JP7003555B2 - Motion control device for towing vehicles - Google Patents

Description

The present invention relates to a motion control device for a towing vehicle.

Patent Document 1 states that "a behavior control device that generates an anti-yaw moment for suppressing a sway state by braking force distribution control, and operates so that the vehicle is not decelerated when the anti-yaw moment is generated. For the purpose of "providing a behavior control device that can avoid the discomfort of the person and the influence on the following vehicle", "the yaw moment that suppresses the sway state by controlling the braking force distribution of each wheel when the sway state occurs" When it occurs, the driving force determined based on the deceleration amount of the vehicle due to the braking force generated in each wheel by the braking force distribution control is applied to the drive wheels of the vehicle. "

Further, in Patent Document 1, as a method of determining the braking force distribution of each wheel, "when an anti-yaw moment is generated in a tractor, an arbitrary method is used from the values of the vehicle's front-rear acceleration, pitch angle, etc." After detecting the position of the center of gravity of the tractor or the weight distribution in the front-rear direction, any method can be used based on the value (behavior state amount) of the sway vibration frequency band of the yaw rate γ of the tractor, the lateral acceleration Gy, or the vehicle body slip angular velocity β'. The anti-yaw moment Mc to be generated is determined, and the target value of the braking force Fmbi of each wheel that achieves the anti-yaw moment is determined. The braking force that generates the anti-yaw moment Mc is the front and rear wheels on one side. It may be added dispersedly in both of the above, or it may be added only by the non-driving wheel (front wheel). "

In addition, in Patent Document 1, "when an anti-yaw moment is generated to suppress a sway state and stabilize the vehicle, the vehicle is decelerated in order to apply braking force to the wheels of the tractor or trailer. The driver may feel uncomfortable and the following vehicle may be affected. Therefore, the driving force is applied to the driving wheels of the vehicle based on the deceleration amount generated by the braking force distribution control together with the generation of the anti-yaw moment, that is, the braking force distribution control. Is given, and the mitigation is achieved according to the degree of deceleration of the vehicle by the braking force distribution control. And the mitigation of the deceleration of the vehicle reduces the discomfort of the driver and the influence on the following vehicle. " Are listed.

In the device of Patent Document 1, it is necessary to detect the position of the center of gravity or the front-rear weight distribution in order to determine the target value of the braking force of each wheel in the swing suppression control that suppresses the sway behavior (also referred to as “swing”). Will be. It is said that the detection is performed based on the values of the vehicle's front-rear acceleration, pitch angle, and the like, but ensuring the detection accuracy can be a problem. Therefore, in determining the target braking force for each wheel, a method that is simpler and more robust is desired.

In addition, in the swing suppression control of Patent Document 1, not only the braking force but also the driving force is applied. However, in order to suppress the rocking of the vehicle, it is important to reduce the vehicle body speed in addition to generating the yaw moment. Therefore, it is necessary to appropriately adjust the braking force of each wheel according to the rocking state of the vehicle, taking into consideration the driving feeling of the driver.

Japanese Unexamined Patent Publication No. 2011-079470

An object of the present invention is to provide a vehicle motion control device that suppresses the sway behavior of a towing vehicle, in which a target braking force for each wheel can be stably determined.

The present invention relates to a towing vehicle including a tractor (VH) and a trailer (TR) towed by the tractor (VH). The motion control device for a towed vehicle according to the present invention uses a yaw rate sensor (YR) for detecting the actual yaw rate (Yr) of the tractor (VH) and a wheel speed (WH) for each wheel (WH) of the tractor (VH). The wheel speed sensor (VW) detected as Vw) and the braking force of each wheel (WH) are increased based on the actual yaw rate (Yr), and the trailer (TR) causes the periodic vehicle to be towed. It includes a controller (ECU) that executes damping control to damp the yaw motion.

In the traction vehicle motion control device according to the present invention, the controller (ECU) calculates the vehicle body speed (Vx) of the tractor (VH) based on the wheel speed (Vw), and converts the vehicle body speed (Vx) into the vehicle body speed (Vx). Based on this, the total braking force acting on the tractor (VH) is calculated as the total braking force (Fv), and the total braking force (Fv) is calculated for each wheel (WH) based on the actual yaw rate (Yr). It is configured to be distributed to the braking force (Fw).

The total braking force Fv (target value) is calculated based on the vehicle body speed Vx, and this is distributed to the braking force Fw ** of each wheel WH ** based on the actual yaw rate Yr. For example, based on the actual yaw rate Yr, the turning outer wheel and the turning inner wheel are discriminated in the turning direction of the tactile VH. The total braking force Fv is distributed to the left and right wheels so that the braking force of the turning outer wheel becomes larger than the braking force of the turning inner wheel.

The larger the vehicle body speed Vx, the more likely the rocking occurs, and the smaller the vehicle body speed Vx, the less likely it is to occur. According to the above configuration, there is no excess or deficiency in the braking force acting on the entire vehicle, and stable swing suppression control can be executed at all times. Further, since the braking force of the turning outer wheel is made larger than the braking force of the turning inner wheel, a yaw moment that cancels the swing can be effectively formed.

In the motion control device for a towing vehicle according to the present invention, the controller (ECU) calculates a yaw index (Jp) representing the degree of yaw motion based on the actual yaw rate (Yr), and the yaw index (Jp). ) Is larger, the total braking force (Fv) is modified to be larger. According to the above configuration, the degree of rocking is taken into consideration in determining the total braking force Fv. Then, as the degree of rocking is larger, the total braking force Fv is increased and adjusted so that a larger vehicle deceleration can be obtained. Thereby, the swing can be surely suppressed.

It is an overall configuration diagram of the vehicle equipped with the motion control device CS of the towing vehicle according to the present invention. It is a control flow diagram for demonstrating the outline of the arithmetic processing in a controller ECU. It is a time series diagram for demonstrating the operation of a peak value Yp, and the start and end of control. It is a functional block diagram for demonstrating the arithmetic processing of each wheel braking force control Fw.

<Symbols of constituent members, subscripts at the end of symbols, and moving directions>
An embodiment of the motion control device CS for a towing vehicle according to the present invention will be described with reference to the drawings. In the following description, components, arithmetic processing, signals, characteristics, and values having the same symbol, such as "ECU", have the same function. Further, the subscript "**" added to the end of each symbol indicates which of the four wheels on the front, back, left and right of the tractor VH, or the two wheels on the left and right of the trailer TR. Specifically, in the tractor VH, "fl" corresponds to the left front wheel, "fr" corresponds to the right front wheel, "rl" corresponds to the left rear wheel, and "rr" corresponds to the right rear wheel, respectively. is doing. Further, in the trailer TR, "tl" corresponds to the left wheel and "tr" corresponds to the right wheel.

“F *” represents the left and right front wheels of the tractor VH, “r *” represents the left and right rear wheels of the tractor VH, and “t *” represents the left and right wheels of the trailer TR. Further, the subscript "**" may be omitted. When "**" is omitted, the symbol represents a general term for the corresponding member or the like. For example, the wheel speed sensor VWf * represents the wheel speed sensors VWfl and VWfr for the front wheels, and the wheel speed sensor VWr * represents the wheel speed sensors VWrl and VWrr for the rear wheels. The wheel speed sensor VW ** (also referred to as “VW” when the subscript “**” is omitted) comprehensively indicates the four wheel speed sensors VWfl, VWfr, VWrr, and VWrr of the tractor VH.

<Overall configuration of motion control device for towing vehicle according to the present invention>
The motion control device CS according to the present invention will be described with reference to the overall configuration diagram of FIG. The vehicle is a so-called towing vehicle composed of a tractor VH and a trailer TR towed by the tractor VH.

The traction vehicle (particularly, the tractor VH) equipped with the motion control device CS includes a braking operation member BP, a braking operation amount sensor BA, a steering operation member SW, a steering angle sensor SA, a wheel speed sensor VW **, an yaw rate sensor YR, and front and rear. It is provided with an acceleration sensor GX, a lateral acceleration sensor GY, a braking hydraulic pressure sensor PW **, a braking actuator (simply also referred to as “activator”) BR, and a controller ECU. Further, the tractor VH is provided with a power source PR and a transmission TN in order to accelerate the towing vehicle and travel at a constant speed.

The braking operation member (for example, the brake pedal) BP is a member operated by the driver to decelerate the vehicle. By operating the braking operation member BP, the braking torque for the wheel WH ** (also simply referred to as “WH”) is adjusted, and the braking force F ** is generated on the wheel WH **.

A braking operation amount sensor (simply also referred to as "operation amount sensor") BA is provided so as to detect the operation amount Ba of the braking operation member (brake pedal) BP by the driver. Specifically, as the braking operation amount sensor BA, a master cylinder hydraulic pressure sensor that detects the hydraulic pressure (master cylinder hydraulic pressure) in the master cylinder CM, an operation displacement sensor that detects the operation displacement of the braking operation member BP, and At least one of the operation force sensors for detecting the operation force of the braking operation member BP is adopted. That is, the braking operation amount Ba is determined based on at least one of the master cylinder hydraulic pressure, the braking operation displacement, and the braking operation force.

The steering operation member (for example, the steering wheel) SW is a member operated by the driver to turn the vehicle. By operating the steering operation member SW, a steering angle Sa is applied to the steering wheel (for example, the front wheel WHf *), a lateral force is generated on the wheel WH **, and the vehicle is turned.

A steering angle sensor SA is provided so as to detect the rotation angle (steering angle) Sa of the steering operation member SW. For example, the steering angle Sa is a rotation angle from the steering neutral position "Sa = 0" corresponding to the straight running of the vehicle. In the steering angle Sa, the left turning direction is represented by a plus sign and the right turning direction is represented by a minus sign.

Further, although not shown, an acceleration operating member (for example, an accelerator pedal) is provided, which is operated by the driver to adjust the output of the power source PR of the vehicle to accelerate the vehicle. Further, the transmission TN is provided with a shift operation member (for example, a shift lever) for performing a shift operation. Then, an acceleration operation amount sensor for detecting the operation amount of the acceleration operation member and a shift position sensor for detecting the shift position of the speed change operation member are provided.

The power source PR (for example, an internal combustion engine) is provided with a throttle sensor TH for detecting the throttle opening Th, an injection amount sensor FI for detecting the fuel injection amount Fi, and a rotation speed sensor NE for detecting the drive rotation speed Ne. Will be. Further, the transmission TN is provided with a gear position sensor GR for detecting the gear ratio (gear position) Gr. Throttle opening Th, fuel injection amount Fi, power source drive rotation speed Ne, and gear position Gr are used to calculate the output (drive torque) of the vehicle power train (power source PR, transmission TN). Will be adopted by. When the power source PR is a driving electric motor, the amount of electricity supplied to the power source PR (for example, a current value) can be detected. The signal obtained by each sensor is input to the controller ECU via the communication bus BS.

The tractor VH is provided with a wheel speed sensor VW ** that detects the wheel speed Vw **, which is the rotational speed of the wheel WH **. The totactor VH is provided with a vehicle behavior sensor that detects the motion state of the vehicle. Specifically, the yaw rate sensor YR that detects the actual yaw rate (yaw angle speed) Yr of the vehicle, the front-back acceleration sensor GX that detects the acceleration (front-back acceleration) Gx in the front-rear direction of the vehicle, and the acceleration in the lateral direction of the vehicle ( Lateral acceleration) A lateral acceleration sensor GY that detects Gy is provided.

Each wheel WH ** of the vehicle is provided with a brake caliper CP **, a wheel cylinder CW **, a rotating member KT **, and a friction member MS. Specifically, a rotating member (for example, a brake disc, also simply referred to as "KT") KT ** is fixed to the wheel WH, and a brake caliper CP ** (simply "CP") is interposed so as to sandwich the rotating member KT **. ”) Is placed. The brake caliper (simply also referred to as "caliper") CP is provided with a wheel cylinder CW ** (simply also referred to as "CW"). By adjusting (increasing or decreasing) the hydraulic pressure in the wheel cylinder CW, the piston in the wheel cylinder CW is moved (advanced or retracted) with respect to the rotating member KT. By this movement of the piston, the friction member (for example, the brake pad) MS is pressed against the rotating member KT, and a pressing force is generated. The rotating member KT and the wheel WH are fixed so as to rotate integrally. Therefore, the braking torque (resulting in the braking force F) is generated in the wheel WH due to the frictional force generated by the pressing force. The tactor VH is provided with a braking fluid pressure sensor PW ** so as to detect the braking hydraulic pressure Pw ** of the wheel cylinder CW **.

The braking actuator (also simply referred to as “actuator”) BR is connected to the wheel cylinder CW ** via the braking pipe HK **. The actuator BR is composed of a master cylinder CM and a hydraulic pressure unit HU. For example, the hydraulic pressure unit HU includes a plurality of solenoid valves, a fluid pump, an electric motor, and the like.

When braking control including rocking suppression control (damping control) is not executed, the actuator BR (particularly, the master cylinder CM) causes the braking fluid pressure Pw ** according to the operation of the braking operation member BP by the driver on each wheel. It is supplied to each of the wheel cylinders CW ** of WH **. Then, a braking torque corresponding to the operation amount Ba of the braking operation member (brake pedal) BP is applied to each wheel WH. As a result, braking force F ** is generated on the wheel WH **.

When performing braking control such as anti-skid control, traction control, vehicle stabilization control (including rocking suppression control), etc., the actuator BR (particularly, the hydraulic pressure unit HU) is independent of the operation of the braking operation member BP. Therefore, the braking fluid pressure Pw is controlled for each wheel cylinder CW. That is, the braking force F of each wheel WH is adjusted independently.

The vehicle is provided with an actuator BR and an electronic control unit ECU (microcomputer) electrically connected to the above-mentioned various sensors (YR or the like). The electronic control unit (also referred to as "controller") ECU is composed of a plurality of independent controller ECUs (ECB, ECP, etc.) connected by a communication bus BS. Each controller (ECB, etc.) in the controller ECU executes a dedicated control program. The signals of various sensors (sensor values) and the signals calculated in each controller (internally calculated values) are shared via the communication bus BS.

For example, the braking controller ECB is a controller for the actuator BR. The braking operation amount Ba, steering angle Sa, wheel speed Vw, yaw rate Yr, front-rear acceleration Gx, lateral acceleration Gy, and braking fluid pressure Pw are input to the braking controller ECB. The controller ECB instructs the hydraulic unit HU to drive signal Hu to execute the above braking control based on the programmed control algorithm. By this drive signal Hu, the electric motor and the solenoid valve in the hydraulic pressure unit HU are driven, and braking control is realized.

The drive controller ECP is a controller for the power source PR. Throttle opening Th, fuel injection amount Fi, power source drive rotation speed Ne, and gear position Gr are input to the drive controller ECP. Further, the drive controller ECP receives an instruction signal from the braking controller ECB via the communication bus BS. In the drive controller ECP, the output of the power source PR is reduced when the traction control and the vehicle stabilization control are executed based on the instruction signal.

<Operation processing of swing suppression control>
The arithmetic processing of the swing suppression control (damping control) will be described with reference to the control flow diagram of FIG. The "swing suppression control" suppresses (damps) the periodic swing (sway behavior) of the towing vehicle caused by the trailer TR, and is also called "damping control" or "trail way control". To. The swing suppression control process is programmed in the electronic control unit ECU (for example, the braking controller ECB).

In step S110, signals (Sa, Vw, Yr, Gy, etc.) from the steering angle sensor SA, wheel speed sensor VW, yaw rate sensor YR, lateral acceleration sensor GY, etc. are read.

In step S120, the yaw angular acceleration dY is calculated based on the actual yaw rate Yr. Specifically, the actual yaw rate Yr is time-differentiated, and the yaw angular acceleration dY is calculated. The yaw angular acceleration dY is the amount of change in the actual yaw rate Yr per unit time.

In step S130, the yaw rate deviation hY is calculated based on the steering angle Sa, the wheel speed Vw, and the yaw rate Yr. First, in step S130, the traveling speed (vehicle body speed) Vx of the vehicle is calculated based on the wheel speed Vw of each wheel WH detected by the wheel speed sensor VW. For example, at the time of braking (when the braking operation member BP is operated), the vehicle body speed Vx is calculated based on the fastest of the four wheel speeds Vw. Further, during non-braking (when the braking operation member BP is not operated), the vehicle body speed Vx is calculated based on the slowest of the four wheel speeds Vw.

Then, the normative yaw rate Yt is calculated based on the steering angle Sa and the vehicle body speed Vx. The normative yaw rate Yt is a state quantity that expresses a reference state in which the wheel WH grips the traveling road surface and the vehicle does not have excessive understeer or oversteer behavior. Based on the normative yaw rate Yt and the actual yaw rate Yr, the normative yaw rate Yt (normative value) is subtracted from the actual yaw rate Yr (detection value), and the yaw rate deviation hY (= Yr−Yt) is calculated.

In step S140, the yaw rate peak value Yp is calculated based on the actual yaw rate Yr (detection value). The minimum value Yc and the maximum value Yo for the yaw rate Yr are determined based on the change of the yaw rate Yr in the time series. The absolute value of the minimum value Yc and the maximum value Yo is defined as the yaw rate peak value Yp.

In step S150, the yaw index Jp is calculated based on at least one of the yaw angular acceleration dY, the yaw deviation hY, and the yaw peak value Yp. The yaw index Jp is a state quantity representing the magnitude (degree) of the periodic yaw motion (that is, rocking, sway behavior) of the vehicle, and is also referred to as “swing index Jp”. For example, as the yaw index Jp, the peak value of the yaw angular acceleration dY (yaw angular acceleration peak value) dYp is adopted. That is, the yaw angular acceleration dY is stored in time series (for each calculation cycle), and the stored peak value of the yaw angular acceleration dY (the absolute value of the maximum value Do and the minimum value Dc in one cycle) is the yaw angular acceleration peak. Determined as the value dYp.

Further, the peak value (yaw rate deviation peak value) hYp of the yaw deviation hY may be determined as the yaw index (oscillation index) Jp. Similar to the yaw angular acceleration peak value dYp, the yaw rate deviation hY is stored in each calculation cycle, and the absolute values of the maximum value Ho and the minimum value Hc in one cycle are determined as the yaw rate deviation peak value hYp.

Further, the yaw rate peak value Yp (extreme value Yc, absolute value of Yo) calculated in step S140 can be directly determined as the yaw index (oscillation index) Jp. In this case, in the vibrating yaw rate (oscillation) Yr, the yaw index Jp is updated every cycle of the yaw rate Yr. The yaw index Jp may be calculated by combining two or more of the yaw angular acceleration peak value dYp, the yaw rate deviation peak value hYp, and the yaw rate peak value Yp.

In step S160, it is determined whether or not the swing suppression control is being executed. If the swing suppression control is being executed, step S160 is affirmed, and the process proceeds to step S180. On the other hand, if the swing suppression control is not executed, step S160 is denied and the process proceeds to step S170.

In step S170, "whether or not the start condition of the swing suppression control is satisfied" is determined based on the yaw rate peak value Yp. If step S170 is affirmed, the process proceeds to step S190, and swing suppression control is started. On the other hand, if step S170 is denied, the process returns to step S110.

In step S180, "whether or not the end condition of the swing suppression control is satisfied" is determined based on the yaw rate peak value Yp. If step S180 is denied, processing proceeds to step S190, and rocking suppression control is continued. On the other hand, if step S180 is affirmed, the swing suppression control is terminated and the process is returned to step S110. Details of the start / end determination of the swing suppression control in steps S170 and S180 will be described later.

In step S190, step S200, and step S210, swing suppression control is executed. In step S190, the total braking force Fv is calculated based on the vehicle body speed Vx, the braking operation amount Ba, and the yaw index Jp. The total braking force Fv is a target value of the braking force F ** applied to the entire vehicle. In step S200, the target value Fw ** of the braking force of each wheel WH ** is calculated based on the total braking force Fv and the yaw index Jp. Then, in step S210, the braking torque applied to each wheel WH ** is servo-controlled based on each wheel braking force Fw ** (target value). Detailed processing from step S190 to step S210 will be described later.

<Calculation of yaw rate peak value Yp and determination of start and end of control>
The calculation of the yaw rate peak value Yp and the control start / end determination will be described with reference to the time-series diagram of FIG.

The maximum value Yo and the minimum value Yc of the actual yaw rate Yr are calculated based on the time-series data of the yaw rate Yr after the filtering. Here, the maximum value Yo and the minimum value Yc are referred to as “peak value Yp”. Determined based on comparison with.

When the yaw rate Yr is increasing, at the time when "Yr (n)> Yr (n-1)" is switched to "Yr (n) <Yr (n-1)" (calculation cycle). The yaw rate Yr (n-1) is stored as the maximum value Yo. Here, "n" represents a calculation period. Similar to the increase of the yaw rate Yr, when the yaw rate Yr is decreasing, "Yr (n) <Yr (n-1)" is switched to "Yr (n)> Yr (n-1)". At the time point (calculation cycle), the yaw rate Yr (n-1) is stored as the minimum value Yc. Then, the amplitude Ay of the fluctuation is calculated based on the yaw rate peak value Yp (that is, the extreme values Yo and Yc). Specifically, the deviation (absolute value) Ay between the maximum value Yo and the minimum value Yc is calculated.

The execution start of the swing suppression control is determined based on the yaw rate amplitude Ay, the threshold amplitude ax, and the threshold number nx. When the yaw rate amplitude Ay is equal to or greater than the threshold amplitude ax (Ay ≧ ax), “1 (times)” is added to the number of swings Ny. However, when the amplitude Ay is less than the threshold amplitude ax (Ay <ax), "1" is not added to the number of swings Ny and is left as it is. That is, the number of times (number of swings) Ny that the condition of "Ay ≧ ax" is satisfied is calculated. When the number of swings Ny reaches the threshold number nx (calculation cycle), the start of the swing suppression control is determined. Here, the threshold amplitude ax is a threshold value for determining the amplitude of the swing, and is a preset constant. Further, the threshold number nx is a threshold value for determining the number of occurrences of fluctuation Ny, and is a preset constant. By setting the threshold number nx, the influence of noise and the like can be avoided.

The end of the swing suppression control is determined based on the number of swings Ny. Specifically, when the time during which the state in which the number of swings Ny is not increased (the time during which the condition of "Ay <ax" continues to be satisfied) becomes a predetermined time ts or more (calculation cycle), the swing is performed. The motion suppression control is terminated. Further, the swing suppression control may be terminated when the vehicle body speed Vx becomes less than the predetermined speed vs. Here, the predetermined time ts and the predetermined speed vs. are preset threshold values (predetermined values) for end determination.

For example, the case where the threshold number nx is set to "3" will be described. The towing vehicle begins to swing, and the peak value (maximum value, minimum value) Yp of the yaw rate Yr is calculated. The maximum value Yo [0] is determined and stored at the time point t0 after the maximum value Yo [0] of the yaw rate Yr is actually generated. After that, the minimum value Yc [1] is calculated at the time point t1 after the minimum value Yc [1] of the yaw rate Yr is actually generated. At time point t1, the amplitude Ay [1] is calculated as the absolute value of "Yc [1] -Yo [0]". At time point t1, the amplitude Ay [1] is less than the threshold amplitude ax, so the number of swings Ny remains "0". The process is sequentially continued.

At time point t5, the minimum value Yc [5] in the current calculation cycle and the stored maximum value Yo [4] are compared, and the amplitude Ay [5] (= Ay [5] -Ay [4]). Is calculated. At the time point t5, since the amplitude Ay [5] is equal to or greater than the threshold amplitude ax, the number of swings Ny is increased by “1” from “0”. However, since the number of swings Ny is less than the number of thresholds nx (= 3), the swing suppression control is not started.

At the time point t6, the amplitude Ay [6] (= Ay [6] -Ay [5]) is calculated, and in order to satisfy "Ay [6] ≧ ax", the number of swings Ny increases to "2". Will be done. Further, at the time point t7, the amplitude Ay [7] (= Ay [7] -Ay [6]) is calculated and "Ay [7] ≧ ax" is satisfied, so that the number of swings Ny is "3". Will be increased to. At the time point t7, the number of swings Ny reaches the threshold number nx, so that the execution of the swing suppression control is started. At this point, the control flag FL representing the execution state of the swing suppression control is changed from "0 (non-execution)" to "1 (execution)".

At the time point t8, the amplitude Ay [8] is calculated and “Ay [8] ≧ ax” is satisfied. Therefore, the number of swings Ny increases to “4” while the swing suppression control is being executed. Will be done. When the number of swings Ny is sequentially increased, the execution of the swing suppression control is continued, and the control flag FL is maintained at "1 (execution)".

By executing the swing suppression control, the vehicle body speed Vx is reduced, and when the swing (sway behavior) of the towing vehicle converges, the amplitude Ay of the yaw rate Yr becomes smaller. For example, at the time point t13, the amplitude Ay [13] is calculated, but since "Ay [13] <ax", the number of swings Ny is not increased. Then, at the time point t16 in which this state is continued for a predetermined time ts, the swing suppression control is terminated and the control flag FL is switched from "1" to "0". If the condition of "Vx <vs" is satisfied before the time point t16, the execution of the swing suppression control may be terminated at that time point.

As soon as "Ay ≧ ax" is satisfied, the swing suppression control is not started, and the start of the swing suppression control is determined based on the number of times Ny when "Ay ≧ ax" is satisfied. Therefore, the influence of noise is compensated, and reliable execution of swing suppression control can be achieved.

In the above, the process of starting and ending the swing suppression control based on the actual peak value Yp of the yaw rate Yr (absolute value of the maximum value Yo and the minimum value Yc) has been described. As another processing example, instead of the actual yaw rate Yr, a value "Gy / Vx" obtained by dividing the actual lateral acceleration Gy by the vehicle body speed Vx can be adopted. Here, since the state quantity "Gy / Vx" is a physical quantity having the same dimension as the yaw rate Yr, it is called "calculated yaw rate Ye". In the same manner as described above, the maximum value Eo of the calculated yaw rate Ye and the minimum value Ec of the calculated yaw rate Ye are calculated based on the time-series data of the calculated yaw rate Ye after the filtering process. Then, the deviation between the maximum value Eo and the minimum value Ec is calculated as the amplitude Ae of the calculated yaw rate Ye, and is compared with the threshold amplitude ax. When the amplitude Ae (absolute value) is equal to or greater than the threshold amplitude ax (Ae ≧ ax), the number of swings Ny is increased by “1 (times)”. When the number of swings Ny becomes equal to or greater than the threshold number nx (when "Ny = nx" is established), the swing suppression control is started.

The steering angle Sa may be referred to for the integration of the number of swings Ny. Specifically, as a condition for increasing the number of swings Ny, "the direction of the steering angle Sa and the direction of the actual yaw rate Yr (or the calculated yaw rate Ye, that is, the actual lateral acceleration Gy) do not match. That "can be added. In other words, even if the condition of "Ay ≧ ax (or" Ae ≧ ax) "is satisfied, if the steering angle Sa and the actual yaw rate Yr (or the calculated yaw rate Ye) are in the same direction, The number of swings Ny is not increased. Depending on the condition, the swing caused by the steering angle Sa can be distinguished. The "direction" is the direction in which the vehicle turns (right direction or left direction), and is represented by a code of a state quantity (Sa, Yr, Gy, etc.).

In order to reduce the influence of the steering angle Sa, the yaw rate deviation hY may be adopted instead of the actual yaw rate Yr and the calculated yaw rate Ye. The normative yaw rate Yt is calculated based on the steering angle Sa and the vehicle body speed Vx. The difference between the actual yaw rate Yr and the normative yaw rate Yt is determined as the yaw rate deviation hY (ie, "hY = Yr-Yt"). Similarly to the above, the maximum value Ho and the minimum value Hc are calculated based on the time series data of the yaw rate deviation hY. In the yaw rate deviation hY, the difference between the maximum value Ho and the minimum value Hc is calculated as the amplitude Ah and contrasted with the threshold amplitude ax. When the amplitude Ah (absolute value) is equal to or greater than the threshold amplitude ax (Ah ≧ ax), the number of swings Ny is increased by “1”, and the number of swings Ny becomes equal to or higher than the threshold number nx. When this happens (when "Ny = nx" is established), the swing suppression control can be started.

The start and / or end of the swing suppression control can be determined based on the time series data of a plurality of state quantities (Yr, etc.). Therefore, the start and end of the swing suppression control are based on at least one of the actual yaw rate (detected yaw rate) Yr, the calculated yaw rate Ye (= Gy / Vx), and the yaw rate deviation hY (= Yr-Yt). Can be determined. That is, at least one of the three amplitudes Ay, Ae, and Ah is calculated, and the number of swings Ny is calculated by comparing with the threshold amplitude ax. Then, the number of swings Ny is compared with the number of thresholds nx, and the start of the swing suppression control is determined. Further, the swing suppression control ends when any one of "the time during which the number of swings Ny is not increased is ts or more for a predetermined time" and "the vehicle body speed Vx is less than the predetermined speed vs" is satisfied. Will be done.

<Calculation processing of braking force control for each wheel>
The processing of braking force control in each wheel WH ** in steps S190 and S210 will be described with reference to the functional block diagram of FIG.

As described above, the components, arithmetic processing, signals, characteristics, and values with the same symbol have the same function. Further, the subscript "**" attached to the end of each symbol indicates which of the four wheels on the front, back, left and right of the tractor VH, or the two wheels on the left and right of the trailer TR. Specifically, in the tractor VH, "fl" corresponds to the left front wheel, "fr" corresponds to the right front wheel, "rl" corresponds to the left rear wheel, and "rr" corresponds to the right rear wheel, respectively. is doing. In the trailer TR, "tl" corresponds to the left wheel and "tr" corresponds to the right wheel. Further, the subscript "**" may be omitted. Further, "f *" represents the left and right front wheels of the tractor VH, "r *" represents the left and right rear wheels of the tractor VH, and "t *" represents the left and right wheels of the trailer TR.

In the vehicle body speed calculation block VX included in step S130, the vehicle body speed Vx is calculated based on the wheel speed Vw detected by the wheel speed sensor VW of each wheel WH. For example, when the vehicle is not braking (including acceleration), the vehicle body speed Vx is determined based on the slowest wheel speed Vw. Further, when the vehicle is braked, the vehicle body speed Vx is determined based on the fastest wheel speed Vw.

In the yaw index calculation block JP included in step S150, the yaw index Jp is calculated based on the yaw rate Yr and the like. The yaw index Jp is an index expressing the degree (magnitude) of swing (periodic yaw movement). In the yaw index calculation block JP, the yaw peak value Yp calculated based on the yaw rate Yr is determined as the yaw index Jp. Here, the yaw rate peak value Yp is an absolute value of the maximum value Yo and the minimum value Yc in one cycle of the fluctuation of the actual yaw rate Yr. Therefore, a large yaw rate peak value Yp indicates a large degree of fluctuation.

Instead of the actual yaw rate Yr peak value Yp, the value obtained by dividing the actual lateral acceleration Gy by the vehicle body speed Vx (calculated yaw rate) Ye (= Gy / Vx) peak value Ep (minimum value Ec, maximum value Eo) Absolute value) can be adopted as the yaw index Jp. The calculated yaw rate Ye is based on the state quantity equivalent to the yaw rate Yr.

Instead of the actual yaw rate Yr and / or the calculated yaw rate Ye, the yaw index Jp can be calculated based on the yaw rate deviation hY. That is, in the yaw rate deviation hY, the maximum value Ho and the absolute value hYp of the minimum value Hc are determined as the yaw index Jp. By adopting the yaw rate deviation hY in the calculation of the yaw index Jp, the influence of the steering angle Sa can be suppressed.

The peak value of the yaw angular acceleration dY (yaw angular acceleration peak value) dYp can be adopted as the yaw index Jp. That is, in the fluctuation of the yaw angular acceleration dY (differential value of the yaw rate Yr), the maximum value Do and the absolute value (yaw angular acceleration peak value) dYp of the minimum value Dc can be determined as the yaw index Jp.

In the above, the peak values Yp, Ep, hYp, and dYp in various state quantities were determined as the yaw index Jp. Instead of this, the maximum values Ym, Em, hYm, and dYm of the actual yaw rate Yr, the calculated yaw rate Ye, the yaw rate deviation hY, and the yaw angular acceleration dY can be adopted as the yaw index Jp. The peak values Yp, Ep, hYp, and dYp are the peak values in each cycle of the fluctuation, but the maximum values Ym, Em, hYm, and dYm are the largest of the peak values Yp, Ep, hYp, and dYp. Is. Therefore, the maximum values Ym, Em, hYm, and dYm are determined based on the peak values Yp, Ep, hYp, and dYp. However, the peak values Yp, Ep, hYp, and dYp represent the degree of fluctuation in each cycle in the fluctuation that changes from moment to moment. Therefore, it is preferable to adopt peak values Yp, Ep, hYp, and dYp as the state quantity (yaw index) Jp representing the periodic yaw motion of the towing vehicle.

Each wheel braking force control in step S190 or step S210 is performed by the indicated deceleration calculation block GQ, the required deceleration calculation block GV, the total braking force calculation block FV, the left-right distribution ratio calculation block HA, and the front-rear distribution ratio calculation block HB. , Each wheel braking force calculation block FW, and each wheel servo processing block SV.

In the indicated deceleration calculation block GQ, the indicated deceleration Gq is calculated based on the braking operation amount Ba and the calculation map Zgq. The indicated deceleration Gq corresponds to the front-rear acceleration of the vehicle corresponding to the braking operation of the driver. Specifically, when the braking operation amount Ba is less than the predetermined value ba0 based on the calculation map Zgq, the indicated deceleration Gq is set to "0". When the braking operation amount Ba is greater than or equal to the value ba0 and less than the value ba1 (predetermined value), the indicated deceleration Gq is calculated to increase as the braking operation amount Ba increases. When the braking operation amount Ba is equal to or greater than the value ba1, the indicated deceleration Gq is calculated to the value gq1 (predetermined value). Here, the predetermined value ba0 is a preset constant corresponding to the play of the braking operation member BP.

In the required deceleration calculation block GV, the required deceleration Gv is calculated based on the vehicle body speed Vx and the calculation map Zgv. The required deceleration Gv is the deceleration (target value) of the vehicle generated by the rocking suppression control, which is necessary to attenuate the periodic rocking of the towing vehicle. Specifically, when the vehicle body speed Vx is less than the value vs. based on the calculation map Zgv, the required deceleration Gv is not calculated (or remains "0"), and the swing suppression control is not executed. .. However, when the vehicle body speed Vx is equal to or greater than the value vs and less than the value vx1, the required deceleration Gv is calculated to the value gv1. When the vehicle body speed Vx is equal to or greater than the value vx1 and less than the value vx2, the required deceleration Gv is calculated to increase as the vehicle body speed Vx increases. Then, when the vehicle body speed Vx is a value vx2 or more, the required deceleration Gv is calculated to the value gv2. That is, in the required deceleration calculation block GV, the required deceleration Gv is calculated to be larger as the vehicle body speed Vx is larger, and the required deceleration Gv is smaller as the vehicle body speed Vx is smaller, based on the calculation map Zgv. It is calculated. Here, the value vs, the value vx1, the value vx2, the value gv1, and the value gv2 are predetermined values set in advance for the calculation map Zgv.

The indicated deceleration Gq and the required deceleration Gv are added to calculate the target deceleration Gt. The target deceleration Gt is the final target value for vehicle deceleration in consideration of the driver's braking operation. In the non-braking time when the braking operation member BP is not operated, since "Gq = 0", it is determined as "Gt = Gv". The target deceleration Gt is input to the total braking force calculation block FV.

In the total braking force calculation block FV (corresponding to step S190), the total braking force Fv (target value) is calculated based on the target deceleration Gt. Specifically, in the total braking force calculation block FV, the target deceleration Gt is multiplied by the vehicle mass Mv to determine the total braking force Fv (= Mv · Gt). The total braking force Fv is a target value of the total (total) braking force acting on the entire vehicle. Here, a preset predetermined value can be adopted as the vehicle mass Mv. Further, when the vehicle (tactor VH + trailer TR) is traveling straight, the power source PR is based on at least one of the throttle opening Th, the power source rotation speed Ne, and the fuel injection amount Fi. The output is estimated, and the mass Mv can be calculated based on the front-rear acceleration Gx (or the calculated deceleration Ge which is a differential value of the vehicle body speed Vx) generated at this time.

In the total braking force calculation block FV, the total braking force Fv can be adjusted (corrected) based on the yaw index Jp. The yaw index Jp is a state quantity indicating the degree (magnitude) of the swing, and the larger the yaw index Jp, the larger the total braking force Fv (target value) (or the yaw index Jp is adjusted). The smaller the value, the smaller the total braking force Fv). That is, the correction is made so that the target total braking force Fv increases as the yaw index Jp increases. The total braking force Fv is input to each wheel braking force calculation block FW.

As described above, in the total braking force calculation block FV, the total braking force Fv is determined based on the vehicle body speed Vx. The larger the vehicle body speed Vx, the more likely the rocking occurs, and the smaller the vehicle body speed Vx, the less likely it is to occur. Therefore, the total braking force Fv is determined based on the vehicle body speed Vx, and is allocated (allocated) to the target braking force Fw ** of each wheel WH ** in each wheel braking force calculation block FW described later. .. Therefore, there is no excess or deficiency in the braking force acting on the entire vehicle, and stable swing suppression control is achieved.

In addition, in the total braking force calculation block FV, the yaw index Jp is taken into consideration, and the total braking force Fv (target value) determined based on the vehicle body speed Vx is corrected. The yaw index Jp is a state quantity indicating the degree of swing, and adjustment is made so that the larger the yaw index Jp, the larger the total braking force Fv. Thereby, the swing can be surely suppressed.

In the left-right distribution ratio calculation block HA, the left-right distribution ratio Ha is calculated based on the yaw index Jp and the calculation map Zha. The left-right distribution ratio Ha is between the left and right wheels for allocating the total braking force Fv for achieving the target deceleration Gt to the braking force of the left and right wheels (that is, between the wheels located outside and inside with respect to the turning direction). Is the distribution ratio of. Here, the turning outer wheel and the turning inner wheel are identified based on the actual yaw rate Yr (particularly, the symbol thereof). Specifically, when the turning direction of the vehicle (particularly, the totactor VH) is the left direction (that is, turning left) and the actual yaw rate Yr is a plus sign, the right front wheel WHfr and the right rear wheel WHrr It is identified as a turning outer wheel, and the left front wheel WHfl and the left rear wheel WHrl are identified as turning inner wheels. On the other hand, when the turning direction of the vehicle (Totakuta VH) is the right direction (right turning) and the actual yaw rate Yr is a minus sign, the left front wheel WHfl and the left rear wheel WHrl are the turning outer wheels. The right front wheel WHfr and the right rear wheel WHrr are the turning inner wheels. The left-right distribution ratio Ha is a ratio to the front and rear wheels on the outside of the turn. Therefore, the ratio to the front and rear wheels on the inside of the turn is "1-Ha".

The left-right distribution ratio (ratio of front and rear wheels on the outside of turning) Ha is calculated to a value ha1 (a value larger than "0.5") when the yaw index Jp is less than the value ja1 based on the calculation map Zha. When the yaw index Jp is greater than or equal to the value ja1 and less than the value ja2, the left-right distribution ratio Ha is calculated to increase as the yaw index Jp increases. Then, when the yaw index Jp is a value ja2 or more, the left-right distribution ratio Ha is calculated to a value ha2 (a value of "1" or less). Here, the value ja1, the value ja2, the value ha1, and the value ha2 are predetermined values set in advance for the calculation map Zha. Further, since "ha1> 0.5, ha2 ≦ 1", the distribution ratio Ha of the turning outer wheels is determined to be larger than "0.5" and "1" or less. For example, in the case of "Ha = 0.5", the braking force is evenly generated on the left and right wheels, and the yaw moment due to the difference between the left and right braking forces is not generated. On the other hand, in the case of "Ha = 1", the braking force of the swing suppression control is not generated on the inner wheel with respect to the turning direction, and the braking force is applied only to the outer wheel.

As described above, in the left / right distribution ratio calculation block HA, the turning outer wheel and the turning inner wheel are distinguished based on the actual yaw rate Yr, and the braking force of the turning outer wheel becomes larger than the braking force of the turning inner wheel. Is decided. As a result, a yaw moment is generated due to the difference between the left and right braking forces, and the swing can be effectively suppressed.

Further, the fact that the yaw index Jp is large indicates that the swing is large and fast (a state in which it is suddenly generated). Therefore, the larger the yaw index Jp, the larger the distribution ratio Ha of the turning outer wheels is set. On the other hand, the distribution ratio of the turning inner wheels is determined by "1-Ha", and is set smaller as the yaw index Jp is larger. Therefore, the larger the yaw index Jp, the greater the yaw moment generated by the laterality of the braking force. As a result, the yaw moment that opposes the rocking of the vehicle is increased, and the periodic rocking is effectively canceled.

In the front-back distribution ratio calculation block HB, the front-back distribution ratio Hb is calculated based on the yaw index Jp and the calculation map Zhb. The front-rear distribution ratio Hb is a distribution ratio between the front and rear wheels for allocating the total braking force Fv (target value) for achieving the target deceleration Gt to the braking force of the front and rear wheels. Here, the front-rear distribution ratio Hb is a ratio to the left and right front two wheels. Therefore, the ratio of the rear two wheels is "1-Hb".

The front-rear distribution ratio (ratio of the front two wheels) Hb is calculated to the value hb1 (value of "0" or more) when the yaw index Jp is less than the value jb1 based on the calculation map Zhb. When the yaw index Jp is greater than or equal to the value jb1 and less than the value jb2, the front-back distribution ratio Hb is calculated to increase as the yaw index Jp increases. Then, when the yaw index Jp is a value jb2 or more, the front-back distribution ratio Hb is calculated to a value hb2 (a value of "1" or less). Here, the value jb1, the value jb2, the value hb1, and the value hb2 are predetermined values set in advance for the calculation map Zhb. Further, since “hb1 ≧ 0, hb2 ≦ 1”, the front-back distribution ratio Hb is determined to be “0” or more and “1” or less. When "Hb = 1", the swing suppression control does not apply the braking force Fr * to the rear wheel WHr *, but increases only the braking force Ff * of the front wheel WHf *. On the other hand, in the case of "Hb = 0", the braking force is not applied to the front wheel WHf * by the swing suppression control, and only the braking force of the rear wheel WHr * is increased.

The front wheel WHf * has a larger capacity for generating braking force than the rear wheel WHr *. In addition, increasing the braking force Ff * of the front wheels WHf * has a higher effect of suppressing rocking than increasing the braking force Fr * of the rear wheels WHr *. However, if the front wheel braking force Ff * is increased too much, momentary understeer behavior may occur. This understeer behavior gives the driver a sense of discomfort, albeit for a very short time. Therefore, the larger the yaw index Jp, the larger the braking force Ff * (target value) of the front wheel WHf * is set, and the smaller the braking force Fr * (target value) of the rear wheel WHr * is set.

As described above, in the front-rear distribution ratio calculation block HB, when the yaw index Jp is relatively large, the distribution ratio Hb for the front wheels WHf * is set relatively large, and the front wheel braking force Ff * determines the distribution ratio Hb. The rocking is surely suppressed. On the other hand, when the yaw index Jp is relatively small, the front wheel distribution ratio Hb is set to be relatively small, and the instantaneous understeer behavior caused by the increase in the front wheel braking force Ff * can be suppressed.

In each wheel braking force calculation block FW (corresponding to step S200), the target braking force Fw ** of each wheel WH ** is calculated based on the total braking force Fv, the left-right distribution ratio Ha, and the front-rear distribution ratio Hb. Will be done. Specifically, the total braking force Fv is distributed to the braking force (target value) Fw ** of each wheel WH ** based on the left-right distribution ratio Ha and the front-rear distribution ratio Hb. For example, the target braking force Fwfs of the turning outer front wheel is "Fwfs = Fv · Ha · Hb", the target braking force Fwrs of the turning outer rear wheel is "Fwrs = Fv · Ha · (1-Hb)", and the turning inner front wheel. The target braking force Fwfu is "Fwfu = Fv · (1-Ha) · Hb", and the target braking force Fwru of the rear wheel inside the turn is "Fwru = Fv · (1-Ha) · (1-Hb)". Each is calculated.

In each wheel servo processing block SV (corresponding to step S210), the braking torque applied to each wheel WH ** is servo-controlled based on each wheel braking force Fw ** (target value). Here, the servo control is a control that quickly brings the actual value closer to (matches) the target value. For example, in each wheel servo processing block SV, the detection value (braking fluid pressure) Pw ** of the braking fluid pressure sensor PW is adopted as a state variable, and feedback control based on the braking fluid pressure Pw is executed. In this case, the target hydraulic pressure Pt ** is converted and calculated based on each wheel braking force Fw **. Then, in the braking actuator BR (particularly, the hydraulic pressure unit HU), the actual braking hydraulic pressure Pw matches the target hydraulic pressure Pt based on the target hydraulic pressure Pt and the braking hydraulic pressure Pw (detection value). Feedback control is performed.

The braking fluid pressure sensor PW ** may be omitted. In this case, in each wheel servo processing block SV, slip servo control is executed with the deceleration slip (simply also referred to as “wheel slip”) Sw ** of the wheels as a state variable. In the servo control based on the wheel slip Sw, when the deceleration slip Sw of the wheel is not excessive (that is, when the wheel slip Sw is within a predetermined range), the wheel slip Sw and the wheel braking force F are in a proportional relationship. Based on being. For example, the wheel slip (state amount) Sw ** is performed, and the wheel speed Vw **, the vehicle body speed Vx, and the deviation (slip speed) hV ** are used. Further, as the wheel slip Sw **, the wheel slip ratio obtained by dividing the above speed deviation hV ** by the vehicle body speed Vx can be adopted.

Specifically, in each wheel servo processing block SV, each wheel target braking force Fw ** is converted into a target slip St **. Further, the actual wheel slip Sw ** is calculated based on the wheel speed Vw ** and the vehicle body speed Vx. Then, feedback control regarding the wheel slip is executed in the braking actuator BR (particularly, the hydraulic pressure unit HU) so that the actual wheel deceleration slip Sw ** approaches and matches the target slip St **.

<Action / effect>
The actions and effects of the motion control device CS according to the present invention will be summarized below.
The motion control device CS is mounted on a towing vehicle composed of a tractor VH and a trailer TR towed by the tractor VH. The motion control device CS includes a yaw rate sensor YR that detects the actual yaw rate Yr of the tractor VH, a wheel speed sensor VW that detects the speed of each wheel WH of the tractor VH as the wheel speed Vw, and each wheel based on the actual yaw rate Yr. It is provided with a controller ECU that increases the braking force of the WH and executes damping control (swing suppression control) that attenuates the periodic yaw motion (swing) of the towed vehicle caused by the trailer TR.

In the motion control device CS, the vehicle body speed (traveling speed) Vx of the tractor VH is calculated by the controller ECU based on the wheel speed Vw. The total sum (total braking force) Fv of the braking force F ** acting on the tractor VH is calculated based on the vehicle body speed Vx of the tractor VH. The total braking force Fv (target value) is distributed to the braking force Fw ** of each wheel WH ** based on the actual yaw rate Yr. For example, based on the actual yaw rate Yr, the turning outer wheel and the turning inner wheel are discriminated in the turning direction of the tactile VH. The total braking force Fv is distributed to the left and right wheels so that the braking forces Fwfs and Fwrs of the turning outer wheels are larger than the braking forces Fwfu and Fwru of the turning inner wheels.

The larger the vehicle body speed Vx, the more likely the rocking occurs, and the smaller the vehicle body speed Vx, the less likely it is to occur. In the motion control device CS, the total braking force Fv is determined based on the vehicle body speed Vx, and this is distributed to the target value Fw ** of each wheel braking force based on the actual yaw rate Yr. Therefore, there is no excess or deficiency in the braking force acting on the entire vehicle, and stable swing suppression control can be executed at all times. Further, since the braking forces Fwfs and Fwrs of the turning outer wheels are made larger than the braking forces Fwfu and Fwru of the turning inner wheels, a yaw moment that cancels the swing can be effectively formed.

In the motion control device CS, a yaw index (swing index) Jp representing the degree of yaw motion (that is, swing) is calculated based on the actual yaw rate Yr. Then, based on the yaw index Jp, the larger the yaw index Jp, the larger the total braking force Fv. That is, the yaw index Jp is taken into consideration in determining the total braking force Fv. The greater the degree of rocking, the greater the total braking force Fv is adjusted so that a larger vehicle deceleration can be obtained. Thereby, the swing can be surely suppressed.

As the yaw index Jp, "peak value Yp of actual yaw rate Yr (absolute value of extremum Yo, Yc)", "peak value Ep of calculated yaw rate Ye (absolute value of extremum Eo, Ec)", "yaw angle acceleration dY" At least one of "peak value dYp (extreme value Do, absolute value of Dc)" and "peak value hYp (extreme value Ho, Hc) of yaw rate deviation hY (= Yr-Yt)" is adopted. Will be done. Here, each peak value Yp, Ep, hYp, dYp is determined based on the maximum value and the minimum value in one cycle of periodic fluctuation in each state quantity Yr, Ye, hY, dY.

Further, as the yaw index Jp, instead of the above peak values Yp, Ep, hYp, and dYp, the maximum values Ym, Em, hYm, and dYm of various state quantities Yr, Ye, hY, and dY can be adopted. Each maximum value Ym, Em, hYm, dYm is a maximum value in a plurality of cycles from the start to the end of the swing. Therefore, the maximum values Ym, Em, hYm, and dYm are determined based on the peak values Yp, Ep, hYp, and dYp. However, the peak values Yp, Ep, hYp, and dYp represent the degree of fluctuation for each cycle in the fluctuation that changes from moment to moment. Therefore, it is desirable that peak values Yp, Ep, hYp, and dYp are adopted as the state quantity (yaw index) Jp representing the periodic yaw motion of the towing vehicle.

In addition, in the front-rear distribution of the braking force, the larger the yaw index Jp, the larger the braking force Ff * of the front wheels WHf * is set, and the smaller the braking force Fr * of the rear wheels WHr * is set. In the swing suppression, the increase of the front wheel braking force Ff * is more effective than the increase of the rear wheel braking force Fr *. However, an excessive increase in front wheel braking force Ff * may cause transient understeer behavior, which the driver may find uncomfortable. Therefore, the distribution Hb of the braking force of the front and rear wheels is adjusted based on the yaw index Jp. As a result, when the yaw index Jp is large, the fluctuation is surely suppressed. Further, when the yaw index Jp is small, the above-mentioned understeer behavior can be effectively suppressed, and the driver's discomfort can be reduced.

<Other embodiments>
Hereinafter, other embodiments will be described. In other embodiments, the same effect as described above is obtained.
In the above embodiment, the configuration of the disc type braking device (disc brake) has been exemplified. In this case, the friction member MS is a brake pad, and the rotating member KT is a brake disc. A drum type braking device (drum brake) may be adopted instead of the disc type braking device. In the case of a drum brake, a brake drum is adopted instead of the caliper CP. Further, the friction member MS is a brake shoe, and the rotating member KT is a brake drum.

In the above embodiment, as a device for applying the braking torque to the wheel WH, a hydraulic type device via a braking fluid has been exemplified. Instead of this, an electric one driven by an electric motor may be adopted. In the electric device, the rotational power of the electric motor is converted into linear power, whereby the friction member MS is pressed against the rotary member KT. Therefore, the braking torque is directly generated by the electric motor regardless of the pressure of the braking liquid. Further, a composite type configuration may be formed in which a hydraulic type using a braking fluid is adopted for the front wheels and an electric type is adopted for the rear wheels.

In the above embodiment, a trailer TR including two wheels WHt * has been exemplified. The trailer TR may include four wheels or more.

VH ... tractor, TR ... trailer, CS ... motion control device, ECU ... controller, BR ... braking actuator, VW ... wheel speed sensor, YR ... yaw rate sensor, GX ... front-rear acceleration sensor, GY ... lateral acceleration sensor, SA ... steering angle Sensor, BA ... Braking operation amount sensor, Yr ... Actual yaw rate (detection value), Yp ... Yorate peak value, Jp ... Yao index, Vx ... Body speed, Fv ... Total braking force (target value), Fw ... Each wheel braking force (Target value), Ha ... Left-right distribution ratio (ratio of front and rear wheels on the outside of turning), Hb ... Front-rear distribution ratio (ratio of two front wheels).

Claims (2)

In a towed vehicle motion control device including a tractor and a trailer towed by the tractor.
A yaw rate sensor that detects the actual yaw rate of the tractor, and
A wheel speed sensor that detects the speed of each wheel of the tractor as the wheel speed,
A controller that increases the braking force of each wheel based on the actual yaw rate and performs damping control that attenuates the periodic yaw motion of the towing vehicle caused by the trailer.
Equipped with
The controller
The vehicle body speed of the tractor is calculated based on the wheel speed, and the vehicle body speed is calculated.
The total braking force acting on the tractor is calculated as the total braking force based on the vehicle body speed.
A motion control device for a towing vehicle configured to distribute the total braking force to the braking force of each wheel based on the actual yaw rate. In the motion control device for a towing vehicle according to claim 1,
The controller
Based on the actual yaw rate, a yaw index representing the degree of the yaw movement is calculated.
A motion control device for a towing vehicle configured so that the larger the yaw index, the greater the correction of the total braking force.

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