Vehicular driving device

Abstract

To make heating values during warming-up in a first rotary electric machine and a second rotary electric machine larger.SOLUTION: A vehicular driving device (1) is provide with: a first rotary electric machine (2) that is driving-connected to either of front wheels (7FL and 7FR) and rear wheels (7RL and 7RR) of a vehicle (100); a second rotary electric machine (3) which is driven independently from the first rotary electric machine (2) and which is driving-connected to the other of the front wheels (7FL and 7FR) and the rear wheels (7RL and 7RR); and a control part (10) that controls the first rotary electric machine (2) and the second rotary electric machine (3), in accordance with required driving force. When executing heat-generation control of warming-up the vehicle (100), the control part (10) controls the first rotary electric machine (2) so that the machine generates first cancelling / driving force (Tcan1) and controls the second rotary electric machine (3) so that the machine generates second cancelling / driving force (Tcan2) that acts on the opposite side in a running direction of the vehicle (100) with respect to the first cancelling / driving force (Tcan1).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle drive device including a first rotating electric machine drivingly connected to one of front wheels and rear wheels, and a second rotating electric machine drivingly connected to the other of the wheels. [Background technology]

[0002] For example, in a vehicle drive device mounted on an electric vehicle, when the temperature of the battery is low, the efficiency of charging and discharging decreases. In particular, when the battery is extremely cold (for example, below 0 degrees), it becomes difficult to charge the battery, and even when the vehicle decelerates while traveling, regeneration cannot be performed, resulting in a problem of reduced power consumption. For this reason, when traveling a vehicle that has been left in a low-temperature environment for a long time, for example, it is required to warm up the vehicle quickly, but it is more difficult to warm up an electric vehicle than a hybrid vehicle that is equipped with an internal combustion engine as a heat source. Therefore, a device has been proposed that, while the vehicle is stopped or traveling, a d-axis current is passed through the traveling motor in addition to the q-axis current that provides driving force, thereby warming up the traveling motor extra, thereby accelerating the warming up of the battery (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-165526 ​​A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the above-mentioned Patent Document 1, where the d-axis current is passed to warm up the driving motor, the increase in the amount of heat generated by the driving motor is limited, and the warm-up time is long, particularly in an extremely low temperature environment, making it insufficient for practical use. For this reason, it is possible to warm up the battery by installing a high-voltage heater, for example, but high-voltage heaters are expensive and hinder the cost reduction of the vehicle.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a vehicle drive device capable of increasing the amount of heat generated during warm-up in the first rotating electric machine and the second rotating electric machine. [Means for solving the problem]

[0006] One aspect of the present invention is a vehicle drive device comprising a first rotating electric machine drivingly connected to one of the front wheels and rear wheels of a vehicle, a second rotating electric machine driven independently of the first rotating electric machine and drivingly connected to the other of the front wheels and the rear wheels, and a control unit that controls the first rotating electric machine and the second rotating electric machine, wherein when performing heat generation control to warm up the vehicle, the control unit controls the first rotating electric machine to generate a first counteracting driving force, and controls the second rotating electric machine to generate a second counteracting driving force acting on the opposite side of the vehicle's direction of travel with respect to the first counteracting driving force. Effect of the Invention

[0007] According to the present invention, the amount of heat generated during warm-up in the first rotating electric machine and the second rotating electric machine can be increased, and the warm-up time can be shortened. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing the configuration of a vehicle and a vehicle drive device according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which the vehicle according to the first embodiment is stopped. [Diagram 3] 2A to 2C are schematic diagrams showing states during acceleration and steady running while the vehicle according to the first embodiment is running forward. [Figure 4] FIG. 2 is a schematic diagram showing a state in which the vehicle according to the first embodiment is decelerating while traveling forward. [Diagram 5] FIG. 2 is a schematic diagram showing a state in which the vehicle according to the first embodiment is being charged while stopped. [Figure 6] FIG. 2 is a schematic diagram showing a state during acceleration while the vehicle according to the first embodiment is traveling backward. [Figure 7]4 is a flowchart showing ON / OFF control of heat creation control according to the first embodiment. [Figure 8] 4 is a flowchart showing vehicle state control according to the first embodiment. [Figure 9] 10 is a time chart showing an example of driving when heat generation control according to the second embodiment is executed. [Figure 10] 5 is a time chart showing an example of driving when heat generation control according to a comparative example is executed; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment A vehicle drive device 1 according to a first embodiment will be described below with reference to FIGS. 1 to 8. FIG.

[0010] [Vehicle configuration] First, the configuration of a vehicle 100 on which the vehicle drive device 1 is mounted will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing the configuration of a vehicle according to the first embodiment and the vehicle drive device. As shown in FIG. 1, the vehicle 100, which is a four-wheel drive electric vehicle on which the vehicle drive device 1 is mounted, travels forward in the upward direction in the figure, and includes left and right front wheels 7FL, 7FR, left and right rear wheels 7RL, 7RR, a battery unit 20, the vehicle drive device 1 that drives the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR using the power of the battery unit 20, a compressor 30 for air conditioning the interior of the vehicle, and the like. In addition, brakes 9, such as disc brakes, are provided on the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR, respectively, as an example of a brake device.

[0011] The vehicle 100 is also provided with a driver's seat 50, which is shown in a simplified manner, and the driver's seat 50 is provided with a shift lever 51, an accelerator pedal 52, a brake pedal 53, a mode select switch 54, a car navigation system 55, a steering sensor 56, etc. The vehicle 100 is also provided with a camera 61, a corner sensor 62, etc.

[0012] The shift lever 51 is configured to allow the driver to select a shift range, such as a parking range, neutral range, drive range, or reverse range, and transmits a signal of the selected shift range to the ECU 10, which will be described in detail later. The accelerator pedal 52 is configured to be capable of detecting the accelerator opening, and transmits a signal of the accelerator opening to the ECU 10, which receives the signal and detects the driver's required driving force Trq based on the accelerator opening. The brake pedal 53 is configured to be capable of detecting the brake pedal pressure, and transmits a signal of the brake pedal pressure to the ECU 10, which receives the signal and detects the driver's required deceleration force Tdec based on the brake pedal pressure (amount of pressure applied).

[0013] The mode select switch 54 is configured to be able to selectively switch between, for example, a normal mode in which the vehicle characteristics, particularly the acceleration characteristics, are set to a normal first acceleration characteristic, and a sport mode in which the acceleration characteristics are set to a second acceleration characteristic that realizes driving that is more dynamic than the first acceleration characteristic, by the driver. That is, when the driver wants to drive in a sporty manner, the mode select switch 54 is configured to be able to select the sport mode in which the response of acceleration and deceleration is made faster than in the normal mode and the output characteristics of the driving force relative to the accelerator opening are increased. That is, a signal indicating that one of these modes has been selected is sent to the ECU 10, and the ECU 10 changes the characteristics of the vehicle 100 by controlling the front motor 2 and the rear motor 3, which will be described later. In addition to the normal mode and the sport mode, the mode select switch 54 may be configured to be able to select an eco mode in which the output characteristics of the driving force are lowered to a level lower than in the normal mode to reduce fuel consumption (electricity consumption).

[0014] The car navigation system 55 is configured to display the current position, a map, etc. to the driver, and to guide the driver along the route to the destination when the destination is set. In addition, when the destination is set, the car navigation system 55 is configured to calculate the distance of the route from the current position of the vehicle 100 to the destination and the time required to arrive at the destination (estimated arrival time). The car navigation system 55 is equipped with a calculation unit such as a CPU (not shown), and various pieces of information calculated therein are configured to be transmittable to the ECU 10.

[0015] The steering sensor 56 is configured to detect a steering angle when the driver turns a steering wheel (not shown) in the driver's seat 50. A signal of the steering angle detected by the steering sensor 56 is transmitted to the ECU 10.

[0016] On the other hand, the camera 61 is disposed so as to be able to capture an image ahead of the vehicle 100. The ECU 10, which will be described later, is configured to analyze the image captured by the camera 61, identify vehicles, bicycles, people, traffic lights, and the like ahead, and enable driving assistance and automatic driving while the vehicle 100 is traveling based on the analysis results.

[0017] A plurality of corner sensors 62 are arranged on the sides of the vehicle 100, and radiate, for example, ultrasonic waves or millimeter waves toward the periphery (front, rear, left and right sides) of the vehicle 100 and detect the reflection of the waves. The ECU 100, which will be described later, is configured to be able to determine the distance to an obstacle or the like using the detection results of the corner sensors 62 and to determine, for example, that a person, a vehicle, or the like is approaching.

[0018] In addition, the parking range and neutral range are non-driving ranges that prevent the vehicle 100 from driving, the drive range is a forward range (driving range) that causes the vehicle 100 to drive forward, and the reverse range is a reverse range (driving range) that causes the vehicle 100 to drive backward.

[0019] In addition, in this embodiment, the required driving force Trq is described as being detected based on the accelerator opening, which is the amount of operation of the accelerator pedal 52 by the driver. However, this is not limited to this, and the required driving force Trq may be determined by the control unit, for example, by automatic driving, cruise control, etc.

[0020] Similarly, in this embodiment, the required deceleration force Tdec is described as being detected based on the brake pedal pressure, which is the amount of operation of the brake pedal 53 by the driver, but this is not limited to the above, and the required deceleration force Tdec may be determined by the control unit, for example, by automatic driving, cruise control, etc.

[0021] The vehicle drive device 1 includes a front motor 2, which is a three-phase brushless DC motor as a first rotating electric machine (motor generator) drivingly connected to the front wheels 7FL, 7FR, a rear motor 3, which is a three-phase brushless DC motor as a second rotating electric machine (motor generator) that is driven independently of the front motor 2 and is drivingly connected to the left and right rear wheels 7RL, 7RR, a drive circuit 5 that can freely control the drive force (regenerative force) by supplying a drive current (electric power) to the front motor 2 and the rear motor 3, and a control unit (ECU) 10 that can control the drive circuit 5. That is, the front motor 2 is configured to be able to rotate and drive the front wheels 7FL, 7FR or to generate regenerative power, and the rear motor 3 is configured to be able to rotate and drive the left and right rear wheels 7RL, 7RR or to generate regenerative power. The drive circuit 5 is also configured to be able to directly supply a drive current (electric power) to a compressor 30 without passing through a battery unit 20.

[0022] 1, the front motor 2 and the rear motor 3 are simply shown as motors, but are generally configured as drive units equipped with a reduction gear mechanism, a differential device, etc., which are not shown. In addition, the control unit 10 that performs various controls in this embodiment is described as being provided in the vehicle drive device 1, but may be another control unit provided in the vehicle 100.

[0023] [Vehicle state control] Next, in the first embodiment, state control for transitioning between modes according to the state of the vehicle 100, which is controlled by the control unit 10 of the vehicle drive device 1, will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the vehicle state control according to the first embodiment. Note that the vehicle state control shown in Fig. 8 is repeatedly executed at predetermined time intervals according to the processing speed of the control unit 10, for example, and the state set in each mode transitions as the judgment changes.

[0024] In detail, as shown in Fig. 8, when the start switch of the vehicle 100 is turned on, the control unit 10 starts this state control, and first, based on a signal from a position detection sensor (not shown), determines whether the position of the shift lever 51 is in a non-driving range such as a parking range or a neutral range (S11). Next, when the control unit 10 determines that the shift lever 51 is in a non-driving range (YES in S11), it determines whether the vehicle is being charged (S12). When the control unit 10 determines that the vehicle 100 is connected to an external charger 200 (Fig. 5), that is, when the vehicle is being charged (YES in S12), it sets the state of the vehicle 100 to a charging mode (S14). When the control unit 10 determines that the vehicle is not being charged (NO in S12), it sets the state of the vehicle 100 to a stop mode (S15).

[0025] On the other hand, when the control unit 10 determines that the vehicle is not in the non-driving range based on the position of the shift lever 51 (NO in S11), it determines whether the vehicle is in the drive range (forward range) based on the position of the shift lever 51 (S13). When the control unit 10 determines that the vehicle is in the drive range (YES in S13), it sets the state of the vehicle 100 to the forward mode (S16), and when the control unit 10 determines that the vehicle is not in the drive range (NO in S13), that is, the vehicle is in the reverse range (reverse range), it sets the state of the vehicle 100 to the reverse mode (S17). When the vehicle 100 is in the forward mode or reverse mode, it can distinguish between a state in which the vehicle 100 is accelerating or steadily running based on the required driving force Trq and a state in which the vehicle 100 is decelerating based on the required deceleration force Tdec.

[0026] [Heat generation control ON / OFF control] Next, the ON / OFF control of the heat creation control for warming up the vehicle 100, which is controlled by the control unit 10 of the vehicle drive device 1 in the first embodiment, will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the ON / OFF control of the heat creation control according to the first embodiment. Note that the ON / OFF control of the heat creation control shown in Fig. 7 is also repeatedly executed at predetermined time intervals according to the processing speed of the control unit 10, for example, and the ON / OFF of the heat creation control is switched as the judgment changes.

[0027] 7, for example, when the start switch of the vehicle 100 is turned on, the control unit 10 starts ON / OFF control of the heat creation control, and first determines whether the air conditioning in the vehicle 100 is ON (S1). If the air conditioning is ON (YES in S1), the control unit 10 determines whether the temperature of the coolant circulating through the front motor 2, rear motor 3, battery unit 20, drive circuit 5, compressor 30, etc. is less than 40 degrees (S2). If the air conditioning is ON (YES in S1) and the coolant temperature is less than 40 degrees (YES in S2), the control unit 10 determines that the heat creation control is ON because the heat used for heating by the air conditioning cannot be obtained from the coolant, that is, executes the heat creation control (S4).

[0028] Furthermore, when the air conditioning is not ON (NO in S1), or when the air conditioning is ON but the water temperature is 40 degrees or higher (YES in S1 and NO in S2), the control unit 10 determines whether the temperature of the battery unit 20 (i.e., the battery) is below 0 degrees (S3). Even in this case, if the temperature of the battery unit 20 is below 0 degrees (YES in S3), the control unit 10 determines to turn on the heat creation control, that is, executes the heat creation control (S4). Then, when the temperature of the battery unit 20 is 0 degrees or higher (NO in S3), the control unit 10 determines to turn off the heat creation control, that is, does not execute the heat creation control (S5), and sets the vehicle in a normal driving state.

[0029] [Problems with general motor heat control] Here, problems with general motor heat generation control will be described. The front motor 2 and rear motor 3 according to the first embodiment are configured as three-phase brushless DC motors. In general, when a three-phase brushless DC motor is used to generate heat without outputting torque, a current larger than normal is passed only to a single-phase coil while the vehicle is stopped to generate heat. However, when a large current is passed through a single-phase coil while the vehicle is stopped, for example, when the vehicle moves slightly due to some external cause, causing a change in rotation of the motor, a large driving force is output from the motor, which may cause a shock or the like. In addition, when the vehicle is started, a local driving force is generated by the single-phase coil, and even if a command is issued to control the rotation smoothly, it is difficult to make the current control follow the local driving force. Furthermore, since the control is performed by passing a current only through a single-phase coil, there is also a problem that it takes a long time to warm up the motor when the amount of heat generated is small and the motor, battery unit, coolant, etc. are at extremely low temperatures. Therefore, when it is determined that the heat creation control is ON as described above and it is decided to execute the heat creation control, in the first embodiment, the following heat creation control is executed in each mode.

[0030] [When heat generation control is executed] Next, detailed operations during execution of heat generation control in the first embodiment will be described with reference to Figs. 2 to 6. In the following description, heat generation is basically performed by reversing the output direction of the driving force of the front motor 2 and the rear motor 3 relative to the vehicle travel direction to cancel each other out, but since the detailed operations differ in each driving state (each mode), each driving state (each mode) will be described separately. Generally, the battery unit 20 has a property that, although it is difficult to charge when it is in a low temperature state below 0 degrees, it can output electricity if there is a remaining charge. For this reason, in the heat generation control described below, the control unit 10 controls the battery unit 20 to output electric power but not to charge the battery unit 20.

[0031] (Heat generation control when stationary) First, the operation of the heat generation control in a state where the vehicle 100 is stopped without charging (stop mode) will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing a state when the vehicle according to the first embodiment is stopped. In the stop mode shown in Fig. 2, the brake pedal 53 is depressed and the brake 9 is ON (operated and locked) (BRK ON), or the brake 9 of the vehicle 100 is ON (locked) by brake hold or the like even if the brake pedal 53 is not depressed, or other brakes (so-called parking brakes or side brakes) (not shown) are ON (locked), and the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR of the vehicle 100 are forcibly fixed.

[0032] When the control unit 10 determines the stop mode through the vehicle state control and determines that the heat generation control is ON through the ON / OFF control of the heat generation control, as shown in Figure 2, it powers the front motor 2 using the power of the battery unit 20 so that the front motor 2 generates a backward driving force TF1 as a first counteracting driving force Tcan1 at the left and right front wheels 7FL, 7FR, and powers the rear motor 3 using the power of the battery unit 20 so that, while synchronized with the front motor 2, the rear motor 3 generates a forward driving force TR1 as a second counteracting driving force Tcan2 acting on the opposite side of the traveling direction of the vehicle 100 and having the same magnitude as the driving force TF1 at the front wheels 7FL, 7FR.

[0033] In this case, it is safer if the driving force TF1 of the front wheels 7FL, 7FR output by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR output by the rear motor 3 are smaller than the braking force that stops the rotation of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR by turning on the brake 9, for example, but since these driving forces TF1 and TR1 are in a direction that cancels each other out, they may be larger than the braking force of the brake 9. In addition, it is preferable that the rotation speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR are detected by an ABS sensor (not shown) or the like, and when it is determined that the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR are not rotating, the driving of the front motor 2 and the rear motor 3 by this heat generation control is permitted, and when the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR rotate due to slippage, for example, the driving of the front motor 2 and the rear motor 3 is stopped.

[0034] In addition, in this stop mode, the front motor 2 and the rear motor 3 are powered and no power is generated by regeneration from the front motor 2 as in the drive mode described in detail below, and therefore the compressor 30 is not driven. However, it is possible to drive the compressor 30 using power from the battery unit 20 to heat the interior of the vehicle.

[0035] As described above, in heat generation control in the stop mode, the driving force TF1 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR by the rear motor 3 are output so as to cancel each other out in the direction of travel of the vehicle 100. This makes it possible to pass a larger current through the front motor 2 and the rear motor 3 than when current is passed through, for example, a single-phase coil. This allows the amount of heat generated during warm-up to be increased, and the warm-up time to be shortened.

[0036] (Heat generation control during acceleration and steady driving while driving forward) Next, the operation of the heat generation control in a state (forward mode) in which the vehicle 100 is accelerating or running steadily while traveling forward will be described with reference to FIG. 3. FIG. 3 is a schematic diagram showing a state during acceleration and steady running of the vehicle according to the first embodiment during forward running. In the forward mode shown in FIG. 3, the brake pedal 53 is not depressed and the brake 9 is OFF (released) (BRK OFF), and other brakes (so-called parking brakes and side brakes) not shown in particular are also OFF (released), and the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR of the vehicle 100 are rotatable. In addition, steady running is a state in which the running resistance of the vehicle 100 and the driving force in the accelerating direction (required driving force Trq) are in balance, and in a broad sense, the operation of the vehicle 100 is the same as that during acceleration. Furthermore, if the running resistance of the vehicle 100 is greater than the driving force in the accelerating direction (required driving force Trq), the speed of the vehicle 100 will decrease, but in a broad sense, the operation of the vehicle 100 can be said to be in the same state as when accelerating.

[0037] When the control unit 10 determines the forward mode by the vehicle state control and determines the ON of the heat generation control by the ON / OFF control of the heat generation control, and determines that there is a required driving force Trq based on the accelerator opening degree of the accelerator pedal 52, as shown in Fig. 3, the control unit 10 controls the rear motor 3 using the power of the battery unit 20 so that a forward driving force TR2, which is the sum of the second counteracting driving force Tcan2 and the required driving force Trq, is generated by the rear motor 3 at the left and right rear wheels 7RL, 7RR, as shown in Fig. 3, and controls the front motor 2 to regenerate so that a backward driving force TF2 as the first counteracting driving force Tcan1 is generated by the front motor 2 at the left and right front wheels 7FL, 7FR while synchronizing with the powering control of the rear motor 3. In other words, the control unit 10 sets the magnitude of the powering of the rear motor 3 and the regeneration of the front motor 2 so that the difference between the driving force TR2 of the rear wheels 7RL, 7RR by the rear motor 3 and the driving force TF2 of the front wheels 7FL, 7FR by the front motor 2 becomes the required driving force Trq. That is, while generating a driving force TF2 for the front wheels 7FL, 7FR from the front motor 2, a driving force TR2 for the rear wheels 7RL, 7RR is generated from the rear motor 3 so as to be larger than the driving force TF2 for the front wheels 7FL, 7FR. Note that, although it depends on the output performance of the front motor 2 and the rear motor 3, it is preferable to set so that the required driving force Trq is generated as the driving force for the vehicle 100 according to the limit value of either one of them.

[0038] During acceleration or steady driving during forward driving, the rear motor 3 is supplied with power from the battery unit 20, but the power regenerated by the front motor 2 is also supplied to the rear motor 3 via the drive circuit 5. Therefore, the amount of power consumed by the battery unit 20 can be significantly reduced compared to, for example, when both the front motor 2 and the rear motor 3 are powered. In addition, by supplying a portion of the power regenerated by the front motor 2 to the compressor 30, the vehicle interior can be air-conditioned (heated) without using the power of the battery unit 20. In particular, for example, when the vehicle 100 is accelerating while traveling downhill, the front motor 2 can perform regeneration, so that even if the battery unit 20, which is in a low temperature state, cannot be charged, power can be supplied to the compressor 30, and the vehicle interior can be air-conditioned (heated) without increasing the power consumption of the battery unit 20. Therefore, by controlling the front motor 2 to regenerate in this manner, the electric power consumption of the vehicle can be improved.

[0039] Furthermore, even during acceleration during forward travel and steady travel, it is preferable to detect the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR using an ABS sensor (not shown) or the like, and if it is determined that the deviation in the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR is small, to permit regeneration of the front motor 2 and driving (powering) of the rear motor 3 through this heat generation control, and to stop regeneration of the front motor 2 and driving of the rear motor 3 if the deviation in the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR becomes large due to, for example, slippage, etc.

[0040] In the first embodiment, the front motor 2 performs regeneration while the rear motor 3 performs powering, but the front motor 2 may perform powering while the rear motor 3 performs regeneration. However, although it depends on the weight distribution between the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR of the vehicle 100, regeneration by the front motor 2 generally has higher regeneration efficiency and can improve electricity consumption. In addition, the control unit 10 may control the front motor 2 and the rear motor 3 to switch between powering and regeneration during travel depending on the travel situation, such as cornering, travelling uphill, travelling downhill, etc., including deceleration during forward travel, which will be described later.

[0041] As described above, in heat generation control during acceleration and steady driving during forward driving (driving mode), the driving force TF2 for the front wheels 7FL, 7FR by the front motor 2 and the driving force TR2 for the rear wheels 7RL, 7RR by the rear motor 3 are output so as to cancel each other out in the traveling direction of the vehicle 100, which makes it possible to pass a larger current through the front motor 2 and the rear motor 3 than when a current is passed through, for example, a single-phase coil, so that the amount of heat generated during warm-up can be increased and the warm-up time can be shortened. Also, in this heat generation control during acceleration and steady driving during forward driving (driving mode), regeneration is performed by the front motor 2, thereby improving the electric power consumption of the vehicle.

[0042] (Heat generation control during deceleration while driving forward) Next, the operation of the heat generation control in a state where the vehicle 100 is decelerating while traveling forward (forward mode) will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing a state when the vehicle according to the first embodiment is decelerating while traveling forward. In the forward mode shown in Fig. 4, the brake pedal 53 is depressed and the brake 9 is ON (activated and slipping) (BRK ON), and other brakes (not shown, in particular so-called parking brakes and side brakes) are OFF (released), and the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR of the vehicle 100 are rotating.

[0043] When the control unit 10 determines the forward mode by the vehicle state control and determines the ON of the heat generation control by the ON / OFF control of the heat generation control, and determines that there is a required deceleration force Tdec based on the amount of depression of the brake pedal 53, etc., it controls the rear motor 3 using the power of the battery unit 20 so that the rear motor 3 generates a forward driving force TR3 as a second counteracting driving force Tcan2 on the left and right rear wheels 7RL, 7RR, as shown in Fig. 4, and regeneratively controls the front motor 2 so that the front motor 2 generates a backward driving force TF3 as a first counteracting driving force Tcan1 on the left and right front wheels 7FL, 7FR while synchronizing with the power running control of the rear motor 3. That is, the control unit 10 controls so that the driving force TR3 of the rear wheels 7RL, 7RR by the rear motor 3 and the driving force TF3 of the front wheels 7FL, 7FR by the front motor 2 are the same in magnitude, thereby controlling so that the required deceleration force Tdec is generated by the braking force of the brake 9. Also, although it depends on the output performance of the front motor 2 and the rear motor 3, it is preferable to set the magnitude of regeneration of the front motor 2 and power running of the rear motor 3 according to the limit value of one of them.

[0044] During this deceleration while traveling forward, a small amount of power is supplied from the battery unit 20 to the rear motor 3, but essentially, power regenerated by the front motor 2 is supplied to the rear motor 3 via the drive circuit 5. For this reason, the amount of power consumed by the battery unit 20 is small, and can be significantly reduced compared to, for example, when both the front motor 2 and the rear motor 3 are powered. Also, as during acceleration while traveling forward, by supplying a portion of the power regenerated by the front motor 2 to the compressor 30, it is possible to perform air conditioning (heating) inside the vehicle without using power from the battery unit 20. Therefore, by controlling the front motor 2 to regenerate in this manner, it is possible to improve the electric power consumption of the vehicle.

[0045] Even when decelerating during forward travel, it is preferable to detect the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR using an ABS sensor (not shown), and if it is determined that the deviation in the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR is small, to permit regeneration of the front motor 2 through this heat generation control and driving (powering) of the rear motor 3, and to stop regeneration of the front motor 2 and driving of the rear motor 3 if the deviation in the rotational speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR becomes large due to, for example, slippage, etc.

[0046] Similarly, in the first embodiment, regeneration is performed by the front motor 2 while powering is performed by the rear motor 3, but the reverse may be true: regeneration is performed by the rear motor 3 while powering is performed by the front motor 2. However, although it depends on the weight distribution between the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR of the vehicle 100, regeneration by the front motor 2 generally has higher regeneration efficiency and can improve electricity consumption. Furthermore, the control unit 10 may control the powering and regeneration of the front motor 2 and the rear motor 3 to be switched during traveling depending on the traveling conditions, such as cornering, traveling uphill, traveling downhill, etc., including during acceleration during forward traveling and during steady traveling as described above.

[0047] As described above, in heat generation control during deceleration during forward travel (travel mode), the driving force TF3 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR3 of the rear wheels 7RL, 7RR by the rear motor 3 are output so as to cancel each other out in the traveling direction of the vehicle 100, which makes it possible to pass a larger current through the front motor 2 and the rear motor 3 than when a current is passed through, for example, a single-phase coil, so that the amount of heat generated during warm-up can be increased and the warm-up time can be shortened. Also, in this heat generation control during deceleration during forward travel (travel mode), regeneration is performed by the front motor 2, thereby improving the electric power consumption of the vehicle.

[0048] (Control of heat generation during charging) Next, the operation of the heat generation control in a state (charging mode) in which the vehicle 100 is charging and stopped will be described with reference to Fig. 5. Fig. 5 is a schematic diagram showing a state in which the vehicle according to the first embodiment is charging while stopped. In the charging mode shown in Fig. 5, as in the above-mentioned stopped state, the brake pedal 53 is depressed and the brake 9 is ON (locked) (BRK ON), or even if the brake pedal 53 is not depressed, the brake 9 of the vehicle 100 is ON (locked) by brake hold or the like, or other brakes (so-called parking brakes or side brakes) not shown are ON (locked), and the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR of the vehicle 100 are forcibly fixed.

[0049] As described above, it is difficult to charge the battery unit 20 at low temperatures. Therefore, in this charging mode, the purpose is to warm up the battery unit 20 in particular with the power of the charger 200 so that the battery unit 20 can be charged by the charger 200.

[0050] When the control unit 10 determines the charging mode through the vehicle state control and determines that the heat generation control is ON through the ON / OFF control of the heat generation control, as shown in Figure 5, it powers the front motor 2 using the power of the charger 200 so that the front motor 2 generates a backward driving force TF1 as a first counteracting driving force Tcan1 at the left and right front wheels 7FL, 7FR, and powers the rear motor 3 using the power of the charger 200 so that, while synchronized with the front motor 2, the rear motor 3 generates a forward driving force TR1 as a second counteracting driving force Tcan2 that is the same magnitude as the driving force TF1 of the front wheels 7FL, 7FR.

[0051] As in the case of stopping the vehicle, it is safer for the driving force TF1 of the front wheels 7FL, 7FR output by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR output by the rear motor 3 to be smaller than the braking force that stops the rotation of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR by turning on the brake 9, but since the driving forces TF1 and TR1 cancel each other out, they may be larger than the braking force of the brake 9. Also, when the rotation speeds of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR are detected by an ABS sensor (not shown) or the like and it is determined that the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR are not rotating, it is preferable to permit the driving of the front motor 2 and the rear motor 3 by this heat generation control, and to stop the driving of the front motor 2 and the rear motor 3 when the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR rotate due to slippage, for example.

[0052] In addition, in this charging mode, if the driving force TF1 on the front wheels 7FL, 7FR by the front motor 2 and the driving force TR1 on the rear wheels 7RL, 7RR by the rear motor 3 are the same as those during the stop state, it is possible to perform simple control of simply switching the power supply source from the charger 200 to the battery unit 20 when charging is terminated and the vehicle transitions to the stop mode. However, this is not limited to the above, and since the charging mode can accept power from the charger 200 that is greater than the output performance of the battery unit 20, such as in quick charging, the driving forces generated in the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR may be made larger than in the stop mode, and in this case the warm-up period can be shortened.

[0053] In addition, in this charging mode, as in the stop mode described above, the front motor 2 and the rear motor 3 are powered and controlled, i.e., no power is generated by regeneration of the front motor 2, so the compressor 30 is not driven; however, the compressor 30 may be driven using power from the charger 200 to heat the interior of the vehicle.

[0054] As described above, even in heat generation control in charging mode, by outputting the driving force TF1 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR by the rear motor 3 so as to cancel each other out in the direction of travel of the vehicle 100, it is possible to pass a larger current through the front motor 2 and the rear motor 3 than when current is passed through, for example, a single-phase coil. This makes it possible to increase the amount of heat generated during warm-up and shorten the warm-up time.

[0055] (Heat generation control while reversing) Finally, the operation of the heat generation control in a state where the vehicle 100 is accelerating or running steadily while traveling backward (reverse mode) will be described with reference to Fig. 6. Fig. 6 is a schematic diagram showing a state when the vehicle according to the first embodiment is accelerating while traveling backward. In the reverse mode shown in Fig. 6, the brake pedal 53 is not depressed and the brake 9 is OFF (released) (BRK OFF), and other brakes (not shown, so-called parking brakes and side brakes) are also OFF (released), and the left and right front wheels 7FL, 7FR and the left and right rear wheels 7RL, 7RR of the vehicle 100 are rotatable.

[0056] In this heat generation control during acceleration and steady driving while traveling in reverse, the roles (relationship) of the front motor 2 and the rear motor 3 are reversed compared to the heat generation control during acceleration and steady driving while traveling forward described above (see Figure 3).

[0057] That is, when the control unit 10 determines the reverse mode through the vehicle state control and determines that the heat generation control is ON through the heat generation control ON / OFF control, and determines that there is a required driving force Trq based on the accelerator opening degree of the accelerator pedal 52, etc., it controls the front motor 2 using the power of the battery unit 20 so that the front motor 2 generates a reverse driving force TF4, which is the sum of the first counteracting driving force Tcan1 and the required driving force Trq, to ​​the left and right front wheels 7FL, 7FR, as shown in Figure 6, and regeneratively controls the rear motor 3 so that the rear motor 3 generates a forward driving force TR4 as a second counteracting driving force Tcan2 to the left and right rear wheels 7RL, 7RR, while synchronizing with the powering control of the front motor 2.

[0058] Other than this, the operation is the same as the heat generation control during acceleration and steady running in the forward mode (see FIG. 3) except that the operations of the front motor 2 and the rear motor 3 are reversed. Also, although not shown, deceleration during reverse running is the same as the heat generation control during acceleration and steady running in the forward mode (see FIG. 4) except that the operations of the front motor 2 and the rear motor 3 are reversed.

[0059] In this way, in heat generation control during reverse running (driving mode), the driving force TF4 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR4 of the rear wheels 7RL, 7RR by the rear motor 3 are output so as to cancel each other out in the traveling direction of the vehicle 100, which makes it possible to pass a larger current through the front motor 2 and the rear motor 3 than when a current is passed through, for example, a single-phase coil, so that the amount of heat generated during warm-up can be increased and the warm-up time can be shortened. Also, in this heat generation control during reverse running (driving mode), regeneration is performed by the rear motor 3, thereby improving the electric power consumption of the vehicle.

[0060] <Second embodiment> Next, a second embodiment, which is a partial modification of the first embodiment, will be described with reference to Figs. 9 and 10. Fig. 9 is a time chart showing an example of driving when heat generation control according to the second embodiment is executed. Fig. 10 is a time chart showing an example of driving when heat generation control according to a comparative example is executed. In the description of the second embodiment, the same reference numerals are used for parts similar to those of the first embodiment, and the description thereof will be omitted.

[0061] In the vehicle drive device 1 according to the first embodiment described above, the second counteracting drive force Tcan2 is added to the required drive force Trq and output from the rear motor 3 during forward driving while heat generation control is being executed, that is, the vehicle is driven and controlled as a rear-wheel drive type vehicle (see FIG. 3). In the vehicle drive device 1 according to the second embodiment, the first counteracting drive force Tcan1 is added to the required drive force Trq and output from the front motor 2, that is, the vehicle is driven and controlled as a front-wheel drive type vehicle. In this case, the drive force TF2 of the front wheels 7FL, 7FR is output toward the front of the vehicle 100, and the drive force TR2 of the rear wheels 7RL, 7RR is output toward the rear of the vehicle 100.

[0062] In addition, in the vehicle drive device 1 according to the first embodiment described above, while the vehicle is stopped during execution of heat generation control, the driving force TF2 of the front wheels 7FL, 7FR is output toward the rear of the vehicle 100, and the driving force TR2 of the rear wheels 7RL, 7RR is output toward the front of the vehicle 100 (see FIG. 2), but in the vehicle drive device 1 according to the second embodiment, the driving force TF2 of the front wheels 7FL, 7FR is output toward the front of the vehicle 100, and the driving force TR2 of the rear wheels 7RL, 7RR is output toward the rear of the vehicle 100. Note that, in the first embodiment, the stop mode is determined when the vehicle is in the non-driving range, but in the second embodiment, the stop mode is executed when the vehicle speed is 0 even in the forward range.

[0063] (Driving example in comparative example) Here, a driving example in the comparative example will be described with reference to Fig. 10, and a problem in the comparative example will be described. As shown in Fig. 10, for example, when the vehicle 100 is stopped with the forward range selected, and the ECU 10 determines to start the heat generation control at time t21 from the non-operating state of the heat generation control (see S4 in Fig. 7), the heat generation control while stopped is started. Then, the ECU 10 turns on the brake 9 of the vehicle 100 from time t21 to time t22, and turns on the brake 9 by time t22. That is, the brake braking force is increased to a braking force at which the vehicle 100 does not move even if the front motor 2 or the rear motor 3 stops, for example. When the brake 9 is turned ON, the ECU 10 controls the front motor 2 and the rear motor 3 to power the front and rear wheels 7FL, 7FR and the rear wheels 7RL, 7RR, respectively, so that by time t23, the first counteracting driving force Tcan1 is output from the front wheels 7FL, 7FR and the second counteracting driving force Tcan2 is output from the rear wheels 7RL, 7RR, respectively, so that the force directions are opposite to each other in the traveling direction of the vehicle 100 and are the same in magnitude.

[0064] At time t24, for example, when the driver releases the brake pedal 53 and the brake depression amount becomes 0, the ECU 10 determines the driver's intention to start the vehicle 100. As described above, in the heat generation control while the vehicle 100 is traveling, the front motor 2 is powered to output the first counteracting driving force Tcan1 from the front wheels 7FL, 7FR, and the rear motor 3 is regeneratively controlled to generate the second counteracting driving force Tcan2 at the rear wheels 7RL, 7RR. As a result, in the heat generation control while traveling, the regenerative control of the rear motor 3 is used to reduce the amount of power consumed by the heat generation control. However, it is necessary to switch the rear motor 3 from powering control to regenerative control. For this reason, the ECU 10 executes the switching control to transition from the heat generation control when the vehicle is stopped to the heat generation control when accelerating. In this switching control, the application of driving force to the rear wheels 7RL, 7RR is interrupted until the rear motor 3 starts regenerative control, so that the output of driving force by the powering control of the front motor 2 is also stopped to prevent the vehicle 100 from entering an unintended starting state.

[0065] In detail, when the switching control is started at time t24, the ECU 10 stops the output of the driving force of the front motor 2 and the rear motor 3 by time t25. This allows the brake 9 to be turned off, so the ECU 10 turns off the brake 9 by time t26, and makes it possible to start the heat generation control during acceleration. However, if the driver presses the accelerator pedal 52 and the accelerator opening degree increases between time t24 and t26, the required driving force Trq increases accordingly. At time t26, the ECU 10 starts the powering control of the front motor 2 and starts the regenerative control of the rear motor 3 in order to meet the required driving force Trq, and controls so that the sum of the driving force TF1 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR by the rear motor 3 becomes the driving force that meets the required driving force Trq by time t27. As a result, the vehicle 100 starts moving from time t26, and the vehicle speed of the vehicle 100 increases.

[0066] However, in this comparative example, an elapsed time TB elapses from when the driver's intention to start is determined at time t24 until heat generation control during acceleration can be started, that is, until time t26 when it is determined that the vehicle 100 will start. This causes a delay between when the driver attempts to start the vehicle 100 and when the vehicle 100 actually starts, which causes a problem of discomfort to the driver.

[0067] (Driving example in the second embodiment) Next, the execution of heat generation control in the second embodiment will be described with reference to FIG. 9. In the second embodiment, the ECU 10 detects, for example, by the camera 61 (see FIG. 1), that the traffic light has changed from red to green, or that the preceding vehicle has started, and detects a state in which the vehicle 100 can start, that is, predicts and judges the start of the vehicle 100. Note that information indicating the state of the traffic light may be acquired by a TSPS (Traffic Signal Prediction Systems) or a system such as an ITS (Intelligent Transport Systems). In other words, information on the state of the traffic light may be acquired in any way, not limited to an image captured by the camera 61. In addition, the start of the preceding vehicle may be detected by, for example, a millimeter wave radar or a laser detector, or information may be acquired by a system such as an ITS. In other words, information on the start of the preceding vehicle may be acquired in any way, not limited to an image captured by the camera 61.

[0068] As shown in FIG. 9, for example, when the vehicle 100 is stopped with the forward range selected, the ECU 10 determines at time t11 to start the heat generation control from the non-operating state of the heat generation control (see S4 in FIG. 7), and starts the heat generation control when the vehicle is stopped. Then, the ECU 10 turns on the brake 9 of the vehicle 100 from time t11 to time t12, and turns on the brake 9 by time t12. That is, the brake braking force is increased to a braking force that does not move the vehicle 100 even if the front motor 2 or the rear motor 3 stops. When the brake 9 is turned on, the ECU 10 performs power running control on the front motor 2 and the rear motor 3, and by time t13, the first counteracting driving force Tcan1 is output from the front wheels 7FL, 7FR, and the second counteracting driving force Tcan2 is output from the rear wheels 7RL, 7RR, so that they are opposite to each other in the traveling direction of the vehicle 100 and have the same magnitude.

[0069] For example, at time t14, the ECU 10 predicts and determines whether the vehicle 100 will start moving when, for example, a traffic light changes from red to green. The ECU 10 then starts switching control to transition from heat generation control when the vehicle is stopped to heat generation control when accelerating. When the switching control starts at time t14, the ECU 10 stops the output of driving force from the front motor 2 and the rear motor 3 by time t15. This makes it possible to turn off the brake 9, so the ECU 10 starts turning off the brake 9.

[0070] On the other hand, for example, when the driver releases the brake pedal 53 at time t16 and the brake depression amount becomes 0, the ECU 10 determines that the driver intends to start the vehicle 100. However, since the turning-off of the brake 9 has started at time t15, which is prior to time t16, the brake 9 will be turned off by time t17, and the heat generation control during acceleration can be started.

[0071] Then, for example, at time t17, when the driver depresses the accelerator pedal 52 and the accelerator opening increases, the required driving force Trq increases accordingly. In order to respond to the required driving force Trq at this time t17, the ECU 10 starts powering control of the front motor 2 and starts regenerative control of the rear motor 3, so that the increase in the accelerator opening and the required driving force Trq stops by time t18, and by time t19, the sum of the driving force TF1 of the front wheels 7FL, 7FR by the front motor 2 and the driving force TR1 of the rear wheels 7RL, 7RR by the rear motor 3 becomes a driving force responding to the required driving force Trq.

[0072] As described above, in the second embodiment, a state in which the vehicle 100 is able to start is detected (time t14) before the driver's operation indicating the intention to start (releasing the brake pedal 53) is detected (time t16). Therefore, the elapsed time TA from the operation indicating the intention to start to the start of the vehicle 100 can be made shorter than the elapsed time TB in the comparative example. In other words, the vehicle can respond responsively to the driver's intention, and the driver can be prevented from feeling uncomfortable.

[0073] Other configurations, operations, and effects of the second embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0074] <Third embodiment> Next, a third embodiment will be described, which is a partial modification of the first embodiment. In the description of the third embodiment, the same reference numerals are used for the same parts as in the first embodiment, and the description thereof will be omitted.

[0075] In the first embodiment, whether to execute heat generation control is determined based on the state of air conditioning, water temperature, battery temperature, etc. (see FIG. 7). In the third embodiment, in addition to these, whether to execute heat generation control is determined based on information from the car navigation system 55, for example. That is, the battery unit 20 cannot be charged (or the charging efficiency is poor) at an extremely low temperature, such as below 0 degrees, and cannot be charged even if regenerative control is performed with the front motor 2 or the rear motor 3 while the vehicle 100 is running. Therefore, it is basically impossible to improve the power consumption without performing regenerative control. For this reason, the heat generation control described above is performed using the power of the battery unit 20. However, even if the temperature of the battery unit 20 rises by executing the heat generation control, that is, the warm-up of the battery unit 20 is completed and charging is possible, if the vehicle 100 does not run thereafter, the power consumption by the amount of the increase in the temperature of the battery unit 20 cannot be recovered, which may lead to a deterioration in the power consumption. Therefore, in the third embodiment, whether to execute heat generation control is determined as follows.

[0076] 1, the car navigation system 55 calculates a route from the current position of the vehicle 100 to the destination, and also calculates an expected arrival time based on the route. That is, the car navigation system 55 calculates the distance on the route from the current position of the vehicle 100 to the destination, and the time to the destination. Then, the ECU 10 obtains at least one of these pieces of information from the car navigation system 55.

[0077] On the other hand, the ECU 10 estimates and calculates the temperature of the battery unit 20 when the vehicle arrives at the destination based on the amount of heat that can be generated per unit time by the front motor 2, the rear motor 3, and the drive circuit 5, the current temperature of the battery unit 20, and information on the thermal resistance generated between each component, and from at least one of the information on the distance to the destination and the time to the destination obtained as described above. When the estimated temperature of the battery unit 20 when the vehicle arrives at the destination is less than 0 degrees, that is, when the ECU 10 determines that the warm-up of the battery unit 20 will not be completed by the time the vehicle arrives at the destination, the ECU 10 determines that the heat generation control will not be executed because the battery unit 20 cannot be charged by regenerative control during driving even if the temperature of the battery unit 20 is increased by executing the heat generation control. This makes it possible to prevent the deterioration of electric power consumption caused by the unnecessary execution of the heat generation control.

[0078] In the third embodiment, the car navigation system 55 calculates the distance and time to the destination, but the present invention is not limited to this. For example, the ECU 10 may acquire information that is calculated by a map application of an external device such as a smartphone. In particular, if the external device is connected via wireless communication or wired communication, the information can be acquired. When the navigation system 55 calculates the distance to the destination, the distance may be the distance of the route or the straight-line distance.

[0079] In the third embodiment, when determining whether or not to execute heat generation control based on the distance to the destination, the determination may be based on a preset distance, such as within 5 km to the destination. In this case, the preset distance may be changed based on the temperature of the battery unit 20, that is, the lower the temperature of the battery unit 20, the longer the preset distance may be corrected.

[0080] Similarly, in the third embodiment, when determining whether or not to execute heat generation control based on the time to the destination, the determination may be based on a preset time, such as within 5 minutes to the destination. In this case, the set time may be changed based on the temperature of the battery unit 20, that is, the lower the temperature of the battery unit 20, the longer the set time may be corrected.

[0081] In addition, in the third embodiment, when calculating an estimated temperature of the battery unit 20 upon arrival at the destination, the calculation may be performed taking into consideration battery characteristics, Win (charge control limit power), and the like.

[0082] In addition, in the above description of the third embodiment, a determination is basically made as to whether or not to execute heat generation control when a destination is set, but this is not limited to the above. For example, if the estimated arrival time at the destination changes during driving after execution of heat generation control has started, or if the temperature of the battery unit 20 does not rise as expected, and it is determined that warm-up will not be completed even if heat generation control is executed during the journey to the destination, the heat generation control being executed may be stopped (aborted).

[0083] Other configurations, operations, and effects of the third embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0084] <Fourth embodiment> Next, a fourth embodiment will be described, which is a partial modification of the first embodiment. In the description of the fourth embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0085] In the above first embodiment, whether or not to execute heat generation control was determined based on the air conditioning state, water temperature, battery temperature, etc. (see FIG. 7). In the present fourth embodiment, in addition to these, whether or not to execute heat generation control is also determined in accordance with conditions that affect the steerability of the vehicle 100.

[0086] In other words, for example, if the steering angle of the front wheels 7FL, 7FR becomes large while heat generation control is being executed while the vehicle 100 is traveling, a larger driving force is applied to the front wheels 7FL, 7FR than when heat generation control is not being executed, which may affect steering performance.

[0087] Therefore, in the fourth embodiment, when a state that affects steerability is detected, the execution of heat creation control is stopped (interrupted).

[0088] Specifically, when the heat generation control is being performed while the vehicle 100 is traveling forward (accelerating, traveling at a low speed, or decelerating), the first counteracting driving force Tcan1 is output from the front wheels 7FL, 7FR by the front motor 2, and the second counteracting driving force Tcan2 is output from the rear wheels 7RL, 7RR by the rear motor 3. In this state, when the steering sensor 56 (see FIG. 1) detects a steering angle of a predetermined turning angle (e.g., 5 degrees) or more, the ECU 10 stops the heat generation control, that is, returns to a normal driving state. As a result, while the vehicle 100 is turning, the first counteracting driving force Tcan1 and the second counteracting driving force Tcan2 generated by the heat generation control disappear, and it is possible to prevent them from affecting the steerability.

[0089] When the steering angle detected by the steering sensor 56 becomes less than a predetermined turning angle from a state in which the heat generation control is stopped, the heat generation control is started and restored. At this time, it is desirable to set the steering angle at which the heat generation control is restored to a smaller angle (e.g., 3 degrees) than the predetermined turning angle (e.g., 5 degrees) when the heat generation control is stopped so as not to cause hunting.

[0090] Also, in the above control, the determination to stop the heat generation control has been described according to the steering angle detected by the steering sensor 56. However, this is not limiting, and the ECU 10 may obtain information from the car navigation system 55, and from that information, detect a curve on the route along which the vehicle 100 will travel in which the steering angle will be equal to or greater than a predetermined turning angle, as a state in which steerability will be affected, and make a determination to stop the heat generation control based on that detection.

[0091] Also, in the above control, the heat generation control is stopped when a state that affects steerability is detected (a turning angle of a predetermined value or more is detected by the steering sensor 56, or a curve is detected by the car navigation system 55). However, this is not limiting, and for example, the first counteracting driving force Tcan1 output from the front wheels 7FL, 7FR by the front motor 2 and the second counteracting driving force Tcan2 output from the rear wheels 7RL, 7RR by the rear motor 3 may be limited to a predetermined driving force or less so as to be smaller than that of normal heat generation control.

[0092] As described above, in the fourth embodiment, when a condition that affects steerability is detected, the execution of heat generation control is stopped or the first cancellation driving force and the second cancellation driving force are limited, thereby preventing the execution of heat generation control from affecting steerability while the vehicle 100 is turning.

[0093] Other configurations, operations, and effects of the fourth embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0094] <Fifth embodiment> Next, a fifth embodiment will be described, which is a partial modification of the first embodiment. In the description of the fifth embodiment, the same reference numerals are used for the same parts as in the first embodiment, and the description thereof will be omitted.

[0095] In the above first embodiment, the decision as to whether to execute heat generation control was made based on the air conditioning state, water temperature, battery temperature, etc. (see FIG. 7). In the present fifth embodiment, in addition to these, the decision as to whether to execute heat generation control is also made in response to the selection of a mode by the mode select switch 54 of the vehicle 100.

[0096] That is, for example, the vehicle 100 is configured to be able to select one mode from a plurality of modes including a normal mode in which a first acceleration characteristic is set as the acceleration characteristic of the vehicle 100, and a sport mode in which a second acceleration characteristic that realizes a more dynamic driving than the first acceleration characteristic is set as the acceleration characteristic of the vehicle, by the mode select switch 54. That is, when the sport mode is selected, the output of the front motor 2 and the rear motor 3 with respect to the accelerator opening of the accelerator pedal 52 is configured to be larger than when the normal mode is selected. As a result, when the driver wants to drive the vehicle 100 agilely, that is, to perform so-called sport driving, the driver can select the sport mode by the mode select switch 54 and change the characteristics (behavior) of the vehicle 100 to a state in which steep driving with a direct feeling is possible. However, if the heat generation control as described above is performed in such a sport mode, there is a risk that the behavior of the vehicle 100 will be affected.

[0097] Therefore, in the fifth embodiment, when the normal mode is selected by the mode select switch 54 (when the acceleration characteristics of the vehicle 100 are in the normal mode), the heat generation control is made executable, and when the sports mode is selected (when the acceleration characteristics of the vehicle 100 are in the sports mode), the execution of the heat generation control is stopped. Note that in this embodiment, the modes are described as having a sports mode and a normal mode, but other modes such as an eco mode may also be included. However, even in the eco mode, the warm-up of the vehicle 100 is completed sooner when the heat generation control is executed, and the battery unit 20 can be charged, which enables regenerative control by the front motor 2 and the rear motor 3 to be performed sooner, and it is considered that the electricity consumption is improved overall.

[0098] In this way, in the fifth embodiment, when the vehicle 100 is set to the sports mode, the execution of heat generation control is stopped, which means that it is possible to prevent the behavior of the vehicle 100 from being affected by the execution of heat generation control while driving when the acceleration characteristics of the vehicle 100 are in the sports mode.

[0099] Other configurations, operations, and effects of the fourth embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0100] Sixth embodiment Next, a sixth embodiment will be described, which is a partial modification of the first embodiment. In the description of the sixth embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0101] In the first embodiment described above, whether or not to execute heat generation control was determined based on the air conditioning state, water temperature, battery temperature, etc. (see FIG. 7), but in the sixth embodiment, in addition to these, whether or not to execute heat generation control is also determined based on whether or not there is something (a vehicle, a person, a bicycle, etc.) approaching the vehicle 100.

[0102] That is, for example, when the vehicle 100 is performing heat generation control during charging (see FIG. 5), the brake 9 is turned on with no driver on board, the front motor 2 outputs a first counteracting driving force Tcan1 from the front wheels 7FL, 7FR, and the rear motor 3 outputs a second counteracting driving force Tcan2 from the rear wheels 7RL, 7RR. If some abnormality occurs, for example, and the braking force of the brake 9 becomes small or the first counteracting driving force Tcan1 or the second counteracting driving force Tcan2 becomes large, the vehicle 100 may move. At this time, it is desirable to prevent the vehicle 100 from coming into contact with nearby objects.

[0103] Therefore, in the sixth embodiment, when an object (for example, a vehicle, a person, a bicycle, etc.) approaching the periphery of the vehicle 100 is detected, the execution of the heat creation control is stopped (interrupted).

[0104] Specifically, for example, when the vehicle 100 is performing heat generation control during charging, the ECU 10 analyzes an image captured by the camera 61 or detects an object using the corner sensor 62, and determines that an object has approached within a predetermined distance (e.g., 0.5 to 2 m) of the vehicle 100, and determines to stop the heat generation control. This makes it possible to prevent the vehicle 100 from moving due to the heat generation control even if some abnormality occurs, and to prevent the vehicle 100 from moving and coming into contact with an approaching object. Note that when the ECU 10 determines using the camera 61 or the corner sensor 62 that the object has moved away beyond the predetermined distance, it resumes the heat generation control. This makes it possible to continue the heat generation control during charging.

[0105] Other configurations, operations, and effects of the sixth embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0106] Seventh embodiment Next, a seventh embodiment will be described, which is a partial modification of the first embodiment. In the description of the seventh embodiment, the same reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

[0107] In the above first embodiment, whether or not to execute heat generation control was determined based on the air conditioning state, water temperature, battery temperature, etc. (see FIG. 7). In the present seventh embodiment, in addition to these, whether or not to execute heat generation control is also determined depending on whether or not the vehicle 100 is in a towing state in which it is towing another vehicle or a towing object such as luggage.

[0108] That is, for example, when the vehicle 100 is in a towing state as described above, the vehicle travels under conditions in which a high load is generated on the front motor 2 and the rear motor 3, and there is a risk of an even higher load being generated when traveling uphill, for example. Also, even when the vehicle 100 decelerates, the inertial force of the towing object is generated, so the braking force required by the brake 9 increases. For this reason, if heat generation control is executed in a towing state, an unexpected load is generated, and the durability of the vehicle 100 may be affected.

[0109] Therefore, in the seventh embodiment, when the ECU 10 determines that the vehicle 100 is in a towing state, the ECU 10 stops (suspends) the execution of the heat creation control.

[0110] Specifically, the ECU 10 constantly calculates the running resistance according to the required driving force and the vehicle speed according to the accelerator opening. In other words, the front motor 2 and the rear motor 3 are controlled to be driven so that the total driving force of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR is output as the required driving force. However, if the rate of increase in the vehicle speed that should increase according to the required driving force is low, the running resistance is calculated to be large, and when it is determined that the value of this running resistance exceeds a threshold value, it is determined that the vehicle is in a towing state. Then, when it is determined that the vehicle is in a towing state, the heat generation control is stopped so as not to be executed. This makes it possible to prevent a large load from being generated on the vehicle 100 and to improve durability. In addition, in the towing state, since a high load is applied to the front motor 2 and the rear motor 3 in the first place, the vehicle 100 can be warmed up quickly without executing the heat generation control.

[0111] Other configurations, operations, and effects of the seventh embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0112] <Possibilities for other embodiments> In the above description of the first to seventh embodiments, the front motor 2 has been described as the first rotating electric machine and the rear motor 3 as the second rotating electric machine, but the opposite is also possible, that is, the first rotating electric machine is drivingly connected to one of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR of the vehicle 100, and the second rotating electric machine is drivingly connected to the other of the front wheels 7FL, 7FR and the rear wheels 7RL, 7RR of the vehicle 100. Specifically, the roles of the front motor 2 and the rear motor 3 may be reversed, such as outputting driving force in the vehicle's traveling direction (described in detail later) or switching between power running and regeneration.

[0113] In the first embodiment, the heat generation control is executed in all states of the vehicle 100, including when the vehicle is stopped, when the vehicle is traveling forward, when the vehicle is charging, when the vehicle is traveling backward, etc. However, as long as the heat generation control is executed in some of these states, the heat generation control may not be executed in other states. In particular, the heat generation control is executed even during backward traveling, but since the backward traveling is used less frequently in terms of time than other traveling states, the heat generation control may not be executed in the backward mode.

[0114] In addition, in the first to seventh embodiments, there are no particular limitations on the size or performance of the front motor 2 and the rear motor 3, but the size and performance of these motors may differ as long as the driving forces can be cancelled out.

[0115] In addition, the vehicle 100 described in the first to seventh embodiments is described as not being equipped with a heater (such as a high-voltage heater) that directly warms the coolant or the battery unit 20, but this is not the only option and does not exclude the inclusion of such a heater. When such a heater is installed, it is possible to improve the power consumption by supplying the heater with electric power regenerated by the front motor 2 during heat generation control during forward driving, or electric power regenerated by the rear motor 3 during heat generation control during reverse driving.

[0116] Furthermore, in the first to seventh embodiments, the vehicle 100 has been described as an example of a so-called four-wheel drive electric vehicle in which the front wheels 7FL, 7FR are driven by a front motor 2 and the rear wheels 7RL, 7RR are driven by a rear motor 3. However, the present invention is not limited to this. For example, even if one or both of the front and rear wheels are configured with a hybrid drive device using an engine and a motor (rotating electric machine) as a drive source, the motor of the hybrid drive device can be used as a first rotating electric machine or a second rotating electric machine to output a first cancellation drive force or a second cancellation drive force. [Explanation of symbols]

[0117] 1...vehicle drive device / 2...front motor (first rotating electric machine) / 3...rear motor (second rotating electric machine) / 7FL, 7FR...front wheels / 7RL, 7RR...rear wheels / 10...control unit / 100...vehicle / Tcan1...first counteracting driving force / Tcan2...second counteracting driving force / Tdec...required deceleration force / Trq...required driving force

Claims

1. a first rotating electric machine drivingly connected to one of the front wheels and the rear wheels of the vehicle; a second rotating electric machine that is driven independently of the first rotating electric machine and is drivingly connected to the other of the front wheels and the rear wheels; a control unit that controls the first rotating electric machine and the second rotating electric machine, When executing heat generation control for warming up the vehicle, the control unit controls the first rotating electric machine to generate a first counteracting driving force, and controls the second rotating electric machine to generate a second counteracting driving force acting on a side opposite to the first counteracting driving force in a traveling direction of the vehicle. A drive unit for a vehicle.

2. When executing the heat generation control while the vehicle is traveling, the control unit generates the second counteracting driving force from the second rotating electric machine by powering control of the second rotating electric machine, and generates the first counteracting driving force from the first rotating electric machine by regenerative control of the first rotating electric machine. The vehicle drive device according to claim 1 .

3. When executing the heat generation control during acceleration of the vehicle, the control unit generates the first counteracting driving force from the first rotating electric machine in response to a required driving force, while generating a driving force greater than the second counteracting driving force from the second rotating electric machine, thereby causing the vehicle to run. The vehicle drive device according to claim 2 .

4. When executing the heat generation control during deceleration of the vehicle, the control unit controls the first counteracting driving force generated from the first rotating electric machine and the second counteracting driving force generated from the second rotating electric machine to be equal in magnitude, and activates a brake device of the vehicle in accordance with a required deceleration force to decelerate the vehicle. The vehicle drive device according to claim 2 .

5. The control unit is When the heat generation control is executed while the vehicle is stopped, the first rotating electric machine is powered to generate the first counteracting driving force from the first rotating electric machine, and the second rotating electric machine is powered to generate the second counteracting driving force having the same magnitude as the first counteracting driving force from the second rotating electric machine, When a state in which the vehicle can start is detected while the vehicle is stopped, execution of the heat generation control is stopped. The vehicle drive device according to claim 2 .

6. The control unit acquires at least one of information on a distance and a time until the vehicle arrives at the destination, and when it is determined that the warm-up of the vehicle will not be completed by the time the vehicle arrives at the destination, stops the execution of the heat generation control. The vehicle drive device according to claim 2 .

7. When the control unit detects a state that affects the steerability of the vehicle, the control unit stops execution of the heat generation control or limits the first counteracting drive force and the second counteracting drive force. The vehicle drive device according to claim 2 .

8. The control unit is acquiring mode information including a normal mode in which a first acceleration characteristic is set as the acceleration characteristic of the vehicle, and a sports mode in which a second acceleration characteristic that realizes a more dynamic driving than the first acceleration characteristic is set as the acceleration characteristic of the vehicle; The heat generation control can be executed when the normal mode is selected. Stopping the execution of the heat generation control when the sports mode is selected. The vehicle drive device according to claim 2 .

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