accuracy, the output signal can sometimes change suddenly (large changes in a short period of time) due to factors such as gear backlash. For this reason, the output signal that is changing suddenly is not used to determine whether the vehicle 1 is skidding.

[0048] Vehicle speed sensor 53 detects the speed of vehicle 1 (hereinafter also referred to as vehicle speed or vehicle speed) and outputs a detection signal to HCU 10. Vehicle speed sensor 53 detects the speed and traveling direction of vehicle 1 based on the rotation speed and rotation direction of drive wheels 5. In this embodiment, since motor generator 4 is connected to drive wheels 5 via differential mechanism 27, vehicle speed may be calculated based on the motor rotation speed.

[0049] Here, when the driving torque in the uphill direction on an uphill road is smaller than the torque required for climbing the slope, the vehicle 1 may roll backward (slide down) in the downhill direction.

[0050] When the vehicle 1 rolls downhill on an uphill road, the shift position is in the forward range, but the vehicle speed and the rotation direction of the motor generator 4 are values ​​that cause the vehicle 1 to move backward. Note that the vehicle 1 may also roll downhill when the vehicle 1 moves downhill while backing uphill.

[0051] Therefore, when traveling uphill, if the HCU 10 detects that the vehicle speed or the rotational speed of the motor generator 4 is in the opposite direction (the sign is reversed) to the direction of travel based on the shift position, it can determine that the vehicle 1 is sliding downhill.

[0052] On the other hand, the vehicle 1 may roll back not only when traveling uphill, but also when parking the vehicle 1 in an inclined parking position or in a garage. Generally, when parking the vehicle 1, the driver performs a garage shift, which is an operation of changing (shifting) the shift position from one of the forward range or reverse range to the other.

[0053] Such a garage shift is usually performed after the vehicle 1 has come to a complete stop, but can also be performed while the vehicle 1 is traveling at a very slow speed (for example, less than 10 km / h) before coming to a complete stop. Therefore, a garage shift may be performed from the reverse range to the forward range while the vehicle 1 is moving backward at a very slow speed, or from the forward range to the reverse range while the vehicle 1 is moving forward at a very slow speed.

[0054] If the determination of whether vehicle 1 is sliding down is based solely on the vehicle speed or the rotational speed of motor generator 4, in a situation where a garage shift is performed by the driver, there is a risk that it may be erroneously determined that vehicle 1 is sliding down even though in fact vehicle 1 is not sliding down.

[0055] For example, when a driver parks vehicle 1, if the driver switches the shift position from reverse range to forward range while vehicle 1 is reversing slowly, vehicle 1 is still reversing immediately after switching from reverse range to forward range, and therefore it may be erroneously determined that vehicle 1 is sliding downhill even if the reversing of vehicle 1 is not due to a slope of the road surface.

[0056] Therefore, in this embodiment, when a garage shift is performed, the HCU 10 determines whether or not the vehicle 1 is sliding downhill using a method different from that when a garage shift is not performed.

[0057] Specifically, when a garage shift is not being performed, the HCU 10 determines whether the vehicle 1 is skidding based on the vehicle speed or the motor rotation speed. On the other hand, when a garage shift is being performed, the HCU 10 determines whether the vehicle 1 is skidding based on the acceleration of the vehicle 1 (hereinafter also referred to as vehicle acceleration) or the acceleration of the motor generator 4 (hereinafter also referred to as motor rotation acceleration) in addition to the vehicle speed or the motor rotation speed. The vehicle speed and the motor rotation speed increase in the downhill direction when the vehicle 1 is actually skidding, but decrease when a garage shift is performed while the vehicle is traveling at a very slow speed. When a garage shift is being performed, the HCU 10 can accurately determine whether the vehicle 1 is skidding by also referring to the vehicle acceleration or the motor rotation acceleration. The HCU 10 calculates the vehicle acceleration by differentiating the vehicle speed and calculates the motor rotation acceleration by differentiating the motor rotation speed. Furthermore, the HCU 10 increases the driving force of the vehicle 1 when it is determined that the vehicle 1 is skidding.

[0058] The following describes the vehicle skidding determination operation executed by the HCU 10. This vehicle skidding determination operation determines whether or not the vehicle 1 is skidding, and if it is determined that skidding is occurring, increases the driving force of the vehicle 1. In this embodiment, the vehicle speed and motor rotation speed in the forward direction of the vehicle 1 are set to positive values, and the vehicle speed and motor rotation speed in the reverse direction of the vehicle 1 are set to negative values.

[0059] First, a description will be given of a vehicle skid determination operation that is performed while the vehicle is traveling using motor torque in the HEV traveling mode or while the vehicle is traveling in the EV traveling mode. The skid determination operation described below can also be applied to electric vehicles.

[0060] The HCU 10 determines whether or not a garage shift, which is an operation for changing the shift position from one of the forward range or the reverse range to the other, has been performed by the driver while the vehicle is running using the driving force generated by the motor generator 4.

[0061] Next, when the HCU 10 determines that a garage shift has been performed, it performs a first skid determination process to determine whether or not the vehicle 1 has skidded. When the HCU 10 determines that a garage shift has not been performed, it performs a second skid determination process different from the first skid determination process to determine whether or not the vehicle 1 has skidded.

[0062] Then, when it is determined by the first skid determination process or the second skid determination process that the vehicle 1 is skidding, the HCU 10 increases the driving force of the vehicle 1. Here, "increasing the driving force of the vehicle 1" means increasing the motor torque while the vehicle is running using the motor torque in the EV driving mode, and in the HEV driving mode, increasing the motor torque or starting the engine 2 to increase the engine torque. In other words, "increasing the driving force of the vehicle 1" means increasing the driving force available in the current driving mode or vehicle configuration.

[0063] The first skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position, the rotation speed of the motor generator 4, and the rotation acceleration of the motor generator 4.

[0064] The second skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position and the rotation speed of the motor generator 4.

[0065] The first skid determination process is preferably a process for determining whether or not the vehicle 1 is skidding based on whether the absolute value of the rotational acceleration of the motor generator 4 is smaller than a predetermined threshold value, and based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4. In this embodiment, in order to eliminate the influence of gear backlash, the HCU 10 determines whether or not the vehicle 1 is skidding based on the shift position, the rotational speed, and the rotational acceleration of the motor generator 4 only if the absolute value of the rotational acceleration of the motor generator 4 is smaller than a predetermined threshold value.

[0066] The first skid determination process may be a process for determining whether or not the vehicle 1 is skidding based on the shift position, the speed of the vehicle 1, and the acceleration of the vehicle 1.

[0067] The second skid determination process may be a process for determining whether the vehicle 1 is skidding based on the shift position and the speed of the vehicle 1.

[0068] When the vehicle is traveling using motor torque in HEV driving mode, if the first skid determination process or the second skid determination process determines that the vehicle 1 is skidding, the HCU 10 may start the engine 2 to increase the driving force of the vehicle 1.

[0069] Next, a description will be given of a vehicle skid determination operation that is performed while the vehicle is running using engine torque in the HEV driving mode or while the vehicle is running in the engine driving mode. The following skid determination operation can also be applied to conventional vehicles.

[0070] The HCU 10 determines whether or not a garage shift, which changes the shift position from one of the forward range or the reverse range to the other, has been performed by the driver while the vehicle is running using the driving force generated by the engine 2.

[0071] Next, when it is determined that a garage shift has been performed, the HCU 10 performs a first skid determination process to determine whether or not the vehicle 1 has skidded. When it is determined that a garage shift has not been performed, the HCU 10 performs a second skid determination process different from the first skid determination process to determine whether or not the vehicle 1 has skidded.

[0072] Then, the HCU 10 increases the driving force of the vehicle 1 when it is determined by the first skid determination process or the second skid determination process that the vehicle 1 is skidding.

[0073] Here, "increasing the driving force of vehicle 1" means increasing the engine torque or increasing the motor torque when the vehicle is running using engine torque in HEV driving mode, and increasing the engine torque in engine driving mode. In other words, "increasing the driving force of vehicle 1" means increasing the driving force available in the current driving mode or vehicle configuration.

[0074] The first skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position, the speed of the vehicle 1, and the acceleration of the vehicle 1.

[0075] The second skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position and the speed of the vehicle 1.

[0076] In this way, the HCU 10 constitutes the garage shift determination unit, the first skid determination unit, the second skid determination unit, and the control unit of the present invention. The HCU 10 also constitutes a motor acceleration calculation unit that calculates the rotational acceleration of the motor generator 4, and a vehicle acceleration calculation unit that calculates the acceleration of the vehicle 1.

[0077] The flow of the vehicle skid determination operation performed by the control device according to this embodiment will be described with reference to Fig. 3. The vehicle skid determination operation starts when the HCU 10 starts operation, and is executed at preset time intervals.

[0078] In step S1, the HCU 10 determines whether or not a garage shift has been performed.

[0079] If the HCU10 determines that a garage shift has been performed, it performs a first skid determination process in step S2, and if it determines that a garage shift has not been performed, it performs a second skid determination process in step S3.

[0080] Therefore, in a situation where the vehicle 1 is traveling uphill in forward range, the second skid determination process determines whether the vehicle 1 is skidding, and in a situation where the vehicle 1 is being parked with a garage shift, the first skid determination process determines whether the vehicle 1 is skidding.

[0081] The first skidding determination process is performed during a period from when the execution of a garage shift is detected until a predetermined time (for example, 2 seconds) has elapsed, or during a period from when the execution of a garage shift is detected until the driving direction corresponding to the range is detected. The period from when the execution of a garage shift is detected until the driving direction corresponding to the range is detected is specifically the period from when a shift from the reverse range to the forward range is detected until driving in the forward direction is detected. Alternatively, it is the period from when a shift from the forward range to the reverse range is detected until driving in the reverse direction is detected.

[0082] The HCU 10 determines whether or not the vehicle 1 is sliding down by using different methods in the first sliding down determination process (step S2) or the second sliding down determination process (step S3). Details of the flow of the first sliding down determination process and the second sliding down determination process will be described with reference to Figures 4 and 5, or Figures 6 and 7.

[0083] After executing step S2 or step S3, the HCU 10 determines in step S4 whether or not the vehicle 1 is rolling down. In this step S4, the HCU 10 determines whether or not it has been determined in the first rolling down determination process (step S2) or the second rolling down determination process (step S3) that the vehicle 1 is rolling down. If the HCU 10 determines in step S4 that the vehicle 1 is not rolling down, it ends the current operation.

[0084] If it is determined in step S4 that the vehicle 1 is sliding downhill, the HCU 10 increases the driving force of the vehicle 1 in step S5.

[0085] The flow of the first skid determination process and the second skid determination process that are performed while the vehicle is running using motor torque in the HEV driving mode or while the vehicle is running in the EV driving mode will be described with reference to FIGS.

[0086] The first skid determination process in step S2 of FIG. 3 will be described in detail with reference to FIG.

[0087] In step S11, the HCU 10 calculates the motor rotation acceleration. Next, in step S12, the HCU 10 determines whether the absolute value of the motor rotation acceleration is smaller than a predetermined threshold value α.

[0088] If the HCU 10 determines that the absolute value of the motor rotation acceleration is not smaller than the predetermined threshold value α, it ends the current operation.

[0089] If the HCU 10 determines that the absolute value of the motor rotation acceleration is smaller than the predetermined threshold value α, then in step S13, the HCU 10 determines whether the garage shift is a shift change from the reverse range to the forward range.

[0090] If the HCU 10 determines in step S13 that the shift has been changed from the reverse range to the forward range, the HCU 10 determines in step S14 whether the motor rotation speed is less than 0. In step S14, it is determined whether the motor rotation speed is a negative value and the vehicle 1 is moving backward.

[0091] If the HCU 10 determines that the motor rotation speed is not less than 0, it ends this operation. If the HCU 10 determines that the motor rotation speed is less than 0, the HCU 10 determines in step S15 whether the motor rotation acceleration is less than 0. In step S15, it is confirmed whether the motor rotation acceleration is a negative value and the speed of the vehicle 1 is increasing in the reverse direction.

[0092] If the HCU 10 determines that the motor rotation acceleration is not smaller than 0, it ends the current operation.

[0093] When the HCU 10 determines that the motor rotation acceleration is smaller than 0, it determines in step S16 that there is a rolling downhill of the vehicle 1. After executing step S16, the HCU 10 ends the current operation.

[0094] If it is determined in step S13 that the shift change is not from the reverse range to the forward range (if the shift change is from the forward range to the reverse range), the HCU 10 determines in step S17 whether the motor rotation speed is greater than 0. In step S17, it is confirmed whether the motor rotation speed is a positive value and the vehicle 1 is moving forward.

[0095] If the HCU 10 determines that the motor rotation speed is not greater than 0, it ends the current operation.

[0096] If the HCU 10 determines that the motor rotation speed is greater than 0, then in step S18, it determines whether the motor rotation acceleration is greater than 0. In step S18, it is confirmed whether the motor rotation acceleration is a positive value and the speed of the vehicle 1 is increasing in the forward direction.

[0097] If the HCU 10 determines that the motor rotation acceleration is not greater than 0, it ends the current operation. If the HCU 10 determines that the motor rotation acceleration is greater than 0, it determines in step S19 that the vehicle 1 is sliding downhill. After executing step S19, the HCU 10 ends the current operation.

[0098] The second skid determination process in step S3 of FIG. 3 will be described in detail with reference to FIG.

[0099] In step S21, the HCU 10 determines whether or not the range is forward.

[0100] If the HCU 10 determines in step S21 that the range is forward, then in step S22, it determines whether the motor rotation speed is less than 0. In step S22, it is determined whether the motor rotation speed is a negative value and the vehicle 1 is moving backward.

[0101] If the HCU 10 determines that the motor rotation speed is not less than 0, it ends the current operation. If the HCU 10 determines that the motor rotation speed is less than 0, it determines in step S23 that the vehicle 1 is sliding downhill. After executing step S23, the HCU 10 ends the current operation.

[0102] If the HCU 10 determines in step S21 that the range is not the forward range (if the range is the reverse range), the HCU 10 determines in step S24 whether the motor rotation speed is greater than 0. In step S24, it is confirmed whether the motor rotation speed is a positive value and the vehicle 1 is moving forward.

[0103] If the HCU 10 determines that the motor rotation speed is not greater than 0, it ends the current operation. If the HCU 10 determines that the motor rotation speed is greater than 0, it determines in step S25 that the vehicle 1 is sliding downhill. After executing step S25, the HCU 10 ends the current operation.

[0104] With reference to FIGS. 6 and 7, the flow of the first skid determination process and the second skid determination process that are performed while the vehicle is running using engine torque in the HEV running mode or while the vehicle is running in the engine running mode will be described.

[0105] The first skid determination process in step S2 of FIG. 3 will be described in detail with reference to FIG.

[0106] In step S31, the HCU 10 calculates the vehicle acceleration. Next, in step S32, the HCU 10 determines whether the garage shift is a shift change from the reverse range to the forward range.

[0107] If the HCU 10 determines in step S32 that the shift has been changed from the reverse range to the forward range, the HCU 10 determines in step S33 whether the vehicle speed is less than 0. In step S33, it is determined whether the vehicle speed is a negative value and the vehicle 1 is moving backward.

[0108] If the HCU 10 determines that the vehicle speed is not less than 0, it ends this operation. If the HCU 10 determines that the vehicle speed is less than 0, the HCU 10 determines in step S34 whether the vehicle acceleration is less than 0. In step S34, it is confirmed whether the vehicle acceleration is a negative value and the speed of the vehicle 1 is increasing in the reverse direction.

[0109] If the HCU 10 determines that the vehicle acceleration is not less than 0, it ends the current operation. If the HCU 10 determines that the vehicle acceleration is less than 0, it determines in step S35 that the vehicle 1 is sliding downhill. After executing step S35, the HCU 10 ends the current operation.

[0110] If it is determined in step S32 that the shift change is not from the reverse range to the forward range (if the shift change is from the forward range to the reverse range), the HCU 10 determines in step S36 whether the vehicle speed is greater than 0. In step S36, it is confirmed whether the vehicle speed is a positive value and the vehicle 1 is moving forward.

[0111] If the HCU 10 determines that the vehicle speed is not greater than 0, it ends the current operation.

[0112] If the HCU 10 determines that the vehicle speed is greater than 0, then in step S37, it determines whether the vehicle acceleration is greater than 0. In step S37, it is determined whether the vehicle acceleration is a positive value and the speed of the vehicle 1 is increasing in the forward direction.

[0113] If the HCU 10 determines that the vehicle acceleration is not greater than 0, it ends the current operation. If the HCU 10 determines that the vehicle acceleration is greater than 0, it determines in step S38 that the vehicle 1 is sliding downhill. After executing step S38, the HCU 10 ends the current operation.

[0114] The second skid determination process in step S3 of FIG. 3 will be described in detail with reference to FIG.

[0115] In step S41, the HCU 10 determines whether or not the range is forward.

[0116] If the HCU 10 determines in step S41 that the range is forward, it determines in step S42 whether the vehicle speed is less than 0. In step S42, it is determined whether the vehicle speed is a negative value and the vehicle 1 is moving backward.

[0117] If the HCU 10 determines that the vehicle speed is not less than 0, it ends the current operation. If the HCU 10 determines that the vehicle speed is less than 0, it determines in step S43 that the vehicle 1 is sliding downhill. After executing step S43, the HCU 10 ends the current operation.

[0118] If the HCU 10 determines in step S41 that the range is not the forward range (if the range is the reverse range), the HCU 10 determines in step S44 whether the vehicle speed is greater than 0. In step S44, it is confirmed whether the motor rotation speed is a positive value and the vehicle 1 is moving forward.

[0119] If the HCU 10 determines that the vehicle speed is not greater than 0, it ends the current operation. If the HCU 10 determines that the vehicle speed is greater than 0, it determines in step S45 that the vehicle 1 is sliding downhill. After executing step S45, the HCU 10 ends the current operation.

[0120] As described above, in this embodiment, the vehicle 1 includes at least the motor generator 4 as a driving force source that transmits power to the drive wheels 5. While the vehicle is traveling using the driving force generated by the motor generator 4, the HCU 10 determines whether or not the driver has performed a garage shift, which is an operation to change the shift position from one of the forward range or the reverse range to the other.

[0121] Next, when the HCU 10 determines that a garage shift has been performed, it performs a first skid determination process to determine whether or not the vehicle 1 has skidded. On the other hand, when the HCU 10 determines that a garage shift has not been performed, it performs a second skid determination process different from the first skid determination process to determine whether or not the vehicle 1 has skidded.

[0122] In this way, whether or not the vehicle 1 has rolled down is determined using different methods depending on whether or not a garage shift has been performed, so that even if a garage shift has been performed, it is possible to prevent an erroneous determination of whether or not the vehicle 1 has rolled down, and to accurately determine whether or not the vehicle 1 has rolled down.

[0123] Then, when it is determined by the first skid determination process or the second skid determination process that the vehicle 1 is skidding, the HCU 10 increases the driving force of the vehicle 1. This makes it possible to stop the vehicle 1 from skidding.

[0124] In this embodiment, the first skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position, the rotation speed of the motor generator 4, and the rotation acceleration of the motor generator 4.

[0125] In this way, when a garage shift is performed, whether or not the vehicle 1 is sliding down is determined based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4. This makes it possible to prevent erroneous determination of whether the vehicle 1 is sliding down, and to accurately determine whether the vehicle 1 is sliding down, even if the direction of travel before the shift change is maintained immediately after the garage shift.

[0126] More specifically, when a garage shift is performed from the reverse range to the forward range, even if the vehicle 1 is temporarily maintained in reverse immediately after the shift change, the traveling direction of the vehicle 1 will become forward after the passage of time from the shift change. In a situation in which the vehicle 1 is temporarily maintained in reverse immediately after the shift change, if a determination is made as to whether or not the vehicle 1 is rolling downhill based on the shift position and the rotation speed of the motor generator 4, as in the case where a garage shift is not performed, the shift position is in the forward range immediately after the garage shift, and the rotation speed of the motor generator 4 is a negative value (reverse direction), which temporarily does not match the shift position and the traveling direction of the vehicle 1, and therefore it will be erroneously determined that the vehicle 1 is rolling downhill.

[0127] On the other hand, in this embodiment, when a garage shift is performed, it is determined whether the vehicle 1 is sliding downhill based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4. Therefore, even if the shift position is in the forward range and the rotational speed of the motor generator 4 is a negative value (reverse direction), if the rotational acceleration of the motor generator 4 is a positive value, the reverse speed of the vehicle 1 is decelerating and the vehicle is in the process of transitioning from the reverse direction to the forward direction, so it can be accurately determined that the vehicle 1 is not sliding downhill. On the other hand, if the rotational acceleration of the motor generator 4 is a negative value, the reverse speed of the vehicle 1 is accelerating, so it can be accurately determined that the vehicle 1 is sliding downhill.

[0128] Furthermore, when a garage shift from the forward range to the reverse range is performed, even if the forward movement of the vehicle 1 is temporarily maintained immediately after the shift change, the direction of travel of the vehicle 1 will become reverse after the passage of time from the shift change. In a situation in which the forward movement of the vehicle 1 is temporarily maintained immediately after the shift change, if a determination is made as to whether or not the vehicle 1 is rolling down based on the shift position and the rotation speed of the motor generator 4, as in the case where a garage shift is not performed, the shift position is in the reverse range immediately after the garage shift, and the rotation speed of the motor generator 4 is a positive value (forward direction), which temporarily does not match the shift position and the direction of travel of the vehicle 1, and therefore it will be erroneously determined that the vehicle 1 is rolling down.

[0129] On the other hand, in this embodiment, when a garage shift is performed, it is determined whether the vehicle 1 is sliding downhill based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4. Therefore, even if the shift position is in the reverse range and the rotational speed of the motor generator 4 is a positive value (forward direction), if the rotational acceleration of the motor generator 4 is a negative value, the forward speed of the vehicle 1 is decelerating and the vehicle is in the process of transitioning from the forward direction to the reverse direction, so it can be accurately determined that the vehicle 1 is not sliding downhill. On the other hand, if the rotational acceleration of the motor generator 4 is a positive value, the forward speed of the vehicle 1 is accelerating, so it can be accurately determined that the vehicle 1 is sliding downhill.

[0130] Therefore, it is possible to prevent an erroneous determination that the vehicle 1 is sliding down when it is not, and to prevent an unnecessary increase in driving force.

[0131] In this embodiment, the second skid determination process is a process for determining whether or not the vehicle 1 is skidding based on the shift position and the rotation speed of the motor generator 4.

[0132] As a result, when a garage shift is not being performed, whether or not the vehicle 1 is rolling down is determined based on the shift position and the rotational speed of the motor generator 4, thereby shortening the time required to determine whether or not the vehicle 1 is rolling down compared to when a garage shift is being performed and whether or not the vehicle 1 is rolling down is determined based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4.

[0133] Here, the rotational acceleration of the motor generator 4 is a differential value of the rotational speed of the motor generator 4. Because the driving force generated by the motor generator 4 is transmitted to the drive wheels 5 via gears of the power transmission mechanism, the rotational acceleration of the motor generator 4 may suddenly change due to rotation changes caused by gear backlash or vehicle body vibration. For this reason, if the presence or absence of the vehicle 1 is determined based on the shift position, the rotational speed, and the rotational acceleration of the motor generator 4, as in the first rollover determination, it would be necessary to monitor the rotational acceleration of the motor generator 4 for a certain period of time to eliminate the effects of gear backlash, etc., which could lengthen the time required to determine whether the vehicle 1 is rolling over. On the other hand, in this embodiment, when a garage shift is not being performed, the presence or absence of the vehicle 1 is determined based on the shift position and the rotational speed of the motor generator 4, thereby shortening the time required to determine whether the vehicle 1 is rolling over.

[0134] In this embodiment, the first skid determination process is a process that determines whether the vehicle 1 is skidding based on whether the absolute value of the rotational acceleration of the motor generator 4 is smaller than a predetermined threshold value, and based on the shift position, the rotational speed of the motor generator 4, and the rotational acceleration of the motor generator 4.

[0135] This makes it possible to prevent an erroneous determination that the vehicle 1 is sliding down when it is not. More specifically, in this embodiment, the rotation speed of the motor-generator 4 is calculated based on the detection results of the resolver, and is therefore highly accurate, but because of this high accuracy, the detected value of the rotation speed may suddenly change due to gear backlash. A sudden change in rotation speed due to gear backlash is unrelated to whether the vehicle 1 is sliding down. Therefore, if the absolute value of the rotational acceleration of the motor-generator 4 is greater than a predetermined threshold value, that value is excluded from the determination of whether the vehicle 1 is sliding down, thereby preventing erroneous determination of whether the vehicle 1 is sliding down.

[0136] In this embodiment, the first skid determination process may be a process for determining whether or not the vehicle 1 is skidding based on the shift position, the speed of the vehicle 1, and the acceleration of the vehicle 1.

[0137] In this way, by determining whether or not vehicle 1 is rolling downhill based on the shift position, the speed of vehicle 1, and the acceleration of vehicle 1, it is possible to accurately determine whether vehicle 1 is rolling downhill even when a garage shift is performed.

[0138] In this embodiment, the second skid determination process may be a process for determining whether or not the vehicle 1 is skidding based on the shift position and the speed of the vehicle 1.

[0139] In this way, when a garage shift is not being performed, by determining whether or not vehicle 1 is rolling down based on the shift position and the speed of vehicle 1, the time required to determine whether or not vehicle 1 is rolling down can be shortened compared to when a garage shift is being performed and the determination is made based on the shift position, the speed of vehicle 1, and the acceleration of vehicle 1.

[0140] In this embodiment, the vehicle 1 is equipped with a motor generator 4 and an engine 2 as driving force sources, and when the first or second rolling-down judgment process determines that the vehicle 1 is rolling down, the HCU 10 starts the engine 2 to increase the driving force of the vehicle 1.

[0141] As a result, even when the driving force generated by the motor generator 4 cannot be increased, the driving force of the vehicle 1 can be increased by the engine torque.

[0142] Note that the motor generator 4 generates a large amount of heat when the motor rotation speed is near 0 rpm, and therefore the driving force generated by the motor generator 4 may not be increased due to the high temperature of the motor generator 4. Also, the driving force generated by the motor generator 4 may not be increased due to a decrease in the SOC of the battery (second power storage device 33) that supplies power to the motor generator 4. Even when the driving force generated by the motor generator 4 cannot be increased, the driving force of the vehicle 1 can be increased by starting the engine 2 using engine torque.

[0143] In this embodiment, the vehicle 1 includes at least an engine 2 as a driving force source that transmits power to the drive wheels 5. The HCU 10 determines whether or not a garage shift, which changes the shift position from one of the forward range or the reverse range to the other, has been performed by the driver while the vehicle is traveling using the driving force generated by the engine 2. If it is determined that a garage shift has been performed, the HCU 10 performs a first skid determination process to determine whether or not the vehicle 1 is skidding. If it is determined that a garage shift has not been performed, the HCU 10 performs a second skid determination process different from the first skid determination process to determine whether or not the vehicle 1 is skidding. If it is determined that the vehicle 1 is skidding by the first skid determination process or the second skid determination process, the HCU 10 increases the driving force of the vehicle 1.

[0144] In this way, whether or not the vehicle 1 has rolled down is determined using different methods depending on whether or not a garage shift has been performed, so that even if a garage shift has been performed, it is possible to prevent an erroneous determination of whether or not the vehicle 1 has rolled down, and to accurately determine whether or not the vehicle 1 has rolled down.

[0145] In addition, if the first or second skid determination process determines that the vehicle 1 is skidding, the driving force of the vehicle 1 is increased, thereby preventing the vehicle 1 from skidding.

[0146] In this embodiment, the first skid determination process while the vehicle is traveling using the driving force generated by the engine 2 is a process that determines whether or not the vehicle 1 is skidding based on the shift position, the speed of the vehicle 1, and the acceleration of the vehicle 1.

[0147] In this way, by determining whether or not vehicle 1 is rolling downhill based on the shift position, the speed of vehicle 1, and the acceleration of vehicle 1, it is possible to accurately determine whether vehicle 1 is rolling downhill even when a garage shift is performed.

[0148] In this embodiment, the second skid determination process while the vehicle is traveling by the driving force generated by the engine 2 is a process for determining whether or not the vehicle 1 is skidding based on the shift position and the speed of the vehicle 1.

[0149] In this way, when a garage shift is not being performed, by determining whether or not vehicle 1 is rolling down based on the shift position and the speed of vehicle 1, the time required to determine whether or not vehicle 1 is rolling down can be shortened compared to when a garage shift is being performed and the determination is made based on the shift position, the speed of vehicle 1, and the acceleration of vehicle 1.

[0150] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0151] 1 vehicle 2. Engine (internal combustion engine) 4 Motor generator (motor) 5 drive wheels 10 HCU (garage shift determination unit, first slide-down determination unit, second slide-down determination unit, control unit)

Claims

1. A control device for a vehicle having at least a motor as a driving force source that transmits power to driving wheels, a garage shift determination unit that determines whether a garage shift, which is an operation of changing the shift position from one of a forward range or a reverse range to the other, has been performed by the driver while the vehicle is traveling using the driving force generated by the motor; a first skid-down determination unit that, when it is determined by the garage shift determination unit that the garage shift has been performed, performs a first skid-down determination process to determine whether or not the vehicle has skidded; a second skid-down determination unit that, when it is determined by the garage shift determination unit that the garage shift is not being performed, performs a second skid-down determination process different from the first skid-down determination process to determine whether or not the vehicle is skidding; A control device for a vehicle, comprising: a control unit that increases the driving force of the vehicle when it is determined that the vehicle is skidding by the first skidding determination process or the second skidding determination process.

2. 2. The vehicle control device according to claim 1, wherein the first skid determination process is a process for determining whether the vehicle is skidding or not based on the shift position, the rotation speed of the motor, and the rotation acceleration of the motor.

3. 3. The vehicle control device according to claim 2, wherein the second rolling-down determination process is a process for determining whether or not the vehicle is rolling down based on the shift position and the rotation speed of the motor.

4. The vehicle control device according to claim 2, characterized in that the first skid determination process is a process for determining whether the vehicle is skidding or not based on whether the absolute value of the rotational acceleration of the motor is smaller than a predetermined threshold value, and based on the shift position, the rotational speed of the motor, and the rotational acceleration of the motor.

5. 2. The vehicle control device according to claim 1, wherein the first rolling-down determination process is a process for determining whether or not the vehicle is rolling down a slope based on the shift position, the speed of the vehicle, and the acceleration of the vehicle.

6. 6. The vehicle control device according to claim 5, wherein the second rolling-down determination process is a process for determining whether or not the vehicle is rolling down based on the shift position and the speed of the vehicle.

7. the vehicle includes the motor and an internal combustion engine as the driving power source, A vehicle control device as described in any one of claims 1 to 6, characterized in that the control unit starts the internal combustion engine to increase the driving force of the vehicle when it is determined that the vehicle is skidding by the first skidding determination process or the second skidding determination process.

8. A control device for a vehicle having at least an internal combustion engine as a driving force source that transmits power to driving wheels, a garage shift determination unit that determines whether a garage shift, which changes the shift position from one of a forward range or a reverse range to the other, has been performed by the driver while the vehicle is traveling using the driving force generated by the internal combustion engine; a first skid-down determination unit that, when it is determined by the garage shift determination unit that the garage shift has been performed, performs a first skid-down determination process to determine whether or not the vehicle has skidded; a second skid-down determination unit that, when it is determined by the garage shift determination unit that the garage shift is not being performed, performs a second skid-down determination process different from the first skid-down determination process to determine whether or not the vehicle is skidding; A control device for a vehicle, comprising: a control unit that increases the driving force of the vehicle when it is determined that the vehicle is skidding by the first skidding determination process or the second skidding determination process.

9. 9. The vehicle control device according to claim 8, wherein the first rolling-down determination process is a process for determining whether or not the vehicle is rolling down a slope based on the shift position, the speed of the vehicle, and the acceleration of the vehicle.

10. 10. The vehicle control device according to claim 9, wherein the second rolling-down determination process is a process for determining whether or not the vehicle is rolling down based on the shift position and the speed of the vehicle.

Images