Vehicle Control Systems

Abstract

The present invention realizes a redundant structure with continuity of operation in the event of a fault at a lower cost and safely performs switching of power sources. The vehicle control system of the present invention comprises: a first motor that drives the vehicle; a second motor that generates electricity using the output of the power source and starts the power source; a power storage device that stores the electricity generated by the second motor and supplies electricity to the first motor; a monitoring device that monitors the fault state of the vehicle; and a driving force switching device that switches the driving force for driving the vehicle from the first motor to the second motor. When a fault of the first motor is detected and the driving force is obtained from the second motor in a specified operating state, the monitoring device controls the switching device to switch the driving force for driving the vehicle from the first motor to the second motor.

Description

Technical Field

[0001] The present invention relates to a vehicle control system for running a vehicle using electric power generated by an engine. Background Art

[0002] One of the safety requirements for advanced automated driving is fail-safe operation (failure-time operation continuation), which is to maintain minimum performance using the remaining functions instead of stopping the function when a component fails.

[0003] In autonomous vehicles, it is required to ensure system safety through redundancy of control systems and sensor systems, and to automatically and safely stop the vehicle when it becomes difficult to continue autonomous driving.

[0004] The driving control system that realizes automatic driving is composed of a sensing unit, a computing unit, and a driving unit. The sensing unit identifies surrounding vehicles, pedestrians, and driving roads, the computing unit formulates a driving plan based on the sensed information, and the driving unit is an engine, motor, etc., which generates the driving force of the vehicle. In order to stop the vehicle after moving to a safe place even if a failure occurs, fault handling is required not only for the sensing unit and computing unit, but also for the failure of the vehicle's driving system.

[0005] As a vehicle drive system, a series hybrid drive system using the power generated by the engine to generate driving force is becoming popular in order to improve the efficiency of the engine brought about by constant speed driving dedicated to power generation and to ensure a sufficient driving distance. The main components of the drive system are an engine for power generation, a generator, an electric motor, and a battery. As a drive system for such a hybrid vehicle, Patent Document 1 discloses.

[0006] Patent document 1 includes: an electric generator that is driven by an engine to generate an AC current and also functions as a starter that drives the engine when starting a vehicle; a motor that drives the vehicle; a diode rectifier that rectifies the AC current generated by the electric generator; a first converter that is connected to a power supply path between the diode rectifier and the motor and converts the DC current of the power supply path into an AC current; a second converter that is connected in parallel with the first converter; a battery that is connected to the power supply path; and a switch unit that can selectively switch to one of a motor power supply mode and a starter power supply mode, wherein the motor power supply mode is to connect the second converter to the motor and the starter power supply mode is to connect the battery to the electric generator via the second converter. Thus, effective use of the converter and high-efficiency operation are achieved.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2009-29395 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] According to the conventional technology, effective utilization and high efficiency of the converter can be achieved, but more consideration is desired in redundancy of the control device and failure operation.

[0012] Therefore, an object of the present invention is to realize a redundant configuration with operation continuity in the event of a failure in a hybrid vehicle drive system at a lower cost and to safely perform switching of power sources.

[0013] Technical means of solving problems

[0014] The vehicle control system of the present invention comprises: a first motor that drives the vehicle; a second motor that generates electricity using the output of a power source and starts the power source; a power storage device that stores the electricity generated by the second motor and supplies the electricity to the first motor; a monitoring device that monitors the fault state of the vehicle; and a driving force switching device that switches the driving force for driving the vehicle from the first motor to the second motor. When the monitoring device detects a fault in the first motor and is in a specified operating state in which the driving force is obtained from the second motor, the switching device controls the switching device to switch the driving force for driving the vehicle from the first motor to the second motor.

[0015] Effects of the Invention

[0016] According to the present invention, a vehicle control system can be provided that realizes a low-cost redundant structure in which a second electric motor as a generator is used as a power source when a first electric motor for driving fails, and ensures safety. Other issues, structures and effects will be clarified through the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The first embodiment of the present invention is shown in the figure, which shows an example of a hybrid drive system.

[0018] Figure 2 The diagram shows a case where the present invention is not applied, and shows the vehicle speed and the state of the electric motor of the hybrid drive system.

[0019] Figure 3 The first embodiment of the present invention is shown in the diagram showing the vehicle speed and the state of the electric motor of the hybrid drive system.

[0020] Figure 4Embodiment 1 of the present invention is shown as a graph showing the relationship between the rotation speed and torque of a motor.

[0021] Figure 5 The first embodiment of the present invention is shown in a graph showing the relationship between the vehicle speed, the rotation speed of the wheels, and the rotation speed of the motor.

[0022] Figure 6 A diagram showing a modified example of the first embodiment of the present invention, showing the relationship between the motor and the clutch.

[0023] Figure 7 A modified example of the first embodiment of the present invention is shown, which is a graph showing the relationship between the rotation speed and torque of the motor.

[0024] Figure 8 The second embodiment of the present invention is shown in the figure, which shows an example of a hybrid drive system.

[0025] Fig. 9 A modified example of the second embodiment of the present invention is shown, which is a diagram showing the relationship between the motor and the clutch. DETAILED DESCRIPTION

[0026] Next, embodiments of the present invention will be described.

[0027] Example 1

[0028] Next, Example 1 of the present invention will be described. Figure 1 An embodiment of a hybrid power drive system using the present invention is shown. Figure 1 The hybrid drive system shown includes a first drive device 1, which is composed of an electric motor M1, an inverter IN1 and a controller MC1. The electric motor M1 applies torque to the wheel 3 according to a torque instruction 4, the inverter IN1 controls the current applied to the electric motor M1, and the controller MC1 controls the speed (or torque) of the electric motor M1.

[0029] The electric motor M1 also includes a function of regenerating energy when the vehicle decelerates, and the regenerated electric energy is converted into direct current by the converter IN1 and stored in the battery BT. When the first drive device operates as a regenerative function, the converter IN1 and the controller MC1 function as an inverter that converts the AC voltage output from the electric motor M1 into a DC voltage to charge the battery BT.

[0030] If the motor M1 is in a normal state, the engine 5 is used for generating electric energy. The rotational force of the engine 5 is converted into an alternating current by the motor M2. The alternating current generated by the motor M2 is converted into a direct current by the controller MC2 and the converter IN2 to charge the battery BT. In addition, the converter IN2 can function as an inverter including a rectifier circuit.

[0031] Furthermore, the electric motor M2 includes a function of generating a starting torque of the engine 5 (starter).

[0032] In this case, the electric motor M2 is included in the second drive device 2 which is constituted by an inverter IN2 which controls the current applied to the electric motor M2 and a controller MC2 which controls the rotation speed (or torque) of the electric motor M2.

[0033] In addition, controller MC1 and controller MC2 are configured by different ICs and are arranged separately. In addition, inverter IN1 and inverter IN2 are configured by different ICs and are arranged separately. By arranging the circuits of controllers MC1 and MC2 and inverters IN1 and IN2 separately, redundancy can be ensured.

[0034] In order to apply the hybrid drive system as described above to a drive system of an autonomous driving vehicle, it is required to create a hybrid drive system in which the redundancy cost for ensuring safety is minimized.

[0035] The hybrid drive system has many parts, so it is necessary to reduce the capacity and function of each part to the minimum necessary to achieve miniaturization and cost reduction. For example, the electric motor M2 can be selected as a low-power product with a small power generation capacity. The reason is that when the required power temporarily increases during acceleration, the electric energy stored in the battery BT can be used.

[0036] In addition, the redundancy of the drive system must be achieved by using the existing hybrid drive system to suppress costs. The hybrid drive system described above includes the first drive device 1 and the second drive device 2, so these drive devices can be used to form a redundant structure as follows.

[0037] When the motor M1 fails, the motor M1 is disconnected from the wheel 3 by the clutch 6a, and the motor M2 is connected to the wheel 3 by the clutch 6b to continue driving. The engine 5 is disconnected from the motor M2 by the clutch 6c. The torque command 4 switches the destination of the torque command from the controller MC1 to the controller MC2 by the signal switch 7. In addition, as described later, the clutches 6a to 6c and the signal switch 7 are controlled by the monitoring device 8.

[0038] The clutch 6 a is used to reduce torque loss caused by a malfunctioning electric motor M1 .

[0039] The clutch 6b only needs to transmit the driving force from the motor M2 whose torque output is smaller than that of the motor M1, so a small and low-cost product can be selected. In addition, the purpose of the clutch 6c is to disconnect the engine 5 from the motor M2 to reduce the torque loss of the motor M2 caused by the engine 5. The clutches 6a to 6c of this embodiment function as a switching device for the driving force that drives the vehicle.

[0040] The clutch 6a and the clutch 6c are used to reduce the loss of torque transmitted to the electric motor M2 by disconnecting the clutch. Even if the engine 5 and the electric motor M1 are connected to the electric motor M2, these clutches are not necessarily essential components as long as the driving force required for the vehicle can be ensured.

[0041] The redundant configuration described above uses the low-power motor M2 when the motor M1 fails, so the driving force during the failure is limited. However, it is a low-cost redundant configuration as long as the minimum driving force required to evacuate the vehicle to a safe place can be ensured.

[0042] In order to judge and instruct the above switching, the hybrid drive system includes a monitoring device 8 to which the present invention is applied. The monitoring device 8 is a device that performs control such that a failure of the first drive device 1 is detected and the drive device 2 is switched safely.

[0043] For example, a signal from a vehicle speed sensor 11 that detects the vehicle speed based on the rotation speed (rotation speed per unit time) of the wheels 3 is input to the monitoring device 8 to detect the speed of the vehicle (vehicle speed). The monitoring device 8 is a computer including a CPU 81 and a memory 82. A control program (PGM in the figure) 83 is loaded into the memory 82 and executed by the CPU 81.

[0044] The control program 83 monitors the current of the electric motor M1 to detect a failure, and when a failure is detected, controls the clutches 6a to 6c and the signal switch 7 based on the value of the vehicle speed sensor 11 to switch to running by the electric motor M2.

[0045] Furthermore, in this embodiment, the example in which the motor M1 has a current sensor and the control program 83 of the monitoring device 8 obtains the value of the current sensor and detects a fault when the current of the motor M1 is cut off (or reduced) is shown, but the present invention is not limited to this. For example, the motor M1 may also have a fault detection device (not shown) that monitors the current or driving state to detect a fault, and when a fault occurs, the fault detection device notifies the monitoring device 8 of the occurrence of the fault. In addition, as the vehicle speed sensor 11, a wheel speed sensor that detects the rotation speed of the wheel, an acceleration sensor, a satellite positioning system, etc. may be used.

[0046] use Figure 2 , Figure 3The traveling state when a failure occurs in the electric motor M1 will be described. Figure 2 The graph is a graph showing the vehicle speed curve and the motor states when the present invention is not applied. As an example, the graph shows the driving states of the motors M1 and M2 and the vehicle speed when the motor M1 fails while the vehicle is traveling at 100 km / h.

[0047] When the vehicle is traveling at 100 km / h, the driving force of the motor M1 causes the vehicle to travel, and the motor M2 is driven by the engine 5 to generate electricity. Here, it is assumed that when a failure occurs in the motor M1, the monitoring device 8 detects the failure and engages the clutch 6b to connect the motor M2 to the wheel 3. In this case, the rotational force of the wheel 3 is applied to the motor M2, causing it to rotate at a high speed.

[0048] When the electric motor M2 rotates due to an external force, it enters a power generation (regeneration) state, and the vehicle speed is suddenly reduced due to the resistance of the electric motor M2 in the power generation state.

[0049] When the vehicle speed becomes below a certain speed Vt, the driving force of the motor M2 is obtained, and the vehicle is in a low-speed driving state. If the vehicle speed is suddenly reduced like this, there is a concern that the following vehicle may rear-end or the vehicle may skid. In addition, the sudden deceleration caused by the motor M2 will put a load on the weak clutch 6c, which may cause a malfunction.

[0050] Figure 3 The present invention is a graph showing the driving states of the motors M1 and M2 and the vehicle speed curve when the motor M1 fails in the hybrid drive system including the monitoring device 8 of the present invention. When the vehicle is traveling at 100 km / h, the vehicle is traveling by the driving force of the motor M1 before time T1, and the motor M2 is in the power generation state.

[0051] At time T1, when the motor M1 fails, the monitoring device 8 detects the failure and disconnects the motor M1 from the wheels 3 by releasing the clutch 6a. The vehicle after time T1 runs under inertia and gradually decelerates due to running resistance.

[0052] Then, at time T2 when the vehicle speed decreases to the predetermined vehicle speed Vt, the monitoring device 8 connects the clutch 6b to connect the motor M2 to the wheels 3. In addition, at time T2, the monitoring device 8 releases the clutch 6c to disconnect the engine 5 from the motor M2. Thus, the driving force of the motor M2 can be controlled by the controller MC2 via the inverter IN2. In addition, the operation of the engine 5 can be continued.

[0053] If the vehicle speed is below a certain speed Vt, the driving force of the motor M2 is obtained, so low-speed driving can be achieved after time T2. Through the function of the monitoring device 8, appropriate braking operation is performed without sudden deceleration of the vehicle, thereby decelerating the vehicle and retreating to a safe place while ensuring safety. In addition, the braking operation can be performed by an automatic driving control unit not shown.

[0054] Furthermore, Figure 3 , the example of releasing the clutch 6c and disconnecting the engine 5 from the motor M2 at the time T2 when the motor M2 is started to be driven is shown, but the present invention is not limited to this. For example, the clutch 6c can be released during the period from the time T1 when the motor M1 failure is detected to the time T2 when the clutch 6b is connected. When the monitoring device 8 releases the clutch 6c at the time T2, the battery BT can be charged during the inertial travel.

[0055] The reason why sudden braking is applied when the clutch 6 b is engaged and the power is switched to the electric motor M2 while the vehicle is traveling at a high speed will be described. Figure 4 It is a graph showing the relationship between the rotation speed and the maximum torque of the electric motor M1 and the electric motor M2.

[0056] The torque of the electric motor M1 has a characteristic that the torque decreases as the rotation speed increases. This is because the back electromotive force increases due to the high speed rotation of the electric motor M1, and the driving current for running can no longer flow.

[0057] The maximum torque of the motor M2 is lower than that of the motor M1 because it is a low-power motor. The range of the driving torque (positive torque) obtained by the motor M2 to drive the vehicle is up to the speed Nt. If the speed becomes higher than Nt due to external force, it becomes the power generation area, thereby generating a deceleration torque (negative torque).

[0058] Therefore, if the vehicle is running at high speed when the motor M1 fails and the motor M2 is switched, the rotation speed of the motor M2 exceeds Nt, and the motor M2 enters the power generation region and generates deceleration torque. The higher the vehicle speed, the more rapid the deceleration.

[0059] In order to avoid the above-mentioned sudden deceleration, in the present invention, in the second drive device 2 including the electric motor M1 (first electric motor) for driving the vehicle and the electric motor M2 (second electric motor) whose power is smaller than that of the electric motor M1, a monitoring device 8 for monitoring the state of the vehicle is included. When the monitoring device 8 detects a failure of the electric motor M1 and the vehicle speed has become lower than the vehicle speed Vt at which positive torque is obtained from the electric motor M2, the vehicle driving is switched to based on the electric motor M2.

[0060] Furthermore, when the vehicle speed is low (Vt or less) and the rotation speed of the motor M2 when switching to the motor M2 is Nt or less, the motor M1 may be switched to the motor M2 at the time of failure of the motor M1.

[0061] Thus, safe fail-safe operation can be achieved even when using the low-power, low-cost electric motor M2 and the small clutch 6 b , thereby achieving both miniaturization and cost reduction and redundancy of the hybrid drive system.

[0062] Whether the motor M2 is in the positive torque range when the motor M1 fails can be calculated based on the vehicle speed and the rotation speed of the wheels. Figure 5 It is a graph showing an example of the relationship between the vehicle speed, the rotation speed of the wheels, and the rotation speed of the electric motor M2.

[0063] The relationship between them can be calculated from the diameter of the wheel and the reduction ratio between the motor M2 and the wheel. The rotation speed of the wheel at the rotation speed Nt for obtaining positive torque by the motor M2 is Nt' and the vehicle speed is Vt.

[0064] In order to determine the switching of the driving source when the motor M1 fails, the wheel speed and vehicle speed can be used, and are not limited to any of these values. In addition, the power generation capacity and driving ability of the motor M2 are designed according to the engine and vehicle weight, so the determination of the range (Nt) of obtaining positive torque of the motor M2 is different.

[0065] Figure 6 A diagram showing the relationship between the motor and the clutch is shown in a modification of the first embodiment. In the modification, a hybrid drive system is described in which the range in which the positive torque can be obtained by the motor M2 during running is adjustable. Figure 6 For the general Figure 1 A diagram showing a portion of the vehicle that transmits the driving force of the motor M1 and the motor M2 to the wheels 3. Figure 1 The difference is that a speed converter 9 is provided between the electric motor M2 and the clutch 6b.

[0066] The speed converter 9 may be a combination of a pair of rotating gears or a belt and a pulley. The speed converter 9 increases the speed of the motor M2 to drive the wheel 3. In addition, the speed converter 9 only needs to be arranged between the motor M2 and the wheel 3, for example, it can also be arranged between the clutch 6b and the wheel 3. In addition, the driving force can also be transmitted between the clutch 6b and the wheel 3 through gears. The effect of setting the speed converter 9 is described below.

[0067] Figure 7A graph showing the torque and speed output from the motor M2 via the speed converter 9 is shown. The characteristics of the motor M2 in the figure are different from the speed ratio of the speed converter 9 under the motor M2' shown in the solid line in the figure. As an example, the speed ratio of the characteristics of the motor M2' is set smaller than that of the motor M2. In this embodiment, the speed ratio is set to the input shaft speed / output side speed of the speed converter 9.

[0068] By reducing the speed ratio (less than 1), the speed of the output side of the speed converter 9 increases, so that positive torque can be generated until a higher speed. On the other hand, setting the speed ratio to a smaller value reduces the maximum torque that can be output from the speed converter 9. As long as positive torque can be generated until the high speed area, the driving range of the motor M2 can be widened, thereby suppressing the reduction in vehicle speed when driving at high speed or climbing a slope and making it safer to retreat. As for how much the speed ratio is set, it can be designed according to the weight of the vehicle and the maximum power of the motor M2.

[0069] In the present embodiment, an example in which the motor M1 fails is described, but the above control by the monitoring device 8 can be applied even when any one of the motor M1, the inverter IN1, or the controller MC1 included in the first drive device fails.

[0070] As described above, in the hybrid drive system of the present embodiment, when the electric motor M1 for traveling fails, the electric motor M2 which has been used as a generator is used as a power source, thereby realizing a low-cost redundant configuration.

[0071] In addition, by using an electric motor M2 having a smaller maximum torque than that of the electric motor M1, when a failure occurs in the electric motor M1, the vehicle's operating state becomes gradually decelerated by inertial running until the vehicle reaches a specified condition (vehicle speed is below Vt) under which the electric motor M2 can generate a driving force (positive torque). Thus, a hybrid drive system that ensures safety can be provided.

[0072] In addition, in this embodiment, the example of using the engine 5 as the power source when the electric motor M2 is used as a generator is shown, but it is not limited to this. As the power source of the electric motor M2, an external combustion engine can be used in addition to an internal combustion engine.

[0073] Example 2

[0074] Figure 8 The second embodiment of the present invention is shown in a block diagram showing an example of a hybrid drive system. In the second embodiment, a clutch 6d is arranged between the motor M2 and the motor M1, and when the motor M1 fails, the clutch 6d is engaged to connect the motor M1 and the motor M2.

[0075] The failed electric motor M1 is driven by the driving force of the electric motor M2, and the driving force is applied to the wheels 3 to run the vehicle. The engine 5 is disconnected from the electric motor M2 by the clutch 6c.

[0076] The torque command 4 is transmitted to a destination switched from the controller MC1 to the controller MC2 by the signal switch 7 .

[0077] The clutches 6c, 6d and the signal switch 7 are controlled by the command of the monitoring device 8. The purpose of the clutch 6c is to disconnect the engine 5 from the motor M2 to reduce the torque loss caused by the engine 5. The second embodiment can be applied to the case where the required driving force can be ensured even when the motor M1 that has failed is connected, and the number of clutches can be reduced, resulting in a lower cost structure.

[0078] exist Figure 8 In the structure shown, the range of the vehicle driving force (positive torque) obtained by the electric motor M2 can also be adjusted. Fig. 10 shows a modification of the second embodiment and is a diagram showing the relationship between the electric motor and the clutch.

[0079] Figure 10 is Figure 8 The example shown is a portion where the driving force of the motors M1 and M2 is transmitted to the wheels, and a speed converter 9 is provided between the motor M2 and the clutch 6d. The speed converter 9 may be a combination of a pair of rotating gears or a belt and a pulley.

[0080] Compared with the embodiment 1 Figure 7 As in the structure shown, in the second embodiment, by setting the speed ratio to be smaller (less than 1), the speed on the output side of the speed converter 9 can be increased to generate positive torque at a higher speed, thereby expanding the vehicle speed range that can be driven by the driving force of the electric motor M2.

[0081] In the present embodiment, an example in which the motor M1 fails is described, but the control of the monitoring device 8 can be applied even when any one of the motor M1 , the inverter IN1 , or the controller MC1 included in the first drive device 1 fails.

[0082] As described above, the hybrid drive system of the second embodiment, like the first embodiment, can also realize a low-cost redundant configuration by using the electric motor M2 that has been used as a generator as a power source when the electric motor M1 for driving fails.

[0083] In addition, by using an electric motor M2 having a smaller maximum torque than that of the electric motor M1, when a failure occurs in the electric motor M1, the vehicle's operating state becomes gradually decelerated by inertial running until the vehicle reaches a specified condition (vehicle speed is below Vt) under which the electric motor M2 can generate a driving force (positive torque). Thus, a hybrid drive system that ensures safety can be provided.

[0084] Conclusion

[0085] As described above, the vehicle control system of the above-mentioned embodiment may be configured as follows.

[0086] (1) A vehicle control system, characterized in that it includes: a first electric motor (M1) that drives the vehicle; a second electric motor (M2) that generates electricity using the output of a power source (engine 5) and starts the power source (5); a power storage device (battery BT) that stores the power generated by the second electric motor (M2) and supplies the power to the first electric motor (M1); a monitoring device (8) that monitors the fault state of the vehicle; and a driving force switching device (clutch 6a-6c) that switches the driving force for driving the vehicle from the first electric motor (M1) to the second electric motor (M2), wherein the monitoring device (8) controls the switching device (6a-6c) to switch the driving force for driving the vehicle from the first electric motor (M1) to the second electric motor (M2) when a fault of the first electric motor (M1) is detected and the driving force is obtained from the second electric motor (M2) in a specified operating state.

[0087] With the above configuration, when the motor M1 used for driving fails, the motor M2 previously used as a generator is used as a power source, thereby realizing a low-cost redundant configuration. In addition, by using the motor M2 having a smaller maximum torque than the motor M1, the vehicle is gradually decelerated by inertial driving until the running state of the vehicle in the case of a failure of the motor M1 reaches a predetermined condition (vehicle speed is less than Vt) where the motor M2 can generate a driving force (positive torque), thereby providing a hybrid drive system that ensures safety.

[0088] (2) The vehicle control system according to (1) above is characterized in that it also has a vehicle speed sensor (11) for detecting the vehicle speed, and the monitoring device (8) determines that the vehicle has become the specified operating state when the vehicle speed obtained from the vehicle speed sensor (11) has become below a specified value (Vt), and switches to the driving force from the second motor (M2) to make the vehicle move.

[0089] With the above configuration, the vehicle is gradually decelerated by inertial running until the vehicle speed reaches a predetermined value Vt or less, which is a predetermined condition for generating driving force by the electric motor M2. This provides a hybrid drive system that ensures safety.

[0090] (3) The vehicle control system according to (1) above is characterized in that the first motor (M1) is connected to a first controller (MC1) that controls the current to control the speed, and the second motor (M2) is connected to a second controller (MC2) that controls the current to control the speed, and the first controller (MC1) and the second controller (MC2) are separated into different circuits.

[0091] With the above configuration, the circuits of controllers MC1 and MC2 and inverters IN1 and IN2 are separately arranged, thereby ensuring redundancy against failures and the like.

[0092] (4) The vehicle control system according to the above (1) is characterized in that the switching device (6a~6c) includes: a first clutch (6a), which is arranged between the first motor (M1) and the wheel (3); and a second clutch (6b), which is arranged between the second motor (M2) and the wheel (3), and the monitoring device (8) releases the first clutch (6a) when a failure of the first motor (M1) is detected, and connects the second clutch (6b) when it has become the specified operating state.

[0093] With the above configuration, when the monitoring device 8 detects a failure in the motor M1 , the clutch 6 a is released to disconnect the motor M1 from the wheels 3 , and then the motor M2 is connected to the wheels 3 , thereby preventing sudden deceleration and the like from occurring and safely switching the power source.

[0094] (5) The vehicle control system according to (4) above, characterized in that:

[0095] The switching device (6a-6c) further includes a third clutch (6c) arranged between the second electric motor (M2) and the power source (5), and the monitoring device (8) releases the third clutch (6c) after detecting a failure of the first electric motor (M1).

[0096] With the above configuration, the monitoring device (8) releases the clutch 6c after detecting a failure of the first electric motor (M1), thereby disconnecting the engine 5 from the electric motor M2 and preventing a loss of the driving force generated by the electric motor M2.

[0097] (6) The vehicle control system according to (1) above is characterized in that:

[0098] A rotation speed converter for converting the rotation speed is arranged between the second electric motor (M2) and the wheel (3).

[0099] With the above configuration, the output speed of the speed converter 9 is increased by reducing the speed ratio of the speed converter 9 (less than 1), so that positive torque can be generated at a higher speed. The vehicle speed drop during high-speed travel can be suppressed, and safer evacuation can be performed.

[0100] It should be noted that the present invention includes various modifications and is not limited to the above-described embodiments.

[0101] For example, the above-mentioned embodiments are detailed descriptions for explaining the present invention in an easy-to-understand manner, and are not necessarily limited to having all the described structures. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of a certain embodiment. In addition, a part of the structure of each embodiment can be added, deleted or replaced with other structures alone or in combination.

[0102] In addition, the above-mentioned components, functions, processing units, and processing methods, etc., can be implemented in part or in whole by hardware, for example, by designing with integrated circuits. In addition, the above-mentioned components and functions, etc., can also be implemented in software by interpreting and executing programs that implement the functions by a processor. Information such as programs, tables, and files that implement the functions can be placed in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

[0103] In addition, the control lines and information lines are shown as those considered necessary for explanation, and not all control lines and information lines may be shown on the product. In fact, it can be considered that almost all components are connected to each other.

[0104] Explanation of symbols

[0105] M1…motor, M2…motor, IN1…converter, IN2…converter, MC1…controller, MC2…controller, 1…first drive device, 2…second drive device, 3…wheel, 5…engine, 6a~6d…clutch, 7…signal switch, 8…monitoring device, 9…speed converter, 11…vehicle speed sensor.

Claims

1. A vehicle control system, characterized in that: have: a first electric motor for driving the vehicle; a second electric motor that generates electricity using the output of the power source and starts the power source; a power storage device that stores the power generated by the second electric motor and supplies the power to the first electric motor; a monitoring device that monitors a fault condition of the vehicle; as well as a switching device for switching the driving force for driving the vehicle from the first electric motor to the second electric motor, When a failure of the first motor is detected and the vehicle is in a predetermined operating state where the driving force is obtained from the second motor, the monitoring device controls the switching device to switch the driving force for driving the vehicle from the first motor to the second motor. It also has a vehicle speed sensor for detecting vehicle speed. The monitoring device determines that the predetermined operating state has been reached when the vehicle speed obtained from the vehicle speed sensor has become equal to or less than a predetermined value, and switches the driving force from the second electric motor to cause the vehicle to travel.

2. The vehicle control system according to claim 1, characterized in that: The first motor is connected to a first controller that controls the current to control the rotation speed. The second motor is connected to a second controller that controls the current to control the rotation speed. The first controller and the second controller are separated into different circuits.

3. The vehicle control system according to claim 1, characterized in that: The switching device comprises: a first clutch disposed between the first motor and the wheels; and a second clutch disposed between the second electric motor and the wheel, The monitoring device releases the first clutch when a failure of the first electric motor is detected, and engages the second clutch when the predetermined operating state is reached.

4. The vehicle control system according to claim 3, characterized in that: The switching device further includes a third clutch disposed between the second electric motor and the power source, and the monitoring device releases the third clutch after detecting a failure of the first electric motor.

5. The vehicle control system according to claim 1, characterized in that: A rotation speed converter for converting the rotation speed is arranged between the second electric motor and the wheels.

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