Moving body

Abstract

This invention provides a mobile body that, even if the left and right output units are driven by different drive sources and the mobile body does not have a differential device, can ensure the straight-line stability of the mobile body in the event of slippage in at least one of the left and right output units. The control device (10) performs dual-output unit drive force suppression control when slippage occurs in at least one of the left and right front wheels (FW_L, FW_R) while the left and right motors (FM_L, FM_R) are driving the left and right front wheels (FW_L, FW_R) respectively. That is, it suppresses the drive force of the motor that outputs drive force to the slipping front wheel to suppress slippage, and suppresses the drive force of the motor that outputs drive force to the non-slipping front wheel to the same value as the drive force of the slipping front wheel.

Description

Technical Field

[0001] This invention relates to a mobile body. Background Technology

[0002] In recent years, initiatives aimed at achieving a low-carbon or decarbonized society have been very active as a concrete countermeasure to address global climate change. This includes requirements for reducing CO2 emissions and improving energy efficiency in vehicles such as automobiles; for example, research and development related to electrification technologies such as electric vehicles and hybrid electric vehicles are underway.

[0003] The following technology is disclosed in Patent Document 1: When driving on a high μ road and the braking control requires 2ch control, the braking pressure is independently controlled on the left and right drive wheels in response to the occurrence of acceleration slip; when driving on a low μ road, driving on a split μ road, etc., and the braking control requires 1ch control, the same TCS braking control is performed on the left and right sides based on the left and right average values ​​of the acceleration slip state in response to the occurrence of acceleration slip on the left and right drive wheels.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 2903821 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In moving bodies where the left and right output sections (e.g., wheels) are driven by different drive sources, there are also moving bodies that do not have a differential device (so-called differential gear). In the prior art, from the viewpoint of ensuring straight-line stability in the event of slippage in at least one of the output sections, there is room for improvement in such moving bodies.

[0009] The present invention provides a moving body that, even if the left and right output sections are driven by different drive sources and the moving body does not have a differential device, can ensure the straight-line stability of the moving body in the event that at least one of the left and right output sections slips.

[0010] Solution for solving the problem

[0011] This invention provides a mobile body, wherein,

[0012] The mobile body has:

[0013] The first drive source outputs braking force and driving force to either the left or right output section;

[0014] The second drive source outputs braking and driving forces to the output units on the left and right sides; and

[0015] A control device that controls the first drive source and the second drive source.

[0016] When at least one of the outputs of one party and the other party slips while the first drive source and the second drive source are respectively driving the output of the other party, the control device performs dual output drive force suppression control.

[0017] In the dual-output driving force suppression control, the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively large slippage is suppressed to suppress the slippage, and the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively small slippage or no slippage is suppressed to the same value as the driving force of the output unit that experiences relatively large slippage.

[0018] Invention Effects

[0019] According to the present invention, a moving body can be provided that, even if the left and right output sections are driven by different drive sources and the moving body does not have a differential device, the straight-line stability of the moving body can be ensured in the event that at least one of the left and right output sections slips. Attached Figure Description

[0020] Figure 1 This is a diagram showing a schematic structure of the movable body according to this embodiment.

[0021] Figure 2 This is a block diagram showing the functional structure of the control device mounted on the mobile body in this embodiment.

[0022] Figure 3 This is a diagram showing the outline of the dual-output drive force suppression control performed by the control device in this embodiment.

[0023] Figure 4 This is a flowchart illustrating an example of dual-output drive force suppression control performed by the control device in this embodiment.

[0024] Figure 5 It means Figure 4 The flowchart of the subroutine (Hi_μ round decision processing) in the flowchart.

[0025] Figure 6 It means execution Figure 4 The flowchart shows the timing diagram of the behavior of the motor torque indication value (MOT torque indication) and the drive torque (actual torque) output by the motor during control.

[0026] Figure 7This is a flowchart illustrating another example of dual-output drive force suppression control performed by the control device in this embodiment.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10. Control device

[0029] 11 Main ECU

[0030] 12. Motor ECU (MOT_ECU)

[0031] FM_L, FM_R, RM_L, RM_R Motors (Drive Sources)

[0032] FW_L, FW_R, RW_L, RW_R Wheels (Output Section)

[0033] Se1 Wheel Speed ​​Sensor

[0034] Se2 steering angle sensor

[0035] Se3 AP sensor

[0036] Se4 Lateral Accelerometer (Lateral Accelerometer Acquisition Unit)

[0037] V. Vehicle (moving entity). Detailed Implementation

[0038] The following detailed description of one embodiment of the present invention is based on the accompanying drawings. Furthermore, not all features described in the following embodiments are essential to the present invention. Additionally, two or more features described in the following embodiments can be combined arbitrarily. Hereinafter, the same or similar elements are sometimes labeled with the same or similar reference numerals, and their descriptions are appropriately omitted or simplified.

[0039] First, a vehicle V equipped with a control device (control device 10 described later) as one embodiment of the present invention will be described. The vehicle V of this embodiment is an example of a moving body in the present invention.

[0040] [vehicle]

[0041] Figure 1 The vehicle V shown is a battery electric vehicle (pure electric vehicle) that uses an electric motor as its driving force. Figure 1 In the example shown, vehicle V has left and right front wheels FW_L and FW_R as output units for steering vehicle V, and left and right rear wheels RW_L and RW_R as output units for not steering vehicle V. The left front wheel FW_L and the right front wheel FW_R can also be referred to as the steering wheels in vehicle V.

[0042] In addition, the vehicle V has a motor FM_L as a first drive source that outputs braking force and driving force to the left front wheel FW_L (i.e., the output unit that steers the vehicle V), and a motor FM_R as a second drive source that outputs braking force and driving force to the right front wheel FW_R (i.e., the output unit that steers the vehicle V).

[0043] Furthermore, the vehicle V has a motor RM_L as a third drive source that outputs braking force and driving force to the left rear wheel RW_L (i.e., the output unit of the side that does not steer the vehicle V), and a motor RM_R as a fourth drive source that outputs braking force and driving force to the right rear wheel RW_R (i.e., the output unit of the other side that does not steer the vehicle V).

[0044] Furthermore, the vehicle V is configured to include a control device 10 that independently controls each motor FM_L, FM_R, RM_L, and RM_R.

[0045] Each motor FM_L, FM_R, RM_L, and RM_R is an electric generator that primarily serves as the drive source for vehicle V, and may be composed of, for example, an AC motor. Each motor FM_L, FM_R, RM_L, and RM_R operates as an electric motor by receiving power from a battery (not shown), outputting power for the movement of vehicle V.

[0046] In addition, each motor FM_L, FM_R, RM_L, and RM_R can also act as a generator to generate electricity during vehicle V braking (so-called regenerative power generation). The electricity generated by the regenerative operation of each motor FM_L, FM_R, RM_L, and RM_R is supplied to the battery via a power conversion device (not shown) to charge the battery.

[0047] Motor FM_L is connected to the left front wheel FW_L, and the output of motor FM_L is transmitted to the left front wheel FW_L. Therefore, motor FM_L acts as an electric motor to drive the left front wheel FW_L. In addition, motor FM_L acts as a generator to regenerate electricity, thereby braking the left front wheel FW_L.

[0048] Motor FM_R is connected to the right front wheel FW_R, and the output of motor FM_R is transmitted to the right front wheel FW_R. Therefore, motor FM_R acts as an electric motor to drive the right front wheel FW_R. In addition, motor FM_R acts as a generator to regenerate electricity, thereby braking the right front wheel FW_R.

[0049] Motor RM_L is connected to the left rear wheel RW_L, and the output of motor RM_L is transmitted to the left rear wheel RW_L. Therefore, motor RM_L acts as an electric motor to drive the left rear wheel RW_L. In addition, motor RM_L acts as a generator to regenerate electricity, thereby braking the left rear wheel RW_L.

[0050] Motor RM_R is connected to the right rear wheel RW_R, and the output of motor RM_R is transmitted to the right rear wheel RW_R. Therefore, motor RM_R acts as an electric motor to drive the right rear wheel RW_R. In addition, motor RM_R acts as a generator to regenerate electricity, thereby braking the right rear wheel RW_R.

[0051] In addition, Figure 1 In the example shown, vehicle V is a four-wheel drive electric vehicle where all four wheels—the left and right front wheels FW_L and FW_R, and the left and right rear wheels RW_L and RW_R—are driven by motors FM_L, FM_R, RM_L, and RM_R, respectively. However, it is not limited to this. For example, vehicle V could also be a front-wheel drive electric vehicle where only the left and right front wheels FW_L and FW_R are driven by motors FM_L and FM_R, respectively, or a rear-wheel drive electric vehicle where only the left and right rear wheels RW_L and RW_R are driven by motors RM_L and RM_R, respectively. That is, the present invention can also be applied to electric vehicles where only the left and right front wheels or only the left and right rear wheels are driven by motors.

[0052] [Control Device]

[0053] The control device 10 is a device (computer) that performs unified control of the entire vehicle V. It can be implemented, for example, through an ECU (Electronic Control Unit) that includes a processor (not shown) for performing various calculations, a memory (not shown) for storing various information, and an interface (not shown) for inputting and outputting data between the control device 10 and the external environment. The control device 10 can be implemented by one ECU or by multiple ECUs.

[0054] In this embodiment, the control device 10 is configured to perform dual-output drive force suppression control by controlling each motor FM_L, FM_R, RM_L, and RM_R respectively.

[0055] Dual-output drive force suppression control is performed, for example, when at least one of the left front wheel FW_L and the right front wheel FW_R slips while the motors FM_L and FM_R are driving the left front wheel FW_L and the right front wheel FW_R, respectively. Furthermore, in dual-output drive force suppression control, for example, the following control is performed: suppressing the drive force of the motor (motor FM_L or motor FM_R) corresponding to the output of the left or right front wheel FW_L or FW_R that has experienced relatively large slippage to suppress the slippage of that output, and suppressing the drive force of the motor corresponding to the output of the left or right front wheel FW_L or FW_R that has experienced relatively small slippage or no slippage to the same value as the drive force of the output of the relatively large slippage.

[0056] Furthermore, the control device 10 can also perform dual-output drive force suppression control when the amount of drive force suppression at the output unit where relatively large slippage occurs in the left and right front wheels FW_L and FW_R is above a predetermined value. For example, suppose the left front wheel FW_L slips while the right front wheel FW_R does not slip. In this case, the main ECU 11 can also perform dual-output drive force suppression control when the difference between the FL base torque and the FL_MTCS base torque (described later) (i.e., the amount of drive force suppression) is above a predetermined value.

[0057] Thus, if dual-output drive force suppression control is performed when the amount of suppression of the drive force of the output unit that causes relatively large slip is above a predetermined value, then when the amount of suppression of the drive force of the output unit that causes relatively large slip is above a predetermined value, the drive force of the output unit that causes relatively small slip or no slip can be suppressed. Therefore, the straight-line stability of the vehicle V can be ensured, and the chance of suppressing the drive force of the output unit that causes relatively small slip or no slip can be reduced.

[0058] Furthermore, the control device 10 can also perform dual-output drive force suppression control when the amount of operation of the accelerator pedal (e.g., the AP opening described later), which serves as the operating element for obtaining braking and driving requests to the vehicle V, is less than a predetermined value. In this way, when the amount of operation of the accelerator pedal of the vehicle V is less than the predetermined value, the drive force of the output section that causes relatively small slippage or no slippage can be suppressed, thus ensuring the straight-line stability of the vehicle V and reducing the chance of suppressing the drive force of the output section that causes relatively small slippage or no slippage.

[0059] Furthermore, the control device 10 can also reduce the amount of driving force suppression of the output unit that experiences relatively small slippage or no slippage when the accelerator pedal operation amount is above a predetermined value, compared to when the accelerator pedal operation amount is below a predetermined value. In this way, by reducing the amount of driving force suppression of the output unit that experiences relatively small slippage or no slippage when the accelerator pedal operation amount is above a predetermined value, compared to when the operation amount is below a predetermined value, the amount of driving force suppression of the output unit that experiences relatively small slippage or no slippage can be suppressed, thereby ensuring the straight-line stability of the vehicle V.

[0060] Alternatively, when the accelerator pedal operation amount is above a predetermined value, the greater the accelerator pedal operation amount, the more the control device 10 reduces the amount of driving force suppression for the output unit that experiences relatively small slippage or no slippage. Thus, when the accelerator pedal operation amount is above a predetermined value, the greater the operation amount, the more the amount of driving force suppression for the output unit that experiences relatively small slippage is reduced, thereby allowing for appropriate control of the amount of driving force suppression for the output unit that experiences relatively small slippage based on the accelerator pedal operation amount.

[0061] The control device 10 will now be described in more detail. However, please note that the example described herein is merely an example and the invention is not limited thereto.

[0062] like Figure 2 As shown, the control device 10 includes, for example, a main ECU 11 and a motor ECU (in... Figure 2 The diagram in the middle is "MOT_ECU")12.

[0063] The main ECU11 and the motor ECU12 work together to control the FM_L, FM_R, RM_L, and RM_R of each motor respectively. Figure 2 The diagram in the middle is labeled "MOT", which implements dual-output drive force suppression control.

[0064] For example, the main ECU 11 calculates the vehicle speed and the slip ratio of each wheel's FW_L, FW_R, RW_L, and RW_R based on the wheel speeds detected by the wheel speed sensors Se1. Furthermore, the main ECU 11 monitors the occurrence of slippage in each wheel's FW_L, FW_R, RW_L, and RW_R based on the slip ratio of each wheel's FW_L, FW_R, RW_L, and RW_R.

[0065] Furthermore, the main ECU 11 derives the base torques FW_L, FW_R, RW_L, and RW_R for each wheel based on the steering angle of the vehicle V detected by the steering angle sensor Se2 and the accelerator pedal opening (AP opening) detected by the AP sensor Se3. Here, the AP opening corresponds to the amount of accelerator pedal operation, which is the operating element for obtaining braking and driving requests to the vehicle V. Additionally, the base torque is the target value of the torque required to output basic driving force from the output unit (i.e., the wheels) when the vehicle V is in motion.

[0066] Hereinafter, the base torque of the left front wheel FW_L will also be referred to as "FL base torque", and the base torque of the right front wheel FW_R will also be referred to as "FR base torque". In addition, the FL base torque and FR base torque will also be collectively referred to as "FL / FR base torque" or "FR / FL base torque".

[0067] In addition, when slippage of each wheel FW_L, FW_R, RW_L, RW_R is detected, the main ECU11 derives the MTCS base torque of each wheel FW_L, FW_R, RW_L, RW_R based on the target rotational speed (in other words, target rotational speed) of each wheel FW_L, FW_R, RW_L, RW_R corresponding to the slip ratio and the base torque of each wheel FW_L, FW_R, RW_L, RW_R.

[0068] Here, the MTCS base torque is the target value of the base torque when the Motor Traction Control System (MTCS) is operating by controlling the output of the motor that drives the corresponding output unit (i.e., the wheel), and it is suppressed compared to the base torque in normal conditions (i.e., when the MTCS is not operating).

[0069] For example, the base torque of the left front wheel FW_L (hereinafter also referred to as "FL_MTCS base torque") is suppressed compared to the normal base torque of the left front wheel FW_L, i.e., the FL base torque. Similarly, the base torque of the right front wheel FW_R (hereinafter also referred to as "FR_MTCS base torque") is suppressed compared to the normal base torque of the right front wheel FW_R, i.e., the FR base torque. Furthermore, FL_MTCS base torque and FR_MTCS base torque will be collectively referred to as "FL / FR_MTCS base torque" or "FR / FL_MTCS base torque" below.

[0070] When the main ECU11 exports the FL / FR_MTCS base torque, it exports the reduction ratio of the left and right front wheels FW_L and FW_R, as well as the difference between the reduction ratios of the left and right front wheels FW_L and FW_R, based on the FL / FR_MTCS base torque and the actual torques of the left and right front wheels FW_L and FW_R received from the motor ECU12 (in other words, the actual MOT torque).

[0071] Hereinafter, the actual torque of the left front wheel FW_L (i.e., the actual torque of the motor FM_L) will be referred to as "FL actual torque", and in particular, the actual torque of FL when MTCS is working will be referred to as "FL_MTCS torque". Furthermore, the indicated torque of the motor FM_L will be referred to as "FL MOT indicated torque".

[0072] Furthermore, the actual torque of the right front wheel FW_R (i.e., the actual torque of the motor FM_R) will be referred to as "FR actual torque" below, and in particular, the actual torque of FR when MTCS is working will be referred to as "FR_MTCS torque". Moreover, the indicated torque of the motor FM_R will be referred to as "FR MOT indicated torque".

[0073] The reduction ratio is an evaluation value that represents the ratio of the actual torque to the indicated torque sent to the corresponding motor. For example, assuming the reduction ratio of the left front wheel FW_L is FL, then FL reduction ratio [%] = FL_MTCS torque / FL MOT indicated torque × 100 [%]. Similarly, assuming the reduction ratio of the right front wheel FW_R is FR, then FR reduction ratio [%] = FR_MTCS torque / FRRMOT indicated torque × 100 [%].

[0074] Furthermore, the main ECU 11 adjusts the FL / FR_MTCS base torque based on the difference in reduction ratios of the left and right front wheels FW_L and FW_R, and the lateral acceleration of the vehicle V (in other words, the vehicle body) detected by the lateral acceleration sensor Se4. The adjusted torque value (the adjusted target MTCS torque described later) is then transmitted to the motor ECU 12 as an indication torque (MOT torque indication). For example, if the FR_MTCS base torque has been adjusted, the main ECU 11 simply transmits the adjusted torque value of the FR_MTCS base torque to the motor ECU 12 as an indication torque for the motor FM_L. Alternatively, when the MTCS is operating and the FL / FR_MTCS base torque does not need adjustment, the main ECU 11 can also transmit the FL / FR_MTCS base torque to the motor ECU 12 as indication torques for the motors FM_L and FM_R, respectively. When the MTCS is not operating, the main ECU 11 simply transmits the FL / FR base torque as an indication torque to the motor ECU 12.

[0075] The same applies to the left and right rear wheels RW_L and RW_R. That is, when the MTCS is working, the main ECU 11 transmits the MTCS base torque of the left and right rear wheels RW_L and RW_R as the indicated torque of the corresponding motor to the motor ECU 12. Similarly, when the MTCS is not working, the main ECU 11 transmits the base torque of the left and right rear wheels RW_L and RW_R as the indicated torque of the corresponding motor to the motor ECU 12. However, in this embodiment, from the viewpoint of ensuring the total driving force of the vehicle V, the MTCS base torque of the left and right rear wheels RW_L and RW_R, which are non-steering wheels, is different from the MTCS base torque of the left and right front wheels FW_L and FW_R, which are steering wheels, and therefore no adjustment based on the aforementioned reduction ratio is performed (for example, refer to...). Figure 7 ).

[0076] The motor ECU12 controls each motor FM_L, FM_R, RM_L, and RM_R based on instructions from the main ECU.

[0077] For example, the motor ECU12 obtains the rotational speed (more specifically, the rotational speed per unit time, i.e., the rotational speed) of each motor FM_L, FM_R, RM_L, and RM_R, and based on this rotational speed, it derives the actual torque of each motor FM_L, FM_R, RM_L, and RM_R (i.e., the actual torque of each wheel FW_L, FW_R, RW_L, and RW_R) and transmits it to the main ECU11.

[0078] Furthermore, the motor ECU 12 controls the FM_L, FM_R, RM_L, and RM_R of each motor based on the indicated torque (MOT torque indication) from the main ECU 11. Specifically, the motor ECU 12 adjusts the indicated torque from the main ECU 11 according to the actual torque, controlling the FM_L, FM_R, RM_L, and RM_R of each motor (adjusted torque indication) separately. For example, if there is a significant deviation between the MOT torque indication from the main ECU 11 and the actual torque, directly outputting torque according to the indicated value would cause an impact on the vehicle V. Therefore, the motor ECU 12 controls the output torque based on the adjusted torque indication, gradually approaching the indicated torque while considering the actual torque.

[0079] [Overview of Dual Output Drive Force Suppression Control]

[0080] Reference Figure 3 The general outline of the control (dual-output drive force suppression control) performed by the control device 10 in this embodiment will be explained. Figure 3In the example shown, the left output section of vehicle V becomes the output section where relatively large slip occurs (hereinafter also referred to as the "Lo_μ wheel"), denoted as "Lo_μ". Therefore, the left front wheel FW_L and the left rear wheel RW_L are both Lo_μ wheels. On the other hand, the right output section of vehicle V becomes the output section where relatively small slip occurs or no slip occurs (hereinafter also referred to as the "Hi_μ wheel"), denoted as "Hi_μ". Therefore, the right front wheel FW_R and the right rear wheel RW_R are both Hi_μ wheels.

[0081] like Figure 3 As shown, for example, when the left front wheel FW_L, which acts as a steering wheel, slips, the control device 10 suppresses the driving force of the motor FM_L (first drive source) that outputs driving force to the slipping left front wheel FW_L (Lo_μ wheel), thereby suppressing slippage in the left front wheel FW_L. Simultaneously, the control device 10 suppresses the driving force DF_FR of the right front wheel FW_R, which is opposite the left front wheel FW_L, to match the driving force DF_FL of the left front wheel FW_L. Furthermore, Figure 3 The driving force DF_FR' indicated by the dashed arrow represents the driving force of the right front wheel FW_R when it is not suppressed.

[0082] On the other hand, even if the left rear wheel RW_L, which is a non-steering wheel, slips, unlike the front wheel side, which is a steering wheel, the control device 10 maintains the driving force DF_RR of the right rear wheel RW_R, which is opposite to the left rear wheel RW_L, at its original value.

[0083] As described above, when the left front wheel FW_L (output of one side) and the right front wheel FW_R (output of the other side) are driven by the motor FM_L (first drive source) and the motor FM_R (second drive source) respectively, at least one of the left front wheel FW_L and the right front wheel FW_R occurs (in Figure 3 In the example shown, when the left front wheel (FW_L) slips, the control device 10 performs dual-output drive force suppression control. In this dual-output drive force suppression control, the drive force (drive torque) of the motor FM_L that outputs drive force to the left front wheel FW_L (Lo_μ wheel) which has a relatively large slippage is suppressed to suppress slippage. At the same time, the drive force (drive torque) of the motor FM_R that outputs drive force to the right front wheel FW_R (Hi_μ wheel) which has not slipped (or has a relatively small slippage) is suppressed to the same value as the drive force DF_FL of the left front wheel FW_L which has a relatively large slippage.

[0084] Therefore, according to the vehicle V equipped with the control device 10, when at least one of the output units (left front wheel FW_L or right front wheel FW_R) is in Figure 3 In the example, when the left front wheel (FW_L) slips (e.g., slip accompanied by acceleration), the output unit that suppresses slippage (in) Figure 3 In the example, the driving force of the left front wheel (FW_L) is used to suppress slippage, and the output of the other party (right front wheel FW_R or left front wheel FW_L) is used to suppress slippage. Figure 3 In the example, the driving force suppression of the right front wheel (FW_R) is related to the output unit where slippage occurs (in Figure 3 In the example, the driving force of the left front wheel (FW_L) is the same value, which can suppress the yaw moment generated by the vehicle V. Therefore, even if the vehicle V does not have a differential device (so-called differential gear), it can suppress the yaw behavior of the vehicle V in the event of slippage of the output part of at least one of the left and right wheels, and ensure the straight-line stability of the vehicle V.

[0085] In addition, Figure 1 and Figure 3 In the example shown, the left and right front wheels FW_L and FW_R of vehicle V become the left and right outputs (i.e., steering wheels) of the side that steers vehicle V, and the left and right rear wheels RW_L and RW_R become the left and right outputs (i.e., non-steering wheels) of the side that does not steer vehicle V. Furthermore, vehicle V has motors RM_L and RM_R as drive sources that output braking force and driving force to the left and right rear wheels RW_L and RW_R, respectively, which do not steer vehicle V. In this case, when at least one of the left and right rear wheels RW_L and RW_R slips while each motor RM_L and RM_R is driving the left and right rear wheels RW_L and RW_R, respectively, the control device 10 suppresses the driving force of the rear wheel with relatively large slippage, thereby suppressing slippage. At the same time, the control device 10 does not suppress the driving force of the rear wheels that do not slip (or have relatively small slippage).

[0086] For example, such as Figure 3 As shown, when the left rear wheel RW_L and the right rear wheel RW_R (other left and right output units) are driven by the motor RM_L (third drive source) and the motor RM_R (fourth drive source) respectively, and at least one of the left and right rear wheels RW_L and RW_R slips, the control device 10 suppresses the driving force (driving torque) of the motor RM_L that outputs driving force to the left rear wheel RW_L (Lo_μ wheel) which has experienced relatively large slippage, in order to suppress slippage. At the same time, the control device 10 does not suppress the driving force (driving torque) of the motor RM_R that outputs driving force to the right rear wheel RW_R (Hi_μ wheel) which has not slipped.

[0087] Therefore, depending on the vehicle V equipped with the control device 10, even if neither of the left or right output units (left rear wheel RW_L or right rear wheel RW_R) is steered, in Figure 3In the example, the left rear wheel (RW_L) slips. Furthermore, even in a structure where the left and right output units (left rear wheel RW_L and right rear wheel RW_R) are driven by motor RM_L (the third drive source) and motor RM_R (the fourth drive source) respectively, without steering the vehicle V, the other output unit (right rear wheel RW_R or left rear wheel RW_L) is not suppressed. Figure 3 In the example, the driving force of the right rear wheel (RW_R) is used to suppress the total driving force in vehicle V and ensure the straight-line stability of vehicle V.

[0088] exist Figure 4 , Figure 5 as well as Figure 7 The flowchart shows an example of the control flow of the dual-output drive force suppression control implemented by the control device 10.

[0089] Figure 4 The control shown in the flowchart is executed, for example, when slippage of the left and right front wheels FW_L and FW_R, which are steering wheels, is detected. Specifically, when slippage of at least one of the left front wheel FW_L and the right front wheel FW_R is detected, the control device 10 executes control on the left front wheel FW_L and the right front wheel FW_R respectively. Figure 4 The control is shown in the flowchart.

[0090] exist Figure 4 In the flowchart, the control device 10 derives the MTCS base torque through the processing in step S1 (FL_MTCS base torque if it is processing about the left front wheel FW_L, and FR_MTCS base torque if it is processing about the right front wheel FW_R).

[0091] Next, the control device 10, through the processing in step S2, derives the reduction ratios FW_L and FW_R for the left and right front wheels. Since the reduction ratios have already been described above, their explanation is omitted here.

[0092] Next, the control device 10 performs Hi_μ wheel determination processing through step S3. In this Hi_μ wheel determination processing, the control device 10 determines whether the wheel among the left and right front wheels FW_L and FW_R, which is the object of the current routine, is a wheel that has not slipped or has slipped relatively little (i.e., the Hi_μ wheel). The specific processing sequence of this Hi_μ wheel determination processing is treated as a subroutine. Figure 5 The flowchart is shown.

[0093] exist Figure 5In the flowchart, the control device 10 calculates the difference between the reduction ratios of the left and right front wheels FW_L and FW_R through the processing in step S11. That is, in the processing of step S11, the difference between the left and right front wheels FW_L and FW_R is calculated based on the reduction ratios of the left and right front wheels FW_L and FW_R derived through the processing in step S2 above.

[0094] Next, the control device 10 determines, through the processing in step S12, whether the difference in the reduction ratio calculated in step S11 is greater than a predetermined threshold ThR. The threshold ThR is preset as a threshold used to determine whether the wheel being targeted in the current routine is a Hi_μ wheel or a Lo_μ wheel.

[0095] Furthermore, if the difference in reduction ratios calculated in step S11 is below the threshold ThR, and therefore is determined as "no" in step S12, the control device 10 proceeds to step S13, determining that the wheel targeted in the current routine is the Lo_μ wheel. Afterward, the control device 10 terminates. Figure 5 The subroutine shown in the flowchart enters the above... Figure 4 The processing of step S4 in the flowchart.

[0096] In contrast, if the difference in deceleration ratios calculated in step S11 is greater than the threshold ThR, and thus is determined to be "yes" in step S12, the control device 10 proceeds to step S14 to determine whether the lateral acceleration of the vehicle V is greater than a predetermined threshold ThG. The threshold ThG is preset as a threshold specifically used to determine the behavior of the vehicle V while it is turning.

[0097] Furthermore, if the lateral acceleration of vehicle V is greater than the predetermined threshold ThG and is thus determined to be "yes" in the processing of step S14, the control device 10 enters the processing of step S13 described above.

[0098] For example, when cornering, if the lateral acceleration of vehicle V exceeds a threshold ThG, active yaw control can be activated separately to limit the driving force of vehicle V.

[0099] Therefore, in this embodiment, when the lateral acceleration of the vehicle V is greater than the threshold ThG, the control device 10 sets any wheel as the Lo_μ wheel, thereby not implementing dual-output drive force suppression control that suppresses the driving force of the Hi_μ wheel to the same value as the driving force of the Lo_μ wheel.

[0100] In other words, in this embodiment, when the lateral acceleration of the vehicle V is less than the threshold ThG (i.e., a predetermined value), the control device 10 suppresses the driving force of the output unit that has relatively small slippage or no slippage in the dual-output driving force suppression control. Therefore, when the lateral acceleration of the vehicle V is less than the threshold ThG, the driving force of the output unit that has relatively small slippage or no slippage can be suppressed, thus ensuring the straight-line stability of the vehicle V and reducing the chance of suppressing the driving force of the output unit that has relatively small slippage or no slippage.

[0101] However, step S14 is not necessary and can be omitted.

[0102] On the other hand, if the lateral acceleration of vehicle V is below a predetermined threshold ThG, and therefore is determined to be "no" in step S14, the control device 10 proceeds to step S15, determining that the wheel being processed in the current routine is the Hi_μ wheel. Afterward, the control device 10 terminates. Figure 5 The subroutine shown in the flowchart enters the above... Figure 4 The processing of step S4 in the flowchart.

[0103] return Figure 4 The flowchart will be further explained below. Control device 10 is in... Figure 4 In step S4, based on the result of the Hi_μ wheel determination process in step S3, it is determined whether the wheel being considered in the current routine is a Hi_μ wheel. If the wheel being considered is not a Hi_μ wheel, i.e., is a Lo_μ wheel, and is therefore determined to be "no" in step S4, the control device 10 proceeds to step S5.

[0104] In step S5, the control device 10 uses the indicated torque (in other words, the torque indication value) of the motor corresponding to the target wheel as the MTCS base torque to control the motor. Thus, as described above... Figure 3 As shown, for example, when the left front wheel FW_L, which is the steering wheel, slips, the control device 10 can control the motor FM_L, which outputs driving force to the left front wheel FW_L (Lo_μ wheel), based on the MTCS base torque (FL_MTCS base torque). In this way, by controlling the motor FM_L using the torque indication value as the MTCS base torque, the driving torque output by the motor FM_L can be suppressed, thereby suppressing slippage at the left front wheel FW_L. When the driving force control of the Lo_μ wheel is implemented through the process in step S5, the control device 10 ends. Figure 4 The control flow is shown.

[0105] For example, in Figure 6The timing diagram shows an example of the behavior of the motor FM_L torque indication value (MOT torque indication) and the drive torque (actual torque) output by the motor FM_L when the left front wheel FW_L is a Lo_μ wheel and the above-mentioned step S5 has been implemented.

[0106] like Figure 6 As shown in the timing diagram of the <Lo_μ wheel>, when the control device 10 detects slippage of the left front wheel FW_L at time t1, it gradually reduces the torque indication value of the motor FM_L towards the MTCS base torque (FL_MTCS base torque). As a result, the actual torque of the motor FM_L decreases, and the slippage of the left front wheel FW_L is suppressed.

[0107] return Figure 4 The flowchart will be further explained below. Control device 10 is in... Figure 4 In the process of step S4 shown, if the wheel that is the object in the current routine is Hi_μ wheel and is thus determined to be "yes", then proceed to the process of step S6.

[0108] Furthermore, in step S6, it is determined whether the accelerator pedal opening (AP opening) is greater than a predetermined threshold ThA. The threshold ThA is preset as a threshold for determining the driver's acceleration intention. For example, if the AP opening is greater than the threshold ThA, the control device 10 determines that the driver still has the intention to accelerate despite being aware of slippage, and implements drive force control corresponding to the size of the AP opening. Therefore, if the AP opening is below the threshold ThA and is thus determined to be "no" in step S6, the process proceeds to step S5, where, as before, the indicated torque (in other words, the torque indication value) of the motor corresponding to the target wheel is used as the MTCS base torque to control the motor.

[0109] In contrast, if the AP opening degree is greater than the threshold ThA and thus is determined to be "yes" in step S6, the control device 10 proceeds to the processing in step S7.

[0110] In step S7, the motor is controlled by using the value obtained by adjusting the base torque of the MTCS of the wheel that is the object in the current routine (hereinafter also referred to as the "adjusted target MTCS torque") as the indicated torque (in other words, the torque indication value) of the motor corresponding to that wheel.

[0111] The adjusted target MTCS torque is, for example, the base MTCS torque plus or minus a specified value corresponding to the AP opening size. For example, as described above. Figure 3As shown, when the left front wheel FW_L, which acts as the steering wheel, slips, the control device 10 controls the motor FM_R, which outputs driving force to the right front wheel FW_R (Hi_μ wheel) opposite the slipping left front wheel FW_L, based on the adjusted target MTCS torque. By using the torque indication value of the motor FM_R as the adjusted target MTCS torque to control the motor FM_R, the motor FM_R outputs a driving torque corresponding to the AP opening degree. When the driving force control of the Hi_μ wheel is implemented through the process in step S7, the control device 10 terminates. Figure 4 The control flow is shown.

[0112] For example, in Figure 6 The timing diagram shows an example of the behavior of the torque indication value (MOT torque indication) of the motor FM_R and the drive torque (actual torque) output by the motor FM_R when the right front wheel FW_R is a Hi_μ wheel and the above-mentioned step S7 has been implemented.

[0113] like Figure 6 As shown in the timing diagram of <Hi_μ wheel>, when control device 10 detects slippage of the left front wheel FW_L at time t1, it gradually reduces the torque indication value (MOT torque indication) of motor FM_R towards the torque indication value (FL_MTCS base torque) of motor FM_L of the slipping left front wheel FW_L. Consequently, the actual torque of motor FM_R also decreases along with the actual torque of motor FM_L. As a result, slippage occurring at the left front wheel FW_L is suppressed, and the driving force of the left front wheel FW_L and right front wheel FW_R, which act as steering wheels, is also suppressed, thus ensuring the straight-line stability of vehicle V.

[0114] Furthermore, in the above-mentioned step S7, the control device 10 controls the motor (e.g., motor FM_R) corresponding to the Hi_μ wheel by outputting a drive torque corresponding to the opening size of AP.

[0115] Therefore, as Figure 6 As shown in the <Hi_μ wheel> in the timing diagram, after time t2, when the accelerator pedal (operating element) operation amount, i.e., AP opening degree, is greater than the threshold ThA, the control device 10 reduces the suppression amount of the actual torque of the motor FM_R compared to the case where the AP opening degree is less than the threshold ThA. That is, it reduces the suppression amount of the driving force of the right front wheel FW_R that outputs the driving torque of the motor FM_R.

[0116] like Figure 6As shown in the timing diagram of <Hi_μ wheel>, for example, the larger the AP opening degree, the more the control device 10 reduces the amount of suppression of the driving force of the right front wheel FW_R that has not slipped. Therefore, it is possible to suppress the amount of suppression of the driving force of the output unit that has not slipped, namely the right front wheel FW_R, and ensure the straight-line stability of the vehicle V. In addition, it is possible to appropriately control the amount of suppression of the driving force of the output unit that has not slipped, namely the right front wheel FW_R, according to the AP opening degree (the amount of operation of the operating member).

[0117] Figure 7 The control shown in the flowchart is executed, for example, when slippage of the left and right rear wheels RW_L and RW_R, which are non-steering wheels, is detected. Specifically, the control device 10 executes the control on the rear wheel that has slipped among the left and right rear wheels RW_L and RW_R. Figure 7 The control is shown in the flowchart.

[0118] exist Figure 7 In the flowchart, the control device 10 derives the MTCS base torque through the processing in step S21. For example, if the wheel being processed in the current routine is the left rear wheel RW_L, then the MTCS base torque for the left rear wheel RW_L (i.e., the motor RM_L) is derived through the processing in step S21. Similarly, if the wheel being processed in the current routine is the right rear wheel RW_R, then the MTCS base torque for the right rear wheel RW_R (i.e., the motor RM_R) is derived through the processing in step S21.

[0119] Next, the control device 10, through the processing in step S22, uses the torque indication value of the motor corresponding to the wheel that is the object in the current routine as the MTCS base torque derived in the processing in step S21 to control the motor RM_L or the motor RM_R. When the drive force control of the Lo_μ wheel is implemented through the processing in step S22, the control device 10 ends. Figure 7 The control flow is shown.

[0120] For example, as mentioned above Figure 3 As shown, when the left rear wheel RW_L (which is not a steering wheel) slips, the control device 10 controls the motor RM_L, which outputs driving force to the left rear wheel RW_L (Lo_μ wheel), based on the MTCS base torque. By controlling the motor RM_L using the torque indication value as the MTCS base torque, the driving torque output by the motor RM_L is suppressed, thereby suppressing slippage occurring on the left rear wheel RW_L.

[0121] On the other hand, as mentioned above Figure 3 As shown, for the right rear wheel RW_R, which is not a steering wheel and has not slipped, the above procedure is not performed. Figure 7The control is illustrated in the flowchart. Therefore, for example, when the left rear wheel RW_L (which is not a steering wheel) slips, the control device 10 suppresses the driving force (driving torque) of the motor RM_L that outputs driving force to the slipping left rear wheel RW_L (Lo_μ wheel) to suppress slippage. Simultaneously, the control device 10 does not suppress the driving force (driving torque) of the motor RM_R that outputs driving force to the non-slipping right rear wheel RW_R (Hi_μ wheel). That is, when the left rear wheel RW_L (which is not a steering wheel) slips, the control device 10 suppresses the driving force of the slipping left rear wheel RW_L to suppress slippage. At the same time, the control device 10 does not suppress the driving force of the non-slipping right rear wheel RW_R.

[0122] Therefore, even if the left rear wheel RW_L (or right rear wheel RW_R) slips without steering the vehicle V, the driving force of the right rear wheel RW_R (or left rear wheel RW_L) that has not slipped is not suppressed, thereby suppressing the total driving force in the vehicle V and ensuring the straight-line stability of the vehicle V.

[0123] The embodiments of the present invention have been described above, but the present invention is not limited to this example. Obviously, those skilled in the art can conceive of various modifications or alterations within the scope of the technical solutions described, and it should be understood that these modifications and alterations also fall within the technical scope of the present invention.

[0124] For example, in the above embodiments, an example of setting the vehicle V in the present invention as an electric vehicle driven by an electric motor has been described, but it is not limited thereto. For example, the vehicle V in the present invention may also be a hybrid electric vehicle equipped with both an electric motor and an internal combustion engine as drive sources.

[0125] Furthermore, without departing from the spirit of the invention, the constituent elements in the above embodiments can be combined in any way.

[0126] The following are at least described in this specification and other documents. Furthermore, although the corresponding components in the above embodiments are shown in parentheses, the present invention is not limited thereto.

[0127] (1) A mobile body (vehicle V), wherein,

[0128] The mobile body has:

[0129] The first drive source (motor FM_L) outputs braking force and driving force to either the left or right output unit (left front wheel FW_L);

[0130] The second drive source (motor FM_R) outputs braking and driving forces to the output units on the left and right sides (right front wheel FW_R); and

[0131] Control device (10), which controls the first drive source and the second drive source,

[0132] When at least one of the outputs of one party and the other party slips while the first drive source and the second drive source are respectively driving the output of the other party, the control device performs dual output drive force suppression control.

[0133] In the dual-output driving force suppression control, the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively large slippage is suppressed to suppress the slippage, and the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively small slippage or no slippage is suppressed to the same value as the driving force of the output unit that experiences relatively large slippage.

[0134] According to (1), when slippage occurs in at least one of the output units (e.g., slippage accompanied by acceleration), the driving force of the slipping output unit is suppressed to inhibit slippage, and the driving force of the other output unit is suppressed to the same value as the driving force of the slipping output unit, thereby suppressing the yaw moment of the moving body. Thus, even if the moving body does not have a differential device (so-called differential gear), the deflection behavior of the moving body in the event of slippage in at least one of the output units can be suppressed, ensuring the straight-line stability of the moving body.

[0135] (2) The movable body according to (1), wherein,

[0136] The control device performs the dual-output drive force suppression control when the amount of suppression of the driving force of the output section that experiences relatively large slippage is above a predetermined value.

[0137] According to (2), when the amount of suppression of the driving force of the output section that causes relatively large slippage is above a specified value, the driving force of the output section that causes relatively small slippage or no slippage can be suppressed, thus ensuring the straight-line stability of the moving body and reducing the chance of suppressing the driving force of the output section that causes relatively small slippage or no slippage.

[0138] (3) The movable body according to (2), wherein,

[0139] The moving body includes a lateral acceleration acquisition unit (lateral acceleration sensor Se4) for acquiring the lateral acceleration of the moving body.

[0140] When the lateral acceleration is less than a specified value, the control device suppresses the driving force of the output unit that has experienced relatively small slippage or no slippage in the dual output unit driving force suppression control.

[0141] According to (3), when the lateral acceleration is less than a specified value, the driving force of the output part that has relatively small slippage or no slippage can be suppressed, thus ensuring the straight-line stability of the moving body and reducing the chance of suppressing the driving force of the output part that has relatively small slippage or no slippage.

[0142] (4) The movable body according to (1), wherein,

[0143] The mobile body has an operating element (AP sensor Se3) for acquiring braking and driving requests for the mobile body.

[0144] When the amount of operation of the operating element is less than a specified value, the control device performs the dual-output drive force suppression control.

[0145] According to (4), the driving force of the output unit that has relatively small slippage or no slippage can be suppressed when the operation amount of the operating member that obtains the braking request and driving request is less than a specified value. Therefore, the straight-line stability of the moving body can be ensured, and the chance of suppressing the driving force of the output unit that has relatively small slippage or no slippage can be reduced.

[0146] (5) The movable body according to (4), wherein,

[0147] When the operation amount of the operating member is above the predetermined value, the control device reduces the amount of suppression of the driving force of the output unit that has experienced relatively small slippage or no slippage, compared to when the operation amount of the operating member is less than the predetermined value.

[0148] According to (5), when the operation amount of the operating member is above a specified value, compared with the case where the operation amount is less than the specified value, the amount of suppression of the driving force of the output unit that has relatively small slippage or no slippage is reduced, thereby suppressing the amount of suppression of the driving force of the output unit that has relatively small slippage or no slippage and ensuring the straight-line stability of the moving body.

[0149] (6) The movable body according to (5), wherein,

[0150] When the operating amount of the operating member is above a predetermined value, the greater the operating amount of the operating member, the more the control device reduces the amount of suppression of the driving force of the output unit that has experienced relatively small slippage or no slippage.

[0151] According to (6), when the operating amount of the operating member is above a specified value, the larger the operating amount, the smaller the amount of suppression of the driving force of the output unit that causes relatively small slippage. Thus, the amount of suppression of the driving force of the output unit that causes relatively small slippage can be appropriately controlled according to the operating amount of the operating member.

[0152] (7) The movable body according to (1), wherein,

[0153] The output unit on either the left or right side (left front wheel FW_L) and the output unit on the other side (right front wheel FW_R) are the output units for steering the moving body.

[0154] The mobile body has other left and right outputs that do not steer the mobile body, and a drive source (motor RM_L, RM_R) that outputs braking force and driving force to the other left and right outputs.

[0155] When at least one of the other left and right outputs slips while the drive source is driving the other left and right outputs, the control device suppresses the driving force of the other left and right outputs that have slipped relatively large in order to suppress the slip, and does not suppress the driving force of the other left and right outputs that have slipped relatively small or have not slipped.

[0156] According to (7), even if either of the left or right output sections that does not steer the moving body slips, the driving force of the other output section is not suppressed, thereby suppressing the total driving force in the moving body and ensuring the straight-line stability of the moving body.

[0157] (8) The movable body according to (7), wherein,

[0158] The drive source that outputs braking force and driving force to the other left and right output units includes:

[0159] The third drive source (motor RM_L) outputs braking force and driving force to either of the other left and right output units; and

[0160] The fourth drive source (motor RM_R) outputs braking and driving forces to the other of the other left and right output units.

[0161] When at least one of the other left and right outputs slips while the third and fourth drive sources are driving the other left and right outputs, the control device suppresses the driving force of the other left and right outputs that have slipped relatively large in order to suppress the slip, and does not suppress the driving force of the other left and right outputs that have slipped relatively small or have not slipped.

[0162] According to (8), even if the left and right output parts that do not steer the moving body are driven by the third drive source and the fourth drive source respectively, the suppression amount of the total driving force in the moving body can be suppressed, and the straight-line stability of the moving body can be ensured.

Claims

1. A mobile body, wherein, The mobile body has: The first drive source outputs braking force and driving force to either the left or right output section; The second drive source outputs braking and driving forces to the output units on the left and right sides; and A control device that controls the first drive source and the second drive source. When at least one of the outputs of one party and the other party slips while the first drive source and the second drive source are respectively driving the output of the other party, the control device performs dual output drive force suppression control. In the dual-output driving force suppression control, the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively large slippage is suppressed to suppress the slippage, and the driving force of the first driving source or the second driving source that outputs driving force to the output unit that experiences relatively small slippage or no slippage is suppressed to the same value as the driving force of the output unit that experiences relatively large slippage.

2. The mobile body according to claim 1, wherein, The control device performs the dual-output drive force suppression control when the amount of suppression of the driving force of the output section that experiences relatively large slippage is above a predetermined value.

3. The mobile body according to claim 2, wherein, The moving body includes a lateral acceleration acquisition unit for acquiring the lateral acceleration of the moving body. When the lateral acceleration is less than a specified value, the control device suppresses the driving force of the output unit that has experienced relatively small slippage or no slippage in the dual output unit driving force suppression control.

4. The mobile body according to claim 1, wherein, The mobile body includes operating components for acquiring braking and driving requests for the mobile body. When the amount of operation of the operating element is less than a specified value, the control device performs the dual-output drive force suppression control.

5. The mobile body according to claim 4, wherein, When the operation amount of the operating member is above the predetermined value, the control device reduces the amount of suppression of the driving force of the output unit that has experienced relatively small slippage or no slippage, compared to when the operation amount of the operating member is less than the predetermined value.

6. The mobile body according to claim 5, wherein, When the operating amount of the operating member is above a predetermined value, the greater the operating amount of the operating member, the more the control device reduces the amount of suppression of the driving force of the output unit that has experienced relatively small slippage or no slippage.

7. The mobile body according to claim 1, wherein, The output unit on either the left or right side and the output unit on the other side are output units for steering the moving body. The mobile body includes other left and right output units that do not steer the mobile body, and a drive source that outputs braking force and driving force to the other left and right output units. When at least one of the other left and right outputs slips while the drive source is driving the other left and right outputs, the control device suppresses the driving force of the other left and right outputs that have slipped relatively large in order to suppress the slip, and does not suppress the driving force of the other left and right outputs that have slipped relatively small or have not slipped.

8. The mobile body according to claim 7, wherein, The drive source that outputs braking force and driving force to the other left and right output units includes: A third drive source outputs braking force and driving force to either of the other left and right output units; and The fourth drive source outputs braking and driving forces to the other of the other left and right output units. When at least one of the other left and right outputs slips while the third and fourth drive sources are driving the other left and right outputs, the control device suppresses the driving force of the other left and right outputs that have slipped relatively large in order to suppress the slip, and does not suppress the driving force of the other left and right outputs that have slipped relatively small or have not slipped.

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