Vehicle behavior control system

Abstract

To provide a vehicle behavior control system that is more responsive and has no trade-offs compared to conventional vehicle behavior control systems. [Solution] A vehicle behavior control device for controlling the behavior of a vehicle comprises: an acquisition unit for acquiring vehicle speed; and a calculation unit that uses different gain information according to the acquired vehicle speed to calculate the braking and driving torque values ​​of the front wheels and the rear wheels of the vehicle, and outputs the braking and driving torque values ​​of the front wheels and the rear wheels to a control unit that controls the driving of the front wheels and the driving of the rear wheels.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a vehicle behavior control device. [Background technology]

[0002] In recent years, vibration damping technologies have been proposed to reduce the swaying of the vehicle body caused by road surface irregularities and other factors. For example, there is a technology that calculates a target motion state to control the behavior of the vehicle body and controls the behavior of the vehicle body with driving force or braking force based on this. Another technology uses devices with variable spring constants in the front and rear suspensions to control the vibration phase of the front and rear suspensions so that they are in phase, thereby controlling the behavior of the vehicle body. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5862273 [Patent Document 2] Patent No. 3052687 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, conventional vehicle behavior control systems have room for improvement in areas that are often conflicting, such as responsiveness and unintended changes in vehicle height.

[0005] Therefore, one of the objectives of the present invention is to provide a vehicle behavior control device that is more responsive and has no trade-offs compared to conventional vehicle behavior control devices. [Means for solving the problem]

[0006] A vehicle behavior control device according to an embodiment is, as an example, a vehicle behavior control device that controls the behavior of a vehicle by generating an arbitrary vertical force via a suspension mechanism by outputting driving force or braking force to the front wheels and rear wheels, and comprises: an acquisition unit that acquires the vehicle speed; and a calculation unit that uses different gain information according to the acquired vehicle speed to calculate the braking and driving torque values ​​of the front wheels and the rear wheels of the vehicle, and outputs the braking and driving torque values ​​of the front wheels and the rear wheels to a control unit that controls the driving of the front wheels and the driving of the rear wheels. [Effects of the Invention]

[0007] According to the embodiment of the vehicle behavior control device, there is no need for air springs or units that control the amount of air in the air springs according to the vehicle speed, and pitch vibration and heave vibration of the vehicle can be efficiently reduced by the driving force of the vehicle. As a result, a vehicle behavior control device with higher responsiveness and no trade-offs compared to conventional devices can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram showing an example of the configuration of a vehicle behavior control device according to the first embodiment. [Figure 2] Figure 2 shows an example of the installation state of the in-vehicle sensor, suspension mechanism, and SC-ECU according to the first embodiment. [Figure 3] Figure 3 is a block diagram showing an example of the functional configuration of a vehicle behavior control device according to the first embodiment. [Figure 4] Figure 4 is a diagram illustrating an example of the control flow performed by the vehicle behavior control device according to the first embodiment. [Figure 5] Figure 5 illustrates a vehicle that, while traveling on a road surface, drives over a protrusion on the road surface by having the front wheels drive onto it first, then the rear wheels, in that order. [Figure 6A] Figure 6A is a graph showing the temporal changes in stroke amount, pitch angle, and heave amount when the vehicle speed is within the target speed range. [Figure 6B]FIG. 6B is a graph showing the temporal changes in the stroke amount, pitch angle, and heave amount when the vehicle speed is not within the target speed range. [Figure 7] FIG. 7 is a table summarizing whether the pitch behavior and heave behavior of the vehicle increase or decrease respectively when the vehicle speed is within or not within the target speed range in the case where the resonance frequency Fr of the front wheels < the resonance frequency Rr of the rear wheels. [Figure 8] FIG. 8 is a diagram for explaining the vehicle behavior control realized by the vehicle behavior control device when the vehicle speed is not within the target speed range. [Figure 9] FIG. 9 is a diagram for explaining an example of the control flow implemented by the vehicle behavior control device according to the second embodiment. [Figure 10] FIG. 10 is a diagram showing an example of the pitch rate waveform of the vehicle when the vehicle has made the crossing shown in FIG. 5.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, exemplary embodiments of the present invention will be disclosed. The configurations of the embodiments shown below, as well as the actions, results, and effects brought about by such configurations, are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments, and it is possible to obtain at least one of various effects and derivative effects based on the basic configuration.

[0010] (First Embodiment) FIG. 1 is a block diagram showing an example of the configuration of a vehicle 1 equipped with a vehicle behavior control device 2 according to the first embodiment.

[0011] The vehicle 1 is a vehicle such as a hybrid vehicle or a four-wheel drive vehicle that can control the driving and braking (regeneration) of the front and rear wheels.

[0012] Vehicle 1 includes an MC (Main Control)-ECU (Electronic Control Unit) 10, an SC (Suspension Control)-ECU 11 (an example of an electronic control unit), a communication I / F (Interface) 12, a user I / F 13, an on-board sensor 14, a drive mechanism 21, a braking mechanism 22, a steering mechanism 23, a suspension mechanism 24, etc. These components 10-14 and 21-24 are connected to each other via a CAN (Controller Area Network) 20 so that they can communicate with one another.

[0013] The MC-ECU10 is a unit that performs overall control of vehicle 1 based on various data acquired via CAN20. The MC-ECU10 may be configured using a microprocessor including a CPU (Central Processing Unit) that performs calculations according to a program, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), etc.

[0014] The MC-ECU10 calculates parameters related to the heave of the vehicle 1 and at least one parameter related to the pitch of the vehicle 1 based on the detected values ​​output from at least three acceleration sensors, which will be described later. For example, the MC-ECU10 defines a plane from the positions of at least three acceleration sensors, analyzes the temporal change of that plane based on the detected values ​​output from the acceleration sensors, and calculates parameters related to the heave of the vehicle 1 and at least one parameter related to the pitch of the vehicle 1.

[0015] Here, the parameter relating to the heave of vehicle 1 is, for example, the heave speed (vertical speed) of vehicle 1. Also, at least one parameter relating to the pitch of vehicle 1 is, for example, the pitch rate and pitch angle of vehicle 1. In the following explanation, for the sake of specificity, we will take the example where the parameter relating to the heave of vehicle 1 is the heave speed of vehicle 1, and at least one parameter relating to the pitch of vehicle 1 is the pitch rate and pitch angle of vehicle 1. However, we are not limited to this example, and for example, at least one parameter relating to the pitch of vehicle 1 may be only the pitch rate of vehicle 1, or only the pitch angle of vehicle 1. Furthermore, at least one parameter relating to the pitch of vehicle 1 may include pitch parameters other than the pitch rate and pitch angle of vehicle 1.

[0016] Furthermore, the MC-ECU10 controls the drive mechanism 21 and the braking mechanism 22 based on the control information output from the vehicle behavior control device 2. Note that the MC-ECU10 is an example of a control unit.

[0017] The SC-ECU11 is a unit that performs processing to control the suspension mechanism 24 based on various data acquired via CAN20. In addition to processing to control the suspension mechanism 24, the SC-ECU11 in this embodiment also performs processing related to the generation of vehicle information. The SC-ECU11 may be configured using a microprocessor including a CPU that performs arithmetic processing according to a program, an FPGA, an ASIC, etc.

[0018] Furthermore, the SC-ECU11 includes a vehicle behavior control device 2. The vehicle behavior control device 2 uses different gain information depending on the vehicle speed (vehicle speed in the longitudinal direction) obtained from the MC-ECU10 to calculate the braking and driving torque values ​​of the front wheels of the vehicle 1 and the braking and driving torque values ​​of the rear wheels of the vehicle 1. Here, the gain information refers to a gain value as a constant predetermined according to the vehicle speed, a function that determines the gain value from the vehicle speed, a map, table, or calculation formula that determines the gain value from the vehicle speed, etc. In this embodiment, for the sake of concrete explanation, we will take the example that the gain information is a gain value as a constant predetermined according to the vehicle speed.

[0019] Specifically, if the acquired vehicle speed is within the target speed range (described later), the vehicle behavior control device 2 calculates the braking and driving torque values ​​for the front wheels and the rear wheels using the first gain information, the vehicle speed, and the heave speed of vehicle 1. If the acquired vehicle speed is outside the target range, the vehicle behavior control device 2 calculates the braking and driving torque values ​​for the front wheels and the rear wheels using second gain information (different from the first gain information), the vehicle speed, the pitch rate, and the pitch angle. The configuration and functions of the vehicle behavior control device 2 will be explained in detail later.

[0020] The communication interface 12 is a unit that establishes communication with external devices such as the server 3 via the communication network 5 in accordance with a predetermined communication protocol. The user interface 13 is a unit that sends and receives information between the vehicle 1 and the user (occupant of the vehicle 1, etc.), and may be, for example, a display, speaker, microphone, operation unit, touch panel, etc. installed inside the vehicle. The on-board sensor 14 is a sensor mounted on the vehicle 1, and includes an acceleration (gravity) sensor, vehicle height sensor, wheel speed sensor, distance measuring sensor, etc.

[0021] The drive mechanism 21 is a mechanism that generates propulsion for the vehicle 1, and is configured using, for example, an engine, motor, throttle mechanism, etc.

[0022] The braking mechanism 22 is a mechanism that generates braking force for the vehicle 1, and is configured using, for example, brake discs, brake pads, a hydraulic mechanism, a regenerative braking mechanism, etc.

[0023] The steering mechanism 23 is a mechanism that changes the direction of travel of the vehicle 1, and is configured using, for example, a steering wheel, a linkage mechanism, a power steering mechanism, etc.

[0024] The suspension mechanism 24 connects the vehicle body and the wheel axle of the vehicle 1 and provides a cushioning effect to soften shocks from the road surface. It is composed of shock absorbers (dampers), springs, actuators, etc. The suspension mechanism 24 in this embodiment is an electronically controlled mechanism that can adjust damping force, vehicle height, etc., in accordance with control signals from the SC-ECU 11.

[0025] Note that the configuration of vehicle 1 is not limited to the above. For example, other ECUs besides MC-ECU10 and SC-ECU11 may be connected to CAN20.

[0026] Figure 2 shows an example of the installation state of the on-board sensors 14 (14A to 14D), suspension mechanism 24, and SC-ECU 11 of the first embodiment. The on-board sensors 14 of this embodiment include acceleration sensors 14A and 14B, vehicle height sensor 14C, and wheel speed sensor 14D. Note that the group of sensors including these acceleration sensors 14A and 14B, vehicle height sensor 14C, and wheel speed sensor 14C may be collectively referred to as the on-board sensors 14.

[0027] The acceleration sensor 14A is located on the front side of the vehicle body 51, and the acceleration sensor 14B is located on the rear side of the vehicle body 51. The acceleration sensor 14B may be built into the SC-ECU 11. Based on the detection signals from the acceleration sensors 14A and 14B, the acceleration acting on the vehicle 1 (vehicle body 51) in all directions can be measured.

[0028] The vehicle height sensor 14C is a sensor that detects the stroke displacement of each wheel. Based on the detection results from each vehicle height sensor 14C, the difference in vehicle height values ​​of each wheel (for example, the difference in vehicle height values ​​of a pair of wheels located diagonally opposite each other) can be measured, and based on this difference in vehicle height values, the amount of warp related to the twist of the vehicle body 51 can be measured.

[0029] The wheel speed sensor 14D is a sensor that detects the rotational speed of each wheel. Based on the detection results from each wheel speed sensor 14D, the difference in rotational speed of each wheel (for example, the difference in rotational speed of a pair of wheels located diagonally opposite each other) can be measured, and the amount of warp can be measured based on this difference in rotational speed.

[0030] The configuration of the in-vehicle sensor 14 is not limited to the above. For example, the number and installation location of acceleration sensors 14A and 14B should be determined appropriately according to the shape of the vehicle 1, etc.

[0031] Figure 3 is a block diagram showing an example of the functional configuration of the vehicle behavior control device 2 of the first embodiment. The vehicle behavior control device 2 includes an acquisition unit 200 and a calculation unit 204. These functional components, the acquisition unit 200 and the calculation unit 204, can be configured, for example, through the cooperation of hardware elements such as a CPU, memory, and logic circuits built into the SC-ECU 11 and a program (software element) that controls the CPU.

[0032] The acquisition unit 200 acquires the vehicle speed, heave speed, pitch rate, and pitch angle of vehicle 1 transmitted from the MC-ECU 10. The acquisition unit 200 outputs the acquired vehicle speed, etc., to the calculation unit 204.

[0033] The calculation unit 204 calculates the drive or braking torque value in order to effectively suppress vehicle vibration by using gain information related to heave and gain information related to pitch according to the vehicle speed. The calculation unit 204 determines whether the vehicle speed acquired from the acquisition unit 200 is within the target range. Here, the target range refers to the range of speeds that are used as a reference when determining the sprung mass resonance frequency of the front wheels and the sprung mass resonance frequency of the rear wheels in the design of sprung mass vibration control for vehicle 1. The target range is also called the target speed range, and the vehicle speed included in the target speed range is also called the target vehicle speed.

[0034] The calculation unit 204 switches the gain information according to the acquired vehicle speed and calculates the braking torque value related to the driving or braking of the front wheels of the vehicle 1 and the braking torque value related to the driving or braking of the rear wheels of the vehicle 1.

[0035] Specifically, if the calculation unit 204 determines that the acquired vehicle speed is within the target range, it uses the vehicle speed, heave speed, and first gain information to calculate the braking and driving torque values ​​for the front wheels and the rear wheels. Here, the first gain information is a gain value (first gain value / gain information related to heave) set to prioritize the reduction of heave vibration of vehicle 1. If the calculation unit 204 determines that the acquired vehicle speed is not within the target range, it uses the vehicle speed, pitch rate, pitch angle, and second gain information to calculate the braking and driving torque values ​​for the front wheels and the rear wheels. Here, the second gain information is a gain value (second gain value / gain information related to pitch) set to prioritize the reduction of pitch vibration of vehicle 1. The second gain information can be pre-set as individual values, for example, as the second gain value for a gain that takes vehicle speed and pitch rate as inputs, and as the second gain value for a gain that takes vehicle speed and pitch angle as inputs.

[0036] The calculation unit 204 outputs the calculated front wheel braking and driving torque values ​​and rear wheel braking and driving torque values ​​to the MC-ECU 10.

[0037] Figure 4 is a diagram illustrating an example of processing in the vehicle behavior control device 2 according to the first embodiment. The processing shown in Figure 4 is executed repeatedly at a predetermined cycle.

[0038] As shown in Figure 4, the calculation unit 204 of the vehicle behavior control device 2 receives the vehicle speed acquired from the MC-ECU 10 by the acquisition unit 200 and determines whether the input vehicle speed is within the target range.

[0039] If the calculation unit 204 determines that the input vehicle speed is within the target range, it calculates the front wheel braking and driving torque value using the heave speed of vehicle 1 acquired by the acquisition unit 200 from the MC-ECU 10 and a preset first gain value. The calculation unit 204 also calculates the rear wheel braking and driving torque value by multiplying the calculated front wheel braking and driving torque value by a coefficient.

[0040] Here, the coefficient used to calculate the rear wheel braking torque value using the front wheel braking torque value is a constant that weights the front wheel braking torque value and makes the rear wheel braking torque value opposite in sign to the front wheel braking torque value. In Figure 4, it is denoted as "-a" (where a is a number greater than or equal to 0). The value of a is typically "1", but it can be adjusted according to, for example, the resonant frequency of the front wheel, the resonant frequency of the rear wheel, the wheelbase, etc.

[0041] The calculation unit 204 outputs the front wheel braking / driving torque value as a control value related to the drive of the front wheels of the vehicle 1, and the rear wheel braking / driving torque value as a control value related to the drive of the rear wheels of the vehicle 1, to the MC-ECU 10.

[0042] On the other hand, if the calculation unit 204 determines that the input vehicle speed is outside the target range, it calculates an intermediate value using the vehicle speed and pitch rate of vehicle 1 acquired from the MC-ECU 10 by the acquisition unit 200, and a second gain value.

[0043] The calculation unit 204 calculates the braking and driving torque value of the front wheels by adding an intermediate value using the pitch rate and an intermediate value using the pitch angle. Note that the intermediate value using the pitch rate and the intermediate value using the pitch angle can also be added with specific weightings as needed.

[0044] The calculation unit 204 multiplies the calculated front wheel braking and driving torque value by a coefficient to calculate the rear wheel braking and driving torque value.

[0045] The calculation unit 204 outputs the front wheel braking / driving torque value as a control value related to the drive of the front wheels of the vehicle 1, and the rear wheel braking / driving torque value as a control value related to the drive of the rear wheels of the vehicle 1, to the MC-ECU 10.

[0046] The MC-ECU10 controls the drive mechanism 21 using control values ​​received from the vehicle behavior control device 2. For example, the MC-ECU10 adds (or subtracts) the front wheel braking and driving torque values ​​received from the vehicle behavior control device 2 to the front wheel control values ​​it has calculated, and the rear wheel braking and driving torque values ​​received from the vehicle behavior control device 2 to the rear wheel control values ​​it has calculated. Based on the added control values, it controls the drive torque of the front wheels and the rear wheels.

[0047] Next, we will explain the behavioral control that the vehicle 1 receives as a result of the above-described operation of the vehicle behavior control device 2. As shown in Figure 5, we will explain using the example of when the vehicle 1 is traveling on the road surface and drives over a protrusion D on the road surface, starting with the front wheels and then moving to the rear wheels.

[0048] Figure 6A is a graph showing the temporal changes in stroke amount (vibration amount), pitch angle (pitch vibration), and heave amount (heave vibration) for two cases: a first case where the resonant frequency of the front wheels Fr = the resonant frequency of the rear wheels Rr, and a second case where the resonant frequency of the front wheels Fr < the resonant frequency of the rear wheels Rr, when vehicle 1, whose speed is within the target speed range, crosses the obstacle shown in Figure 5.

[0049] As can be seen from Figure 6A, in the second case, the resonant frequency Rr of the rear wheel is greater than the resonant frequency Fr of the front wheel, so the stroke amount of the rear wheel catches up to the stroke amount of the front wheel faster than in the first case. The pitch angle is calculated from the difference between the stroke amount of the front wheel and the stroke amount of the rear wheel. For this reason, pitch vibration is reduced in the second case compared to the first case. On the other hand, the heave amount is plotted as the smaller of the front wheel stroke amount and the rear wheel stroke amount at the same time. For this reason, heave vibration is increased in the second case compared to the first case.

[0050] Figure 6B is a graph showing the temporal changes in stroke amount, pitch angle, and heave amount for two cases: a first case where the resonant frequency of the front wheels Fr = the resonant frequency of the rear wheels Rr, and a second case where the resonant frequency of the front wheels Fr < the resonant frequency of the rear wheels Rr, when vehicle 1, whose speed is not within the target speed range (lower than the target speed), performs the obstacle shown in Figure 5.

[0051] As can be seen from Figure 6B, even in the second case, when the vehicle speed is below the target vehicle speed, the stroke amount of the rear wheels cannot keep up with the stroke amount of the front wheels because the vehicle speed is slow. For this reason, the pitch angle, which is the difference between the stroke amount of the front wheels and the stroke amount of the rear wheels, occurs over a certain period of time. On the other hand, heave vibration is reduced. Therefore, when the vehicle speed is below the target vehicle speed, pitch vibration is the main component of vibration in vehicle 1.

[0052] The impact on the passenger's perception can be greater from pitch vibration than from heave vibration due to factors such as large eye movements. Furthermore, while pitch vibration is the main component of vibration in vehicle 1 at speeds below the target speed, the heave vibration of vehicle 1 at the target speed is greater than the heave vibration of vehicle 1 at speeds below the target speed. Focusing on this point, the vehicle behavior control device 2 efficiently reduces pitch vibration and heave vibration by using different gain information depending on the vehicle speed.

[0053] Figure 7 is a table summarizing whether the pitch behavior and heave behavior of the vehicle increase or decrease, respectively, when the vehicle speed is within the target speed range and when it is not, in the second case where the resonant frequency of the front wheels Fr < the resonant frequency of the rear wheels Rr. As shown in Figure 7, in the second case, when the vehicle speed is within the target speed range, the pitch behavior decreases, but the heave behavior increases. On the other hand, when the vehicle speed is not within the target speed range, the pitch behavior increases, but the heave behavior decreases.

[0054] Based on the above, when the vehicle speed is within the target speed range, the vehicle behavior control device 2 according to the embodiment switches to the first gain information side that prioritizes reducing the heave vibration as shown in FIG. 4, and calculates the driving and braking torque values of the front wheels and the driving and braking torque values of the rear wheels at each time using the vehicle speed, parameters related to the heave, and the first gain information according to the waveform of the heave amount shown in FIG. 6A. Further, when the vehicle speed is not within the target speed range, the vehicle behavior control device 2 switches to the second gain information side that prioritizes reducing the pitch vibration as shown in FIG. 4, and calculates the driving and braking torque values of the front wheels and the driving and braking torque values of the rear wheels at each time using the vehicle speed, at least one parameter related to the pitch, and the second gain information according to the waveform of the pitch angle shown in FIG. 6A.

[0055] FIG. 8 is a diagram for explaining vehicle behavior control realized by the vehicle behavior control device 3 when the vehicle speed is not within the target speed range. In FIG. 8, F r represents the front wheel side, R r represents the rear wheel side, O represents the center of gravity position of the vehicle 1, I f represents the rotation center of the front wheels, θ if represents the instantaneous rotation center of the front wheels, J f represents the ground contact point of the front wheels, I r represents the rotation center of the rear wheels, θ ir represents the instantaneous rotation center of the rear wheels, J r represents the ground contact point of the rear wheels, respectively.

[0056] As shown in FIG. 8, when the driving torque of the front wheels is increased in a state where the instantaneous rotation center θ if of the front wheels is above the rotation center I f of the front wheels (upper left in FIG. 8), a force F 11 in the direction in which the front part of the vehicle body of the vehicle 1 sinks is generated due to the generation of the driving force F 12 . Further, when the driving torque of the rear wheels is decreased in a state where the instantaneous rotation center θ ir of the rear wheels is between the rotation center I f of the rear wheels and the ground contact point J (upper right in FIG. 8), a force F 21 in the direction in which the rear part of the vehicle body of the vehicle 1 floats is generated due to the generation of the braking force F 22 .

[0057] For example, if vehicle 1's front wheels ride up onto a bump on the road surface at a speed outside the target speed range, the instantaneous center of rotation θ of the front wheels if The center of rotation of the front wheel is I f It is located higher up, and the instantaneous center of rotation θ of the rear wheel ir The center of rotation of the rear wheel is I f Let's consider the case where the value is lower (for example, the state in which the first peak of the pitch angle occurs in the upper Fr stroke waveform and the middle pitch angle waveform in Figure 6B).

[0058] In such cases, the vehicle behavior control device 3 selects gain information according to the pitch angle waveform in the middle section of Figure 6B, for example, calculates a braking torque value that increases the driving torque of the front wheels and a braking torque value that decreases the driving torque of the rear wheels, and outputs them to the MC-ECU 10. The MC-ECU 10 uses the control values ​​received from the vehicle behavior control device 2 to control the drive mechanism 21.

[0059] Therefore, a force F acts in the direction that causes the front of the vehicle 1 to sink. 12 And a force F in the direction that causes the rear of the vehicle body of vehicle 1 to lift off the ground. 22 This generates a rotational moment M1 that rotates the body of vehicle 1 counterclockwise, thereby reducing the increase in Fr stroke and pitch angle caused by the front wheels riding up.

[0060] Similarly, when the driving torque of the front wheels is reduced (lower left of Figure 8) or increased (lower right of Figure 8), the opposite phenomenon occurs as shown in the upper left and upper right of Figure 8, respectively: a force F acts in the direction that causes the front of the vehicle 1 to lift. 32 And a force F acting in the direction that causes the rear of the vehicle body of vehicle 1 to sink. 42 This generates a rotational moment M2 that rotates the body of vehicle 1 clockwise, thereby reducing the increase in Fr stroke and pitch angle caused by the front wheels riding up.

[0061] As described above, the vehicle behavior control device 2 according to the first embodiment controls the behavior of the vehicle 1 and comprises an acquisition unit 200 and a calculation unit 204. The acquisition unit 200 acquires the vehicle speed from the MC-ECU 10. The calculation unit 204 uses different gain information according to the acquired vehicle speed to calculate the braking and driving torque values ​​of the front wheels of the vehicle 1 and the braking and driving torque values ​​of the rear wheels of the vehicle 1, and outputs the front wheel braking and driving torque values ​​and the rear wheel braking and driving torque values ​​to the MC-ECU 10, which acts as a control unit that controls the driving of the front wheels and the driving of the rear wheels. The MC-ECU 10 controls the drive mechanism 21 using the braking and driving torque values ​​received from the vehicle behavior control device 2.

[0062] According to the vehicle behavior control device 2, for example, gain information that prioritizes reducing heave vibration or gain information that prioritizes reducing pitch vibration can be used according to the acquired vehicle speed. Therefore, the vehicle behavior control device 2 does not require a unit that controls the amount of air in the air spring according to the vehicle speed, and the pitch vibration and heave vibration of the vehicle 1 can be efficiently reduced by the driving force of the vehicle 1. As a result, a vehicle behavior control device with higher responsiveness and durability compared to conventional devices can be provided.

[0063] Furthermore, if the acquired vehicle speed is within the target range (target speed range), the calculation unit 204 uses the gain information related to heave, the vehicle speed, and the heave parameters (heave speed) acquired from vehicle 1 to calculate the braking and driving torque values ​​for the front wheels and the rear wheels. If the acquired vehicle speed is lower or higher than the target range (target speed range), the calculation unit 204 uses the gain information related to pitch, the vehicle speed, and at least one pitch parameter (pitch rate, pitch angle) acquired from vehicle 1 to calculate the braking and driving torque values ​​for the front wheels and the rear wheels.

[0064] Therefore, the vehicle behavior control device 2 can efficiently reduce pitch vibration and heave vibration by using gain information that prioritizes heave vibration reduction when the vehicle speed is within the target speed range, and by using gain information that prioritizes pitch vibration reduction when the vehicle speed is outside the target speed range.

[0065] (Second Embodiment) Next, the vehicle behavior control device 2 according to the second embodiment will be described. The vehicle behavior control device 2 according to the first embodiment calculated control values ​​related to driving using gain information that was switched according to the vehicle speed. In contrast, the vehicle behavior control device 2 according to the second embodiment calculates control values ​​related to driving using gain information whose gain value changes according to the vehicle speed. In the following, only the configurations that differ from the vehicle behavior control device 2 according to the first embodiment will be described.

[0066] Figure 9 is a diagram illustrating an example of the control flow performed by the vehicle behavior control device according to the second embodiment. The process shown in Figure 9 is executed repeatedly at a predetermined cycle.

[0067] As shown in Figure 9, the calculation unit 204 of the vehicle behavior control device 2 receives the vehicle speed acquired from the MC-ECU 10 by the acquisition unit 200 and determines whether the input vehicle speed is within the target range.

[0068] The calculation unit 204 calculates a first intermediate value using the vehicle speed of vehicle 1 acquired by the acquisition unit 200 from the MC-ECU 10, the heave speed, and the first gain information. The calculation unit 204 also calculates a second intermediate value using the vehicle speed of vehicle 1 acquired by the acquisition unit 200 from the MC-ECU 10, the pitch rate, the pitch angle, and second gain information different from the first gain information.

[0069] Here, the first gain information according to the second embodiment is information defined such that the gain changes according to the vehicle speed. The first gain information is, for example, a map, graph, function, etc., that defines the correspondence between vehicle speed and gain such that the gain is set to 0 when the vehicle speed is outside the target vehicle speed range, and the gain increases as the vehicle speed approaches the median of the target vehicle speed range.

[0070] Furthermore, the second gain information according to the second embodiment is information different from the first gain information, and is defined such that the gain changes according to the vehicle speed. The second gain information is, for example, a map, graph, function, etc., that defines the correspondence between vehicle speed and gain such that the gain is 0 when the vehicle speed is within the target vehicle speed range, and the gain becomes smaller as the vehicle speed approaches the median of the target vehicle speed range.

[0071] Note that in Figure 9, for the sake of explanation, an example is shown where the same second gain information is used for both the gain with pitch rate and vehicle speed as input and the gain with pitch angle and vehicle speed as input. Figure 9 is merely an example, and different types of second gain information can be used for each of the gains with pitch rate and vehicle speed as input and the gain with pitch angle and vehicle speed as input, as needed.

[0072] The calculation unit 204 calculates the braking and driving torque value of the front wheels by, for example, adding the first intermediate value and the second intermediate value. The calculation unit 204 also calculates the braking and driving torque value of the rear wheels by multiplying the braking and driving torque value of the front wheels by a coefficient.

[0073] Here, the coefficient is a constant used to weight the braking and driving torque values ​​of the front wheels, so that the braking and driving torque values ​​of the rear wheels have the opposite sign to those of the front wheels. In Figure 9, it is denoted as "-a" (where a is a number greater than or equal to 0, typically 1). The value of a can be adjusted according to, for example, the resonant frequency of the front wheels, the resonant frequency of the rear wheels, the wheelbase, etc.

[0074] The calculation unit 204 outputs the front wheel braking / driving torque value as a control value related to the drive of the front wheels of the vehicle 1, and the rear wheel braking / driving torque value as a control value related to the drive of the rear wheels of the vehicle 1, to the MC-ECU 10.

[0075] The MC-ECU10 controls the drive mechanism 21 using control values ​​received from the vehicle behavior control device 2.

[0076] According to the vehicle behavior control device 2, the calculation unit 204 calculates the braking and driving torque values ​​for the front wheels and the braking and driving torque values ​​for the rear wheels using, for example, first gain information which defines the relationship between vehicle speed and gain such that the gain increases as the vehicle speed approaches the median of the target vehicle speed range, second gain information which defines the relationship between vehicle speed and gain such that the gain decreases as the vehicle speed approaches the median of the target vehicle speed range, and at least one parameter related to the pitch of the vehicle 1 (pitch rate, pitch angle).

[0077] Therefore, when the vehicle speed is within the target speed range, the system can calculate the front and rear wheel braking / driving torque values ​​in which pitch vibration reduction takes precedence over heave vibration reduction, and use these values ​​to control the driving torque. Furthermore, when the vehicle speed is outside the target speed range, the system can calculate the front and rear wheel braking / driving torque values ​​in which heave vibration reduction takes precedence over pitch vibration reduction, and use these values ​​to control the driving torque. As a result, a vehicle behavior control system with even greater responsiveness and flexibility can be provided.

[0078] (Third embodiment) Next, a vehicle behavior control device 2 according to the third embodiment will be described.

[0079] Generally, in vehicle 1, heavy components such as the engine are located at the front. Therefore, the movement of vehicle 1 is greater when the rear wheels ride over a bump in the road surface. Also, the rear seats of vehicle 1 move significantly when the rear wheels ride over a bump in the road surface.

[0080] Therefore, when the rear-seat priority mode is selected, the vehicle behavior control device 2 according to the third embodiment performs control to increase the reduction of heave vibration in accordance with the timing when the rear wheels ride over a bump in the road surface. In the following description, only the configurations that differ from those of the vehicle behavior control device 2 according to the second embodiment will be explained.

[0081] Figure 10 shows an example of the pitch rate waveform of vehicle 1 when vehicle 1 crosses the obstacle shown in Figure 5. In Figure 10, the period t is calculated from when the front wheels begin to ride onto the bump in the road surface until they pass over the bump. f The period of time from when the rear wheel begins to ride over a bump in the road surface until it passes over the bump. f These are indicated by shading. Furthermore, the period T from the start of the front wheel riding over the protrusion to the start of the rear wheel riding over the protrusion can be calculated using the wheelbase / vehicle speed.

[0082] When the rear-seat priority mode is selected, the vehicle behavior control device 2 controls the period t from when the rear wheels begin to ride onto a bump in the road surface (as shown in Figure 10) until they pass over the bump. r In this system, control is implemented to further reduce heave vibrations. The rear-seat priority mode can be selected, for example, by pressing a button on the passenger's device.

[0083] For example, when the rear-seat priority mode is selected, consider the case where, as shown in Figure 5, vehicle 1 is driving on the road surface and drives over a protrusion D on the road surface, starting with the front wheels and then moving to the rear wheels to cross over the protrusion D. In such a case, the vehicle behavior control device 2 performs behavior control according to Figure 9, for example, but from the moment the front wheels start to drive over until a preset period has elapsed, it switches from the first gain information to a third gain information with a higher gain value (i.e., a higher heave vibration reduction rate) compared to the first gain information, and performs behavior control according to Figure 9.

[0084] According to the above configuration, when the rear-seat priority mode is selected, the gain information related to heave is increased. This allows for a further reduction in heave vibration, for example, when the vehicle drives over a bump in the road surface. As a result, it is possible to achieve vehicle behavior control that reduces vibration in the rear seats and provides a more comfortable ride without adding any special units.

[0085] (Variation 1) In the embodiments described above, the vehicle was assumed to have four wheels. However, the vehicle behavior control device can be applied to vehicles other than four-wheeled vehicles, such as motorcycles and other two-wheeled vehicles, and trucks and other vehicles with four or more wheels, as long as the front and rear wheels are capable of being driven and controlled. (Modification 2) In each of the embodiments described above, an example was explained in which the MC-ECU10 calculates parameters related to the heave of the vehicle 1 and at least one parameter related to the pitch of the vehicle 1. In contrast, the SC-ECU11 may acquire detection values ​​from at least three acceleration sensors and calculate parameters related to the heave of the vehicle 1 and at least one parameter related to the pitch of the vehicle 1 based on these values.

[0086] The program that causes a computer to execute the processing necessary to realize the functions of the vehicle behavior control device described above can be provided as an installable or executable file recorded on a computer-readable recording medium such as a CD (Compact Disc)-ROM, flexible disk (FD), CD-R (Recordable), or DVD (Digital Versatile Disk). Furthermore, this program may be provided or distributed via a network such as the Internet.

[0087] Although embodiments of the present invention have been described above, the embodiments and their modifications described herein are merely examples and are not intended to limit the scope of the invention. The novel embodiments and modifications described herein can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and modifications described herein are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0088] [Summary of this embodiment] This embodiment comprises at least the following configurations.

[0089] The vehicle behavior control device (2) according to the embodiment is a vehicle behavior control device (2) that controls the behavior of a vehicle (1), and comprises an acquisition unit (200) that acquires the vehicle speed, and a calculation unit (204) that uses different gain information according to the acquired vehicle speed to calculate the braking and driving torque values ​​of the front wheels of the vehicle (1) and the braking and driving torque values ​​of the rear wheels of the vehicle (1), and outputs the front wheel braking and driving torque values ​​and the rear wheel braking and driving torque values ​​to a control unit (10) that controls the driving of the front wheels and the driving of the rear wheels.

[0090] According to the vehicle behavior control device 2, for example, gain information that prioritizes reducing heave vibration or gain information that prioritizes reducing pitch vibration can be used depending on the acquired vehicle speed. Therefore, the vehicle behavior control device 2 does not require air springs or units that control the amount of air in the air springs according to the vehicle speed, and the pitch vibration and heave vibration of the vehicle 1 can be efficiently reduced by the driving force of the vehicle 1. As a result, a vehicle behavior control device (2) with higher responsiveness and durability compared to conventional devices can be provided.

[0091] The calculation unit (204) of the vehicle behavior control device (2) according to the embodiment calculates the braking and driving torque values ​​of the front wheels and the rear wheels using gain information related to heave, the vehicle speed, and parameters related to heave obtained from the vehicle (1) if the acquired vehicle speed is within the target range, and calculates the braking and driving torque values ​​of the front wheels and the rear wheels using gain information related to pitch, the vehicle speed, and at least one parameter related to pitch obtained from the vehicle (1) if the acquired vehicle speed is lower or higher than the target range.

[0092] Therefore, according to the vehicle behavior control device (2), when the vehicle speed is within the target speed range, gain information prioritizing heave vibration reduction is used, and when the vehicle speed is outside the target speed range, gain information prioritizing pitch vibration reduction is used, thereby efficiently reducing both pitch vibration and heave vibration.

[0093] The calculation unit (204) of the vehicle behavior control device (2) according to the embodiment calculates the braking and driving torque values ​​of the front wheels and the braking and driving torque values ​​of the rear wheels using first gain information that changes according to the vehicle speed, the vehicle speed, parameters relating to the heave of the vehicle (1), second gain information that changes according to the vehicle speed and is different from the first gain information, and at least one parameter relating to the pitch of the vehicle (1).

[0094] Therefore, when the vehicle speed is within the target speed range, for example, the braking and driving torque values ​​for the front wheels and rear wheels where pitch vibration reduction takes precedence over heave vibration reduction can be calculated, and the driving torque can be controlled using these values. Also, when the vehicle speed is outside the target speed range, for example, the braking and driving torque values ​​for the front wheels and rear wheels where heave vibration reduction takes precedence over pitch vibration reduction can be calculated, and the driving torque can be controlled using these values. As a result, a vehicle behavior control device with even greater responsiveness and flexibility can be provided.

[0095] In the vehicle behavior control device (2) according to the embodiment, the calculation unit (204) increases the gain information related to heave when the rear seat priority mode is selected.

[0096] Therefore, when the rear-seat priority mode is selected, heave vibrations can be further reduced, for example, when the vehicle drives over a bump in the road surface. As a result, it is possible to achieve vehicle behavior control that reduces vibrations in the rear seats and provides a more comfortable ride without adding any special units. [Explanation of Symbols]

[0097] 1...Vehicle, 2...Vehicle behavior control device, 10...MC-ECU (control unit), 11...SC-ECU, 12...Communication I / F, 13...User I / F, 14...On-board sensors, 14A, 14B...Accelerometers, 14C...Vehicle height sensor, 14D...Wheel speed sensor, 20...CAN, 21...Drive mechanism, 22...Braking mechanism, 23...Steering mechanism, 24...Suspension mechanism, 200...Acquisition unit, 204...Calculation unit

Claims

1. In a vehicle behavior control system that controls the behavior of a vehicle, A unit that acquires vehicle speed, A calculation unit calculates the braking and driving torque values ​​of the front wheels and the rear wheels of the vehicle using gain information that varies according to the acquired vehicle speed, and outputs the braking and driving torque values ​​of the front wheels and the rear wheels to a control unit that controls the driving of the front wheels and the driving of the rear wheels. A vehicle behavior control system equipped with the following features.

2. The aforementioned arithmetic unit, If the acquired vehicle speed falls within the target range, the braking and driving torque values ​​of the front wheels and the rear wheels are calculated using the gain information related to heave, the vehicle speed, and the heave parameters acquired from the vehicle. If the acquired vehicle speed is lower or higher than the target range, the braking and driving torque values ​​of the front wheels and the rear wheels are calculated using the gain information related to the pitch, the vehicle speed, and at least one parameter related to the pitch acquired from the vehicle. The vehicle behavior control device according to claim 1.

3. The calculation unit calculates the braking and driving torque values ​​of the front wheels and the braking and driving torque values ​​of the rear wheels using first gain information that changes according to the vehicle speed, the vehicle speed, parameters relating to the vehicle's heave, second gain information that changes according to the vehicle speed and is different from the first gain information, and at least one parameter relating to the vehicle's pitch. The vehicle behavior control device according to claim 1.

4. The calculation unit increases the gain information related to the heave when the rear seat priority mode is selected. The vehicle behavior control device according to claim 2 or 3.

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