JP4561189B2 - Vehicle motion control device - Google Patents

Description

  The present invention relates to a vehicle motion control device that controls the motion of a vehicle capable of independently driving front and rear wheels and capable of independently driving left and right wheels for at least one of the front and rear wheels.

  The posture angle of the vehicle (for example, the side slip angle β at the center of gravity of the vehicle) and the turning amount (for example, the lateral acceleration Yg of the vehicle) affect the driver's visibility and movement of the viewpoint, and there is a range where the driver can easily drive.

Therefore, conventionally, for example, in a vehicle in which the braking force of each wheel can be adjusted individually, a technique for suitably controlling the turning amount during braking has been proposed (see Patent Document 1).
JP-A-6-24304

  However, in the past, in a vehicle that can adjust the difference between the left and right wheel driving force and the front and rear wheel driving force distribution, no technology has been proposed for suitably controlling the attitude angle of the vehicle, and there is still room for improvement in improving the driver's maneuverability. is there.

  The present invention has been made paying attention to such a conventional problem, and in a vehicle capable of controlling the left and right wheel driving force difference and the front and rear wheel driving force distribution, not only the turning amount of the vehicle but also the attitude angle is provided. An object of the present invention is to provide a vehicle motion control device that improves the maneuverability of a driver by controlling.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

The present invention is a vehicle motion control device that controls the motion of a vehicle that can independently drive front and rear wheels and that can independently drive left and right wheels for at least one of the front and rear wheels, and detects a steering operation angle θ. Based on the steering angle detection means (25; step S10), the vehicle speed detection means (22 to 24; steps S10 and S20) for detecting the vehicle speed V, the target turning of the vehicle based on the steering wheel operation angle θ and the vehicle speed V. The target behavior determining means (steps S40 and S50) for determining the amount tYg and the target posture angle tβ, the turning amount detecting means (100; step S10) for detecting the turning amount Yg of the vehicle, and the turning amount detecting means. When the absolute value of the detected turning amount Yg is larger than the reference value Ygth, the left and right wheel driving force difference ΔT and the front and rear are based on the target turning amount tYg and the target posture angle tβ. When the wheel driving force distribution η is set, and the absolute value of the detected turning amount Yg is smaller than the reference value Ygth, driving force distribution determining means for setting the left and right wheel driving force difference ΔT based on the target turning amount tYg (step) S70, S80), and vehicle behavior control means (steps S90, S100) for controlling the vehicle behavior by controlling the left and right wheel driving force difference ΔT and the front and rear wheel driving force distribution η.

  According to the present invention, when the turning amount of the vehicle is detected and the absolute value of the detected turning amount is larger than the reference value, the left and right wheel driving force difference and the front and rear wheel driving force are based on the target turning amount and the target attitude angle. The distribution is set, and when the detected absolute value of the turning amount is smaller than the reference value, the left and right wheel driving force difference is set based on the target turning amount.

  According to the inventors of the present invention, the turning amount (lateral acceleration) and the posture angle (side slip angle) hardly change even when the driving force front wheel distribution increases or decreases when the turning amount is small, and increases or decreases the difference between the left and right driving forces. It changes with it. It was also found that as the turning amount increases, it also changes as the driving force front wheel distribution increases or decreases.

  Therefore, by changing the setting method of the left and right wheel driving force difference and the front and rear wheel driving force distribution according to the detected turning amount as described above, the vehicle behavior can be appropriately controlled, and the driver's maneuverability is improved. is there.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(basic way of thinking)
First, in order to facilitate understanding of the present invention, a basic concept will be described.

In a vehicle (details will be described later with reference to FIG. 3) in which the left and right wheel driving force difference ΔT and the front and rear wheel driving force distribution (driving force front wheel distribution η) can be individually controlled, the vehicle speed V and the steering wheel operation angle θ are constant. When the left and right wheel driving force difference ΔT and the driving force front wheel distribution η are changed in the state maintained in the state, the vehicle's lateral acceleration Yg (unit: m / s ² ) that is the turning amount and the vehicle's center of gravity that is the attitude angle The side slip angle β (unit: rad) is as shown in FIGS. Here, the driving force is a driving force output by the vehicle in order to compensate for running resistance such as air resistance. FIG. 1 shows a case where the steering wheel operation angle θ is small and the turning amount (lateral acceleration Yg) is small, and FIG. 2 shows a case where the steering wheel operation angle θ is large and the turning amount (lateral acceleration Yg) is large. In both FIG. 1 and FIG. 2, the horizontal driving force difference ΔT (unit: N) is taken on the horizontal axis, and the front wheel distribution η (unit:%) of the driving force is taken on the vertical axis. The points where the lateral acceleration Yg and the side slip angle β are equal are connected. In both figures, the lateral acceleration Yg is indicated by a solid line, and the skid angle β is indicated by a broken line. Further, as shown in FIG. 2, if the left / right driving force difference ΔT → large and the driving force front wheel distribution η → small, the turning amount becomes excessive and vehicle control becomes difficult.

  As shown in FIG. 1, the lateral acceleration Yg and the side slip angle β hardly change even if the driving force front wheel distribution η increases or decreases when the steering wheel operation angle θ is small and the turning amount (lateral acceleration Yg) is small. It changes with the increase / decrease in the left / right driving force difference ΔT. In addition, as shown in FIG. 2, when the steering wheel operation angle θ increases and the turning amount (lateral acceleration Yg) increases, the steering force angle changes as the driving force front wheel distribution η increases or decreases.

  Thus, in a vehicle in which the left and right wheel driving force difference ΔT and the driving force front wheel distribution η can be individually adjusted, the turning amount (lateral acceleration Yg in the present invention) and posture angle (side slip angle β in the present invention) are: When the steering wheel operation angle θ is small and the turning amount is small, it is almost determined by the left and right wheel driving force difference ΔT, and as the steering wheel operation angle θ increases and the turning amount increases, the left and right wheel driving force difference ΔT and the driving force front wheel It is determined by both of the distribution η.

  The present invention is based on the above findings found through repeated research by the inventors, in a vehicle that can individually adjust the left and right wheel driving force difference ΔT and the front and rear wheel driving force distribution (driving force front wheel distribution η). When the steering wheel operation angle θ is small and the turning amount is small, the turning amount is controlled based on the left and right wheel driving force difference ΔT. When the steering wheel operation angle θ is increased and the turning amount is large, By controlling the turning amount and the posture angle based on the left and right wheel driving force difference ΔT and the front and rear wheel driving force distribution (driving force front wheel distribution η), the turning amount and the posture angle are appropriately controlled, and the driver's It is intended to improve maneuverability. The specific contents will be described below.

(First embodiment)
FIG. 3 is a block diagram showing a first embodiment of the mechanical configuration of the electric vehicle.

  In the electric vehicle shown in FIG. 3, the left front wheel 11 and the right front wheel 12 are independently driven by the motor 2 driven by the power supplied from the battery 9, the left rear wheel 13 is driven by the motor 3, and the right rear wheel 14 is driven independently by the motor 4. To drive. The radii of the wheels 11 to 14 are all equal to R, and the reduction ratio is 1, that is, the motors and the wheels are directly connected.

  The motors 2 to 4 are AC machines capable of powering operation and regenerative operation such as a three-phase synchronous motor and a three-phase induction motor, and the battery 9 is a nickel hydrogen battery or a lithium ion battery. The inverters 32 to 34 convert the alternating current generated by the motors 2 to 4 into a direct current and charge the battery 9, or convert the direct current discharged by the battery 9 into an alternating current and supply the alternating current to the motors 2 to 4. The speed of each wheel is detected by wheel speed sensors 22 to 24, and the detected rotation speed of each wheel is transmitted to the controller 8.

  The lateral acceleration of the vehicle is detected by the acceleration sensor 100 attached to the center of gravity of the vehicle, the yaw rate of the vehicle is detected by the yaw rate sensor 101, and the detected lateral acceleration and yaw rate of the vehicle are transmitted to the controller 8.

  The steering angles of the front wheels 11 and 12 are mechanically adjusted via the steering gear 15 by the steering of the handle 5 by the driver.

  The rotation angle of the handle 5 by the driver is detected by the handle angle sensor 25, and the depression amounts of the accelerator pedal 6 and the brake pedal 7 are detected by the accelerator stroke sensor 26 and the brake stroke sensor 27, respectively, and transmitted to the controller 8.

  The controller 8 includes a CPU, a ROM, a RAM, an interface circuit, an inverter circuit, and the like, and is detected by a wheel speed sensor 22 to 24, a handle angle sensor 25, an accelerator stroke sensor 26, a brake stroke sensor 27, an acceleration sensor 100, a yaw rate sensor 101, and the like. The received signals are received, and control such as distributing torque to the motors 2 to 4 is performed based on these signals. Note that, as described above, in the present invention, in the vehicle in which the left and right wheel driving force difference ΔT and the front and rear wheel driving force distribution (driving force front wheel distribution η) can be individually adjusted, the torques of the motors 2 to 4 according to the steering wheel operation angle θ. By appropriately controlling the distribution, the amount of turn and the attitude angle are controlled to improve the driver's maneuverability.

  In the following, specific control logic in the controller 8 will be described with reference to a flowchart.

  FIG. 4 is a flowchart showing a first embodiment of the vehicle motion control apparatus according to the present invention, and shows torque distribution control to the motors 2 to 4 executed by the controller 8 in the electric vehicle shown in FIG.

In step S10, the rotational speeds ω1, ω2, ω3, and ω4 (unit: rad / s) of the wheels 11 to 14 are detected by the wheel speed sensors 22 to 24, respectively, and multiplied by the radius R of each wheel to obtain the speeds V1 and V2. , V3, V4 (unit: m / s). Further, the accelerator stroke sensor 26 detects the depression amount AP of the accelerator pedal 6, the brake stroke sensor 27 detects the depression amount BP of the brake pedal 7, and the handle angle sensor 25 rotates the rotation angle θ (unit: rad). , The lateral acceleration Yg (unit: m / s ² ) of the vehicle is detected by the acceleration sensor 100, and the yaw rate γ (unit: rad / s) is detected by the yaw rate sensor 101. The speeds V1 to V4 are positive in the vehicle forward direction, the steering wheel operation angle θ is positive in the counterclockwise direction when viewed from the driver, and the lateral acceleration Yg is the direction from the vehicle center of gravity to the turning center when the vehicle turns left. The yaw rate γ is positive and the counterclockwise direction is positive when the vehicle is viewed from above. In the present embodiment, the lateral acceleration Yg corresponds to the turning amount of the vehicle in the claims.

In step S20, the vehicle speed V (unit: m / s) is obtained as in equation (1). Further, the longitudinal acceleration Xg (unit: m / s ² ) of the vehicle is obtained as in equation (2).

V = (V1 + V2 + V3 + V4) ÷ 4 Equation (1)
Xg = (V−Vo) ÷ ts (2)

  In equation (2), ts is the calculation cycle (unit: s) in the flowchart of FIG. 4 in the controller 8, and Vo is V one cycle before set in step S100 described later (initial at the start of calculation). The value 0 is set). Note that V is positive in the vehicle forward direction, and the longitudinal acceleration Xg is positive in the direction in which the vehicle accelerates forward.

  In step S30, the driver's required driving force tT for the electric vehicle is obtained as in equation (3).

      tT = tTa + tTb (3)

  TTa in the equation (3) is a required driving force corresponding to the accelerator pedal depression amount AP and the vehicle speed V, and is set based on the required driving force map. This required driving force map is obtained by recording the required driving force corresponding to the accelerator pedal depression amount AP in the ROM of the controller 8 in advance. FIG. 5 shows an example.

  Further, tTb in the expression (3) is a required braking force corresponding to the brake pedal depression amount BP, and is set based on the required braking force map. This required braking force map is obtained by recording the required braking force corresponding to the brake pedal depression amount BP in the ROM of the controller 8 in advance. FIG. 6 shows an example. Note that tT, tTa, and tTb are all positive in the direction in which the vehicle is accelerated forward.

  In step S40, the target lateral acceleration tYg of the vehicle is set based on the target turning amount map from the rotation angle θ of the handle 5 and the vehicle speed V. This target turning amount map is obtained by storing in advance the target lateral acceleration tYg corresponding to the steering wheel operation angle θ and the vehicle speed V in the ROM of the controller 8, and an example is shown in FIG. Needless to say, the target lateral acceleration tYg is set to a value that the vehicle of FIG. 1 can output at the current steering angle θ and the vehicle speed V.

  In step S50, the target side slip angle tβ at the center of gravity of the vehicle is set based on the target attitude angle map from the steering wheel operation angle θ and the vehicle speed V. This target posture angle map is obtained by storing the target side slip angle tβ corresponding to the steering wheel operation angle θ and the vehicle speed V in the ROM of the controller 8 in advance. FIG. 8 shows an example. In the present embodiment, the side slip angle β of the center of gravity of the vehicle corresponds to the posture angle of the vehicle in the claims. Needless to say, the target side slip angle tβ is set to a value that the vehicle can output at the current steering angle θ and the vehicle speed V.

In step S60, if the absolute value | Yg | of the lateral acceleration of the vehicle is greater than or equal to the reference value Ygth, the process proceeds to step S70, and if smaller than Ygth, the process proceeds to step S80. The reference value Ygth is a threshold value for switching maps, and this value is determined in advance by experiment. For example, in this embodiment, it is set to 1 m / s ² .

  In step S70, the distribution ratio η (%) of the required driving torque tT determined in step S30 from the target lateral acceleration tYg and the target side slip angle tβ to the front wheels and the left and right wheel driving force difference ΔT are set in each wheel driving force distribution map. Set based on. The right and left wheel driving force difference ΔT is positive when the right wheel driving force is equal to or greater than the left wheel driving force.

  Each wheel driving force distribution map is a map as shown in FIG. 9 as an example, and the driving force front wheel distribution for realizing the target lateral acceleration tYg and the target skid angle tβ for each steering wheel operation angle θ and vehicle speed V. η and left and right wheel driving force difference ΔT are stored. Each wheel driving force distribution map is created by the flowchart of FIG. 11 and will be described in detail later.

  Here, based on the steering wheel operation angle θ and the vehicle speed V, it is assumed that each wheel driving force distribution map shown in FIG. The target lateral acceleration tYg and the target side slip angle tβ obtained in steps S40 and S50 are applied to this FIG. 9 to determine the driving force front wheel distribution η and the left and right wheel driving force difference ΔT. In this example, there are two points A and B that can realize the target lateral acceleration tYg and the target skid angle tβ obtained in steps S40 and S50. In such a case, the point at which the left and right wheel driving force difference ΔT is the smallest is selected. In this example, the point A having a small ΔT is selected, and the point B having a large ΔT is not selected.

  In this way, the driving force front wheel distribution η and the left and right wheel driving force difference ΔT are set from the target lateral acceleration tYg and the target side slip angle tβ.

  In step S80, the left and right wheel driving force difference ΔT is set from the target lateral acceleration tYg based on the left and right wheel driving force difference map, and the driving force front wheel distribution η is set to the front wheel weight distribution ηf when the vehicle is stationary. To do.

  This left and right wheel driving force difference map is a map as shown in FIG. 10 as an example, and stores a left and right wheel driving force difference ΔT that realizes a target lateral acceleration tYg for each steering operation angle θ. This left and right wheel driving force difference map is created by the flowchart of FIG. 11 and will be described in detail later.

  When | Yg | is smaller than Ygth, the driving force front wheel distribution η has almost no sensitivity to Yg and β as shown in FIG. 1, so that an arbitrary value can be used for the driving force front wheel distribution η. . The front wheel weight distribution ηf when the vehicle is stationary as described above may be used, or the driving force front wheel distribution η may be determined so that the total power saving of each drive motor is minimized.

  In step S90, the driving torques Tm2 to Tm4 of the motors 2 to 4 are set according to the equations (4) to (6) from the driving force front wheel distribution η and the left and right wheel driving force difference ΔT.

Tm2 = (tTa × η) × R (4)
Tm3 = ((tTa × (1-η)) ÷ 2-ΔT ÷ 2) × R (5)
Tm4 = ((tTa × (1−η)) ÷ 2 + ΔT ÷ 2) × R (6)

  In step S100, control is performed so that the motors 2 to 4 output Tm2 to Tm4, and the current vehicle speed V is set to Vo.

  Next, the flowchart of FIG. 11 for determining each wheel driving force distribution map and the left and right wheel driving force difference map in the flowchart of FIG. 4 will be described. The flowchart of FIG. 11 is executed in advance using the vehicle simulation model or actual vehicle of FIG. 3 before the controller 8 is manufactured.

  In step S210, 0 is set to the vehicle speed V.

  In step S220, dV (unit: m / s) is added to the vehicle speed V. This dV is a positive value, and even if the vehicle speed V changes by dV, the change in the vehicle response due to the steering wheel operation angle θ, the left and right wheel driving force difference ΔT, etc. is set to a sufficiently small value for the driver.

  In step S230, 0 is set to the handle operating angle θ.

  In step S240, dθ (unit: rad) is added to the handle operating angle θ. This dθ is a positive value, and at any V, ΔT, η that the vehicle of FIG. 3 can take, the change in the response of the vehicle due to the change in the steering operation angle θ by dθ is set to a sufficiently small value for the driver.

  In step S250, at the vehicle speed V and the steering wheel operation angle θ set in the previous steps, the left and right wheel driving force difference ΔT is changed in the range of 0 to ΔTmax, and the driving force front wheel distribution η is changed in the range of 0 to 100, respectively. However, the vehicle shown in FIG. 3 is actually or simulated, and the lateral acceleration Yg and the skid angle β at each (ΔT, η) are obtained. Then, taking the left and right wheel driving force difference ΔT and the driving force front wheel distribution η as the respective axes, the lateral acceleration Yg becomes equal (ΔT, η), and the side slip angle β becomes equal (ΔT, η), respectively. As a result, FIG. 12A is created. The map of FIG. 12A is a wheel driving force distribution map at the currently set vehicle speed V and steering wheel operation angle θ.

  Here, when the left and right wheel driving force difference ΔT is changed in the range of 0 to ΔTmax and the driving force front wheel distribution η is changed in the range of 0 to 100, the lateral acceleration Yg and the side slip of each obtained wheel driving force distribution map are obtained. The interval between the contour lines of the angle β is set sufficiently fine so that the driver does not feel uncomfortable even if the lateral acceleration Yg and the skid angle β change with the interval between the contour lines. ΔTmax is a value obtained by subtracting the minimum output Tm3min (V, θ, η) of the motor 3 from the maximum output Tm4max (V, θ, η) of the motor 4 at the currently set V, θ, η. .

  In step S260, in each wheel driving force distribution map set in step S250, the left and right wheel driving force difference ΔT and the lateral acceleration Yg on the constant distribution line of the front wheel weight distribution ηf when the vehicle is stationary are shown in FIG. Create b). The map of FIG. 12B is a left-right wheel driving force difference map at the currently set vehicle speed V and steering wheel operation angle θ.

  In step S270, the process proceeds to step S240 until the handle operation angle θ is equal to or greater than θmax, and the above process is repeated. When the handle operation angle θ is equal to or greater than θmax, the process proceeds to step S280. Note that θmax is the maximum rotation angle of the handle 5, that is, the cut angle when the handle 5 is fully turned counterclockwise.

  In step S280, the process proceeds to step S220 until the vehicle speed V becomes equal to or higher than Vmax, and the above process is repeated. When the vehicle speed V becomes equal to or higher than Vmax, the process proceeds to step S290.

  In step S290, the steps from S210 to S280 are set such that “dθ” is set to “−dθ” in step S240, “ΔTmax = Tm4max−Tm3min” is set to “ΔTmin = Tm4min−Tm3max” in step S250, and “θmax” is set in step S270. The above is again performed as “θmin or less”, and each wheel driving force distribution map and left and right wheel driving force difference maps at each vehicle speed V and steering wheel operation angle θ are obtained. ΔTmin is a value obtained by subtracting the maximum output Tm3max (V, θ, η) of the motor 3 from the minimum output Tm4min (V, θ, η) of the motor 4 at the currently set V, θ, η. , Θmin is a minimum rotation angle of the handle 5, that is, a cutting angle when the steering wheel 5 is fully turned clockwise.

  That is, each wheel driving force distribution map and left and right wheel driving force difference maps are created when the steering wheel operation angle θ is positive until step S280, and when the steering wheel operation angle θ is negative in step S290.

  As described above, the wheel driving force distribution map and the left and right wheel driving force difference maps at the vehicle speed V and the steering operation angle θ that can be taken by the vehicle of FIG. 3 are created as shown in FIG.

  According to this embodiment, in a vehicle capable of adjusting the left and right wheel driving force difference between one or both of the front wheels and the rear wheels and the front and rear wheel driving force distribution, when the turning amount is small, it corresponds to the vehicle speed and the handle operating angle. The left and right wheel driving force difference is determined so as to realize the target turning amount, and when the turning amount is large, the left and right wheel driving force difference is determined so as to realize the target turning amount and the target attitude angle corresponding to the vehicle speed and the steering angle. The front and rear wheel driving force distribution is determined. With such a configuration, when the turning amount that requires more posture angle control is large, the posture angle of the vehicle can be controlled within a range in which the driver can easily steer, and the maneuverability can be improved. Even in a vehicle in which the steering angle of each vehicle wheel cannot be adjusted, the attitude angle of the vehicle can be controlled, so that cost reduction can be expected.

(Second Embodiment)
FIG. 13 is a flowchart showing a second embodiment of the vehicle motion control device according to the present invention. In the following description, the same reference numerals are given to portions that perform the same functions as those in the above-described embodiment, and overlapping descriptions are omitted as appropriate.

  The present embodiment is intended to realize the turning amount by feedback control.

  Steps S10 to S40 are the same as those in the first embodiment.

  In step S81, a deviation ΔYg between the target turning amount (target lateral acceleration tYg) and the actually detected turning amount (lateral acceleration Yg) is calculated.

  In step S82, feedback gains k1 and k2 are set based on FIG. Details will be described later.

  In step S300, the left and right wheel driving force difference ΔT and the driving force front wheel distribution η are set as in equations (7) to (8).

ΔT = k1 × ΔYg (7)
η = k2 × ΔYg (8)
And the drive torque Tm2-Tm4 of the motors 2-4 is set (step S90), and the motors 2-4 are controlled (step S100).

  Here, a supplementary explanation of the feedback gain setting method will be given with reference to FIG.

  K1 and k2 in the equations (7) and (8) are feedback gains set from the lateral acceleration Yg with reference to the feedback gain map and each wheel driving force distribution map. In this feedback gain map, absolute values | k1 | and | k2 | of k1 and k2 that change in accordance with the lateral acceleration Yg are stored in the ROM of the controller 8 in advance. For example, as shown in FIG. The correction amount of the driving force front wheel distribution η is set to increase as the directional acceleration Yg increases. That is, the control sharing ratio of the driving force front wheel distribution η increases. In FIG. 14, feedback gains k3 and k4 used in equations (9) and (10) described later are also shown for convenience.

  Specifically, k1 to k4 are set by first determining | k1 | to | k4 | from the feedback gain map and the lateral acceleration Yg, and then distributing each wheel driving force at the current steering operation angle θ and the vehicle speed V. With reference to the map, the signs of k1 to k4 are determined so that the deviations (tYg−Yg) and (tβ−β) converge.

  According to this embodiment, when the turning amount is small, the turning amount is made to coincide with the target turning amount mainly by adjusting the left / right driving force difference, and the front / rear wheel driving force distribution adjustment amount is increased as the turning amount increases. It was set as the structure which enlarges. By adopting such a configuration, the turning amount can be made to match the target turning amount even if there are disturbances due to changes in the vehicle characteristics due to changes in the number of passengers and cargo, changes in the road surface μ, etc. It can be improved.

(Third embodiment)
FIG. 15 is a flowchart showing a third embodiment of the vehicle motion control apparatus according to the present invention.

  In the present embodiment, an attitude angle is to be realized by feedback control.

  Steps S10 to S50 are the same as those in the first embodiment.

  In step S83, the posture angle (side slip angle β) is estimated. As a specific estimation method, for example, as described in Japanese Patent Application Laid-Open No. 2000-52951 “Vehicle body slip angle estimation method and estimation device”, the speeds V2 to V4 of each wheel, the longitudinal acceleration Xg, the lateral acceleration Yg, the yaw rate Since it can be obtained by a known technique such as using a method for estimating the side slip angle β from γ, a description of the method for estimating the side slip angle β is omitted here.

  In step S84, a deviation Δβ between the target posture angle (target side slip angle tβ) and the estimated posture angle (side slip angle β) is calculated.

  In step S85, feedback gains k3 and k4 are set based on FIG. Specifically, as described above.

  In step S400, the left and right wheel driving force difference ΔT and the driving force front wheel distribution η are set according to equations (9) to (10).

ΔT = k3 × Δβ (9)
η = k4 × Δβ Formula (10)
And the drive torque Tm2-Tm4 of the motors 2-4 is set (step S90), and the motors 2-4 are controlled (step S100).

  According to this embodiment, there is provided means for detecting the current posture angle and means for adjusting the left and right wheel driving force difference and the front and rear wheel driving force distribution so that the detected posture angle matches the target posture angle. When the amount is small, the posture angle is made to coincide with the target posture angle mainly by adjusting the left and right driving force difference, and the adjustment amount of the front and rear wheel driving force distribution is increased as the turning amount increases. With this configuration, the posture angle can be matched to the target posture angle even when there are disturbances due to changes in vehicle characteristics due to changes in the number of passengers and cargo, and changes in the road surface μ, etc. It is possible to improve the performance.

(Fourth embodiment)
FIG. 16 is a flowchart showing a fourth embodiment of the vehicle motion control device according to the present invention.

  This embodiment is a combination of the map control of the first embodiment and the feedback control of the second embodiment.

  After performing the same processing as in the first embodiment up to steps S10 to S80, the deviation ΔYg between the target turning amount (target lateral acceleration tYg) and the actually detected turning amount (lateral acceleration Yg) is calculated. Then, the feedback gains k1 and k2 are set based on FIG. 14 (step S82).

  In step S86, the driving force front wheel distribution η and the left and right wheel driving force difference ΔT are corrected as in equations (11) to (12) so that the deviation ΔYg between the target lateral acceleration tYg and the lateral acceleration Yg is zero. To do.

ΔT = ΔT + k1 × ΔYg (11)
η = η + k2 × ΔYg (12)

  And the drive torque Tm2-Tm4 of the motors 2-4 is set (step S90), and the motors 2-4 are controlled (step S100).

  According to this embodiment, in addition to the effects of the first embodiment, even if there is a disturbance due to a change in vehicle characteristics due to a change in the number of passengers or cargo, a change in the road surface μ, etc., the turning amount is made to coincide with the target turning amount. Therefore, the turning performance can be improved.

(Fifth embodiment)
FIG. 17 is a flowchart showing a fifth embodiment of the vehicle motion control device according to the present invention.

  This embodiment is a combination of the map control of the first embodiment, the feedback control of the second embodiment, and the feedback control of the third embodiment.

  After performing the same processing as in the first embodiment up to steps S10 to S80, the deviation ΔYg between the target turning amount (target lateral acceleration tYg) and the actually detected turning amount (lateral acceleration Yg) is calculated. (Step S81), the posture angle (side slip angle β) is estimated (Step S83), and a deviation Δβ between the target posture angle (target side slip angle tβ) and the estimated posture angle (side slip angle β) is calculated (Step S84). ).

  In step S87, feedback gains k1, k2, k3, k4 are set based on FIG.

  In step S88, not only the deviation ΔYg of the target lateral acceleration tYg and the lateral acceleration Yg but also the deviation Δβ of the target side slip angle tβ and the side slip angle β are corrected as shown in equations (13) to (14). To do.

ΔT = ΔT + k1 × ΔYg + k3 × Δβ (13)
η = η + k2 × ΔYg + k4 × Δβ Equation (14).

  And the drive torque Tm2-Tm4 of the motors 2-4 is set (step S90), and the motors 2-4 are controlled (step S100).

  According to the present embodiment, in addition to the effects of the fourth embodiment, the posture angle is matched with the target posture angle even when there is a disturbance due to a change in vehicle characteristics due to a change in the number of passengers or cargo, a change in road surface μ, or the like. Therefore, the operability of the driver can be further improved.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

  The present invention is not limited to the vehicle shown in FIG. 3, for example, a vehicle in which each wheel is driven independently as shown in FIG. 18, a hybrid vehicle in which the driving source of the front wheels in FIG. The left and right drive distribution mechanism is added to the mechanical transmission means of a vehicle or the like having the function of freely controlling the steering angle of each wheel in the vehicle of FIGS. 3 and 18 or the conventional four-wheel drive vehicle using an engine as a drive source. It goes without saying that it can also be applied to what has been done.

  Further, various detection values such as a vehicle attitude angle (for example, a side slip angle β at the center of gravity of the vehicle) and a turning amount (for example, a lateral acceleration Yg of the vehicle) may be detected directly by a sensor or the like, or other sensors It may be detected (estimated) indirectly based on the detected value, and even in such a case, it is obvious that it is equivalent to the present invention.

It is a figure which shows lateral direction acceleration Yg with respect to right-and-left wheel driving force difference (DELTA) T and driving force front wheel distribution | distribution (eta) when the turning amount (lateral direction acceleration Yg) is small, and side slip angle (beta). It is a figure which shows lateral acceleration Yg and side slip angle (beta) with respect to right-and-left wheel driving force difference (DELTA) T and driving force front wheel distribution | distribution (eta) when turning amount (lateral acceleration Yg) is large. 1 is a block diagram showing a first embodiment of a mechanical configuration of an electric vehicle. It is a flowchart which shows 1st Embodiment of the vehicle motion control apparatus by this invention. It is a figure which shows an example of a request | requirement driving force map. It is a figure which shows an example of a request | requirement braking force map. It is a figure which shows an example of a target turning amount map. It is a figure which shows an example of a target attitude angle map. It is a figure which shows an example of each wheel driving force distribution map. It is a figure which shows an example of a right-and-left wheel driving force difference map. It is a flowchart for creating each wheel driving force distribution map and right and left wheel driving force difference map. It is a figure which shows the preparation method of each wheel driving force distribution map and the left-right wheel driving force difference map in the flowchart of FIG. It is a flowchart which shows 2nd Embodiment of the vehicle motion control apparatus by this invention. It is a setting map of a feedback gain. It is a flowchart which shows 3rd Embodiment of the vehicle motion control apparatus by this invention. It is a flowchart which shows 4th Embodiment of the vehicle motion control apparatus by this invention. It is a flowchart which shows 5th Embodiment of the vehicle motion control apparatus by this invention. It illustrates a vehicle in which each wheel is driven independently.

Explanation of symbols

Steps S10 and S20 Vehicle speed detecting means 25; Step S10 Steering angle detecting means 100; Step S10 Turning amount detecting means Steps S40 and S50 Target behavior determining means Steps S70 and S80 Driving force distribution determining means Step S81 Turning amount deviation calculation Means Step S83 Attitude angle detection means Step S84 Attitude angle deviation calculation means Steps S90, S100, S82, S85 to S88, S300, S400 Vehicle behavior control means

Claims (6)

A vehicle motion control device for controlling the motion of a vehicle capable of independently driving front and rear wheels and capable of independently driving left and right wheels for at least one of the front and rear wheels,
Steering angle detection means for detecting the steering operation angle;
Vehicle speed detection means for detecting the speed of the vehicle;
Target behavior determining means for determining a target turning amount and a target posture angle of the vehicle based on the steering wheel operation angle and the vehicle speed;
A turning amount detecting means for detecting a turning amount of the vehicle;
Wherein when the absolute value of the detected turning amount detected by the turning amount detection means is greater than the reference value, sets the left and right wheel driving force difference and the front-rear wheel driving force distribution based on the target turning amount and the target attitude angle, the When the absolute value of the detected turning amount is smaller than a reference value, driving force distribution determining means for setting a left and right wheel driving force difference based on the target turning amount;
Vehicle behavior control means for controlling vehicle behavior by controlling the left and right wheel driving force difference and front and rear wheel driving force distribution;
A vehicle motion control device comprising: Each wheel driving force distribution map storage means for storing each wheel driving force distribution map capable of setting the left and right wheel driving force difference and the front and rear wheel driving force distribution based on the target turning amount and the target posture angle;
Left and right wheel driving force difference map storage means for storing a left and right wheel driving force difference map capable of setting a left and right wheel driving force difference based on the target turning amount;
With
When the absolute value of the detected turning amount is larger than a reference value, the driving force distribution determining means sets the left and right wheel driving force difference and the front and rear wheel driving force distribution based on the wheel driving force distribution map, and detects the detection When the absolute value of the turning amount is smaller than the reference value, the left and right wheel driving force difference is set based on the left and right wheel driving force difference map.
The vehicle motion control device according to claim 1. A turning amount deviation calculating means for calculating a deviation between the target turning amount and the detected turning amount;
The vehicle behavior control means increases the control sharing ratio of front and rear wheel driving force distribution according to the increase in the detected turning amount, and controls the deviation between the target turning amount and the detected turning amount to be small.
The vehicle motion control device according to claim 1, wherein the vehicle motion control device is provided. Attitude angle detection means for detecting the attitude angle of the vehicle;
An attitude angle deviation calculating means for calculating a deviation between the detected attitude angle detected by the posture angle detecting means and the target attitude angle,
With
The vehicle behavior control means increases the control sharing ratio of front and rear wheel driving force distribution according to the increase in the detected turning amount, and controls the deviation between the target posture angle and the detected posture angle to be small.
The vehicle motion control device according to any one of claims 1 to 3, wherein A vehicle motion control device for controlling the motion of a vehicle capable of independently driving front and rear wheels and capable of independently driving left and right wheels for at least one of the front and rear wheels,
Steering angle detection means for detecting the steering operation angle;
Vehicle speed detection means for detecting the speed of the vehicle;
Target behavior determining means for determining a target turning amount of the vehicle based on the steering wheel operating angle and the vehicle speed;
A turning amount detecting means for detecting a turning amount of the vehicle;
A turning amount deviation calculating means for calculating a difference between the detected turning amount detected by the turning amount detecting means and the target turning amount,
And the vehicle behavior control means for controlling the vehicle behavior by controlling the left and right wheel driving force difference and the front-rear wheel power distribution,
With
The vehicle behavior control means increases the control sharing ratio of front and rear wheel driving force distribution according to the increase in the detected turning amount, and controls the deviation between the target turning amount and the detected turning amount to be small.
A vehicle motion control device. A vehicle motion control device for controlling the motion of a vehicle capable of independently driving front and rear wheels and capable of independently driving left and right wheels for at least one of the front and rear wheels,
Steering angle detection means for detecting the steering operation angle;
Vehicle speed detection means for detecting the speed of the vehicle;
Target behavior determining means for determining a target attitude angle of the vehicle based on the steering wheel operating angle and the vehicle speed;
A turning amount detecting means for detecting a turning amount of the vehicle;
Attitude angle detection means for detecting the attitude angle of the vehicle;
An attitude angle deviation calculating means for calculating a deviation between the detected attitude angle detected by the posture angle detecting means and the target attitude angle,
And the vehicle behavior control means for controlling the vehicle behavior by controlling the left and right wheel driving force difference and the front-rear wheel power distribution,
With
The vehicle behavior control means increases a control sharing ratio of front and rear wheel driving force distribution in accordance with an increase in the detected turning amount detected by the turning amount detection means, and a deviation between the target posture angle and the detected posture angle. Control to be smaller,
A vehicle motion control device.

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