JP2018158673A - Motion control device for traction vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motion control device for a traction vehicle for restraining rocking of the traction vehicle, the motion control device having substantially constant effect regardless of a loading state of a trailer.SOLUTION: A motion control device for a traction vehicle including a tractor and a trailer towed by the tractor executes rocking restraint control for restraining periodic rocking of the traction vehicle caused by the trailer by increasing a braking torque of a wheel of the tractor. In the rocking restraint control, a load equivalent value regarding a load of a rear wheel of the tractor is acquired, and a control parameter of the rocking restraint control is adjusted based on this load equivalent value. Specifically, the control parameter is adjusted so that execution of the rocking restraint control is more easy to start as the load equivalent value is smaller. The control parameter is also adjusted so that an increase in the braking torque caused by the rocking restraint control is larger as the load equivalent value is smaller.SELECTED DRAWING: Figure 2

Description

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

  Patent Document 1 states that “in a method for stabilizing an automobile (particularly a passenger car) having a trailer towed by an automobile, the automobile is monitored for rolling motion, and when the rolling motion is detected, the automobile In other words, a substantially periodic yaw moment having an approximately opposite phase to the rolling motion is automatically generated.

  Patent Document 2 states that “a behavior control device that executes generation of an anti-yaw moment for suppressing a sway state of a connected vehicle by braking force distribution control, and the vehicle is not decelerated when the anti-yaw moment is generated. Thus, in order to provide a behavior control device that can avoid the driver's uncomfortable feeling and the influence on the following vehicle, the sway state is suppressed by the braking force distribution control of each wheel when the sway state occurs. It is described that when a yaw moment is generated, a driving force determined based on a deceleration amount of the vehicle by a braking force generated on each wheel by the braking force distribution control is applied to the driving wheel of the vehicle.

  Patent Documents 1 and 2 describe a control device that controls the sway behavior (also referred to as “swing”) of a tow vehicle by controlling the braking torque of a wheel. The swing of the tow vehicle is generated due to the trailer, and the degree depends on the state of the trailer. This will be described with reference to FIG.

  The schematic diagram in FIG. 6A shows the loaded state of the trailer TR. The upper diagram (X) shows a state in which the load loaded on the trailer TR is substantially disposed on the trailer wheel WHt *. On the other hand, in the lower figure (Y), the load is loaded on the rear part of the trailer TR. In the state as shown in (Y), the rear portion of the tractor VH is lifted by the hitch HCT which is a connecting portion between the tractor VH and the trailer TR. Therefore, compared with the state (X), the front wheel load Fzf * is increased, but the rear wheel load Fzr * is decreased. Since the running stability of the tow vehicle is ensured by the lateral force of the rear wheel WHr *, in the state of (Y), the rear wheel load Fzr * is reduced and the generation of the rear wheel lateral force Fyr * is reduced.

  The characteristic diagram of FIG. 6B is a result of investigating the influence of the difference in the loading state on the yaw rate fluctuation in the trail way control (also referred to as “swing suppression control”) TSC employing the same control parameter. For the reason described above (reduction of the rear wheel load Fzr * of the tractor VH), the yaw rate fluctuation is larger in the state (Y) than in the state (X). Therefore, a motion control device that suppresses the swinging of the towing vehicle is desired to have a constant effect without depending on the loaded state of the trailer TR.

Special table 2003-503276 gazette JP 2011-079470 A

  An object of the present invention is to provide a tow vehicle motion control device that suppresses swinging of a tow vehicle, the effect of which is substantially constant regardless of the loaded state of a trailer.

  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 tow vehicle according to the present invention is based on a behavior sensor (YRA, GYA) for detecting a yawing behavior (Yra, Gya) of the tractor (VH) and the yawing behavior (Yra, Gya, hYr). A controller that increases the braking torque of the wheels (WH **) of the tractor (VH) and executes swing suppression control (TSC) that suppresses periodic swing of the tow vehicle caused by the trailer (TR). (ECU).

  In the tow vehicle motion control device according to the present invention, the controller (ECU) acquires a load equivalent value (Jfzr) related to a load (Fzr *) of a rear wheel (WHr *) of the tractor (VH), and The control parameters (Ayj, Nyj, Gxc, Hzr) of the swing suppression control (TSC) are adjusted based on the load equivalent value (Jfzr). For example, the controller (ECU) adjusts the control parameters (Ayj, Nyj) so that the swing suppression control (TSC) is more easily started as the load equivalent value (Jfzr) is smaller. Further, the controller (ECU) adjusts the control parameter (Gxc) such that the smaller the load equivalent value (Jfzr) is, the larger the increase in the braking torque by the swing suppression control (TSC) is.

  Depending on the loaded state of the trailer TR, the load (vertical force) Fzr * of the rear wheel of the tractor VH varies, and the possible lateral force changes. For this reason, the effectiveness of the swing suppression control TSC also changes due to the loaded state of the trailer TR. According to the above configuration, the state quantity (rear wheel load equivalent value) Jfzr corresponding to the rear wheel load of the tractor VH is calculated, and based on this, various control parameters (Ayj, etc.) of the swing suppression control TSC are adjusted. The As a result, the effectiveness of the swing suppression control TSC can be maintained substantially constant regardless of the loaded state of the trailer TR.

  For example, as the rear wheel load equivalent value Jfzr is smaller, the control parameters related to the start of the swing suppression control TSC (that is, the threshold amplitude Ayj and the threshold number Nyj) are adjusted to be smaller. As a result, the swing suppression control TSC is easily started. Therefore, the control can be executed only when the swing suppression is necessary.

  Further, as the rear wheel load equivalent value Jfzr is smaller, the control parameter (that is, the target deceleration Gxc) related to the strength (control amount) of the swing suppression control TSC is adjusted to be larger. As a result, the braking torque increased by the swing suppression control TSC is increased. As the rear wheel load equivalent value Jfzr is smaller, the stability of the tow vehicle is more likely to be impaired. However, by the adjustment, the swing suppression control TSC is appropriately executed, and the stability of the tow vehicle can be suitably maintained.

1 is an overall configuration diagram of a vehicle equipped with a tow vehicle motion control device according to the present invention. It is the schematic for demonstrating the arithmetic processing in a controller. It is a functional block diagram for demonstrating the start / end determination processing of swing suppression control. It is a time series diagram for demonstrating the calculation of a peak value, and control start determination. It is a functional block diagram for demonstrating each wheel braking torque process. It is the schematic for demonstrating a subject, and a characteristic view.

<Symbols of components, subscripts at the end of symbols, and moving directions>
An embodiment of a tow vehicle motion control apparatus MCS according to the present invention will be described with reference to the drawings. In the following description, components having the same symbol, such as “YRA”, arithmetic processing, signals, characteristics, and values have the same function. The subscript “**” added to the end of each symbol indicates whether the front / rear / left / right four wheels of the tractor VH or the left / right two wheels of the trailer TR are related. Specifically, in the tractor VH, each subscript corresponds to “fl” for the left front wheel, “fr” for the right front wheel, “rl” for the left rear wheel, and “rr” for the right rear wheel, respectively. doing. In the trailer TR, “tl” corresponds to the left wheel and “tr” corresponds to the right wheel. Further, the subscript “**” may be omitted. “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.

  For example, the wheel speed sensor VWA ** (represented as “VWA” when the subscript ** is omitted) is a wheel speed sensor VWAfl for the left front wheel, a wheel speed sensor VWAfr for the right front wheel, and for the left rear wheel. A wheel speed sensor VWArl for the right rear wheel and a wheel speed sensor VWArr for the right rear wheel are comprehensively shown. Further, the wheel speed sensor VWAf * indicates wheel speed sensors VWAfl and VWAfr for front wheels, and the wheel speed sensor VWAr * indicates wheel speed sensors VWArl and VWArr for rear wheels.

<Overall Configuration of Tow Vehicle Movement Control Device According to the Present Invention>
The motion control apparatus MCS 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 constituted by a tractor VH and a trailer TR towed by the tractor VH.

  A towing vehicle (particularly a tractor VH) equipped with a motion control device MCS includes a braking operation member BP, a braking operation amount sensor BPA, a steering operation member SW, a steering angle sensor SWA, a wheel speed sensor VWA **, a yaw rate sensor YRA, front and rear An acceleration sensor GXA, a lateral acceleration sensor GYA, a brake fluid pressure sensor PWA **, a hitch sensor JHT, a brake actuator (also simply referred to as “actuator”) BRK, and a controller ECU are provided. The tractor VH is provided with a power source PWR and a transmission TRN for accelerating the tow vehicle and traveling at a constant speed.

  The braking operation member (for example, a brake pedal) BP is a member that the driver operates 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 a braking force is generated on the wheel WH. The braking operation member BP is provided with a braking operation amount sensor (also simply referred to as “operation amount sensor”) BPA. An operation amount Bpa of the braking operation member (brake pedal) BP by the driver is detected by the operation amount sensor BPA. Specifically, as the brake operation amount sensor BPA, a hydraulic pressure sensor that detects the pressure of the master cylinder MC, an operation displacement sensor that detects an operation displacement of the brake operation member BP, and an operation force of the brake operation member BP are detected. At least one of the operation force sensors is employed. Accordingly, the brake operation amount Bpa is determined based on at least one of the hydraulic pressure of the master cylinder MC, the operation displacement of the brake operation member BP, and the operation force of the brake operation member BP. The braking operation amount Bpa is input to the controller ECU.

  A steering operation member (for example, a steering wheel) SW is a member operated by the driver to turn the vehicle. By operating the steering operation member SW, a steering angle Swa is given to the steered wheels (for example, the front wheels WHf *), and the vehicle is turned. The steering operation member SW is provided with a steering angle sensor SWA so as to detect the steering angle Swa. The steering angle sensor SWA detects the rotation angle (steering angle) Swa from the steering neutral position “Swa = 0” corresponding to the straight traveling of the vehicle. The steering angle Swa is input to the controller ECU.

  Further, although not shown, an acceleration operation member (for example, an accelerator pedal) that is operated by the driver to adjust the output of the power source PWR of the vehicle and accelerate the vehicle is provided. Further, a shift operation member (for example, a shift lever) for performing a shift operation is provided by the transmission TRN. An acceleration operation amount sensor that detects an operation amount of the acceleration operation member and a shift position sensor that detects a shift position of the speed change operation member are provided. In addition, a wheel load sensor that detects a load acting on the wheel WH and a vehicle height sensor that detects a vehicle height (a height with respect to a road surface) may be provided. When a pneumatic type suspension is used, an air pressure sensor for detecting the air pressure in the chamber can be provided. The detected signal (acceleration operation amount or the like) is input to the controller ECU.

  A power source PWR (for example, an internal combustion engine) is provided with a throttle sensor THA that detects a throttle opening degree Tha, an injection amount sensor FIA that detects a fuel injection amount Fia, and a rotation speed sensor NEA that detects a drive rotation speed Nea. It is done. The transmission TRN is provided with a gear position sensor GRA for detecting a gear ratio (gear position) Gra. The throttle opening Tha, the fuel injection amount Fia, the drive speed Nea of the power source, and the gear position Gra are employed to calculate the output from the power train of the vehicle (general name of the power source PWR and the transmission TRN). The When the power source PWR is an electric motor for driving, an energization amount (for example, a current value) to the power source PWR can be detected. Signals obtained by the sensors are input to the controller ECU via a communication bus CMB described later.

  The tractor VH includes a wheel speed sensor VWA ** that detects a wheel speed Vwa ** that is a rotation speed of the wheel WH **, and a yaw rate sensor YRA that detects an actual yaw rate Yra (corresponding to "yaw behavior"). (Equivalent to “behavior sensor”), longitudinal acceleration sensor GXA for detecting longitudinal acceleration Gxa in the longitudinal direction, and lateral acceleration sensor GYA for detecting lateral acceleration Gya (equivalent to “yaw behavior”) (“behavior sensor”) And a pressure sensor PWA ** for detecting the brake fluid pressure Pwa ** of the wheel cylinder WC **. These detection signals (Vwa ** and the like) are input to the controller ECU.

  Tractor VH and trailer TR are connected by hitch HTC. The hitch HTC is a connecting device composed of a traction bracket and a coupling ball added so that the trailer TR can be pulled by a general vehicle such as a passenger car. The hitch HTC is provided with a hitch sensor JHT that detects a towing state. The hitch sensor amount Jht is detected by the hitch sensor JHT. Here, the hitch state quantity Jht includes a load acting on the hitch HTC (force acting on the vehicle in the vertical direction and the front-rear direction, hitch load), hitch angle φ (an angle on a plane perpendicular to the road surface). Is included. The hitch state quantity Jht is input to the controller ECU.

  The vehicle wheel WH ** is provided with a brake caliper CP **, a wheel cylinder WC **, a rotating member KT **, and a friction member MS. Specifically, a rotating member (for example, a brake disc, simply expressed as “KT”) KT ** is fixed to the wheel WH, and a brake caliper CP ** (simply simply “CP” is sandwiched therebetween). Is also arranged). A brake caliper (simply referred to as “caliper”) CP is provided with a wheel cylinder WC ** (also simply referred to as “WC”). By adjusting (increasing or decreasing) the hydraulic pressure in the wheel cylinder WC, the piston in the wheel cylinder WC is moved (advanced or retracted) with respect to the rotating member KT. By this movement of the piston, the friction member (for example, 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 together. For this reason, braking torque (braking force) is generated in the wheel WH by the frictional force generated by the pressing force.

  A brake actuator (also simply referred to as “actuator”) BRK is connected to a wheel cylinder WC ** via a brake pipe HK **. The actuator BRK includes a known master cylinder MC and a hydraulic unit HU. For example, the hydraulic unit HU includes a plurality of solenoid valves, a hydraulic pump, an electric motor, and the like. When brake control including the swing suppression control TSC is not executed, the brake fluid pressure Pwa corresponding to the operation of the brake operation member BP by the driver is caused by the actuator BRK (particularly, the master cylinder MC) to the wheel cylinder WC of each wheel WH. Respectively. A braking torque corresponding to the operation amount Bpa of the braking operation member (brake pedal) BP is applied to each wheel WH. When executing braking control such as anti-skid control, traction control, vehicle stability control (including swing suppression control), etc., the actuator BRK (particularly the hydraulic unit HU) is independent of the operation of the braking operation member BP. Thus, the brake hydraulic pressure Pwa for each wheel cylinder WC is controlled, and the brake torque is adjusted for each wheel WH.

  The vehicle includes an actuator BRK and an electronic control unit (also referred to as a “controller”) ECU that is electrically connected to the various sensors (such as YRA). The controller ECU is a microcomputer composed of a plurality of independent controller ECUs (ECUb, ECUp, etc.) connected by a communication bus CMB. For example, the controller ECUb is a controller for the actuator BRK, and the controller ECUp is a controller for the power source PWR. Each controller (ECUb etc.) in the controller ECU executes a dedicated control program. Various sensor signals (sensor values) and signals (internally calculated values) calculated in each controller are shared via the communication bus CMB.

  Arithmetic processing of this device (processing of swing suppression control TSC) is programmed in a controller (electronic control unit) ECU (for example, a braking controller ECUb). In the controller ECU, braking control is executed based on signals from the steering angle sensor SWA, the wheel speed sensor VWA, the yaw rate sensor YRA, the lateral acceleration sensor GYA, and the like. Further, based on the wheel speed Vwa of each wheel WH detected by the wheel speed sensor VWA, the vehicle traveling speed (body speed) Vxa is calculated by a known method.

<Calculation processing in the controller>
With reference to the schematic diagram of FIG. 2, an outline of calculation processing in the controller ECU b will be described. In the controller ECU (particularly, the ECU b), the swing suppression control TSC is executed. The “swing suppression control” suppresses periodic swinging (sway behavior) of the tow vehicle caused by the trailer TR, and is also referred to as “damping control” or “trailer way control”. The processing in the controller ECUb includes a rear wheel load equivalent value calculation block JFZR and a swing suppression control block TSB.

  In the rear wheel load equivalent value calculation block JFZR, a rear wheel load equivalent value Jfzr is calculated. The rear wheel load equivalent value Jfzr is a state quantity (state variable) corresponding to the load (vertical force) of the rear wheel WHr *, and is determined as a larger value as the rear wheel load is larger. The rear wheel load equivalent value Jfzr is determined based on a signal acquired from the communication bus CMB. Specifically, the rear wheel load equivalent value Jfzr is the load of the rear wheel WHr * itself, the air pressure of the air suspension, the vertical load of the hitch HTC, the hitch angle φ (the pulling attitude in the vertical plane, see FIG. 6A). And calculation based on at least one of the vehicle body heights.

  The rear wheel load is detected by a load sensor provided on the rear wheel WHr *. Further, based on the wheel speed Vwa, the wheel resonance frequency, the dynamic load radius of the wheel, and the μ gradient of the wheel (the gradient at which the friction coefficient μ changes with respect to the slip ratio) are acquired, and based on these, Wheel load can be estimated (see JP 2004-67009 A).

  In a vehicle employing an air suspension, the rear wheel load equivalent value Jfzr is determined based on the air pressure in the air chamber. The air pressure is detected by an air pressure sensor. Further, the air pressure can be estimated from the operating states of the compressor and the air valve.

  The rear wheel load equivalent value Jfzr is calculated based on the hitch state quantity Jht. The hitch state quantity Jht is detected by a hitch sensor JHT provided in the hitch HTC. The larger the hitch state quantity Jht, the larger the rear wheel load equivalent value Jfzr is determined. Specifically, a hitch sensor JHT detects a vertical load (hitch load) acting on the hitch HTC as a hitch state quantity Jht. As the hitch load in the direction of gravity (downward) is larger, the hitch state quantity Jht is acquired as a larger value. Further, the angle (hitch angle) of the hitch HTC in the vertical plane (also referred to as a vertical plane and perpendicular to the horizontal plane) can be adopted as the hitch state quantity Jht. The smaller the hitch angle, the larger the hitch state quantity Jht is determined.

  Since the spring constant of the suspension spring is substantially constant, the rear wheel load equivalent value Jfzr is determined based on the vehicle height (body height) on the rear wheel shaft. The vehicle height is detected by a vehicle height sensor. As the vehicle height of the rear wheel axle is smaller (lower), the rear wheel load equivalent value Jfzr is determined to be larger. The rear wheel load equivalent value Jfzr calculated by the rear wheel load equivalent value calculation block JFZR is input to the swing suppression control block TSB.

  In the swing suppression control block TSB, swing suppression control is executed based on the rear wheel load equivalent value Jfzr and the like. In the swing suppression control block TSB, it is determined whether or not a sway behavior (swing) due to the trailer TR has occurred. When the swing behavior occurs, the target braking torque of each wheel WH is determined by the swing suppression control block TSB so as to suppress (attenuate) the swing behavior, and the target value matches the actual value. Actuator BRK is driven. Since the braking torque has a one-to-one correspondence with the braking hydraulic pressure (hydraulic pressure in the wheel cylinder WC), a case where the braking hydraulic pressure is employed as the braking torque will be described below. The swing suppression control block TSB includes a target braking torque calculation process MTQ and a braking torque servo process SRV.

  In the target braking torque calculation process MTQ, the target braking torque (that is, the target hydraulic pressure) Pwt of each wheel WH is determined so as to execute the swing suppression control. The target braking torque calculation process MTQ includes a swing suppression control start / end determination process and each wheel braking torque process.

  In the start / end determination process of the target braking torque calculation process MTQ, it is determined based on the yawing behavior (Yra, Gya, etc.) of the vehicle whether or not to start swing suppression control. Here, the yawing behavior (actual values) Yra and Gya of the vehicle are detected by behavior sensors YRA and GYA. The start of the swing suppression control TSC is determined based on, for example, the amplitude of the yawing behavior calculated based on the time series waveforms of the periodic yawing behavior Yra and Gya. In the start / end determination process, the rear wheel load equivalent value Jfzr is taken into consideration, and the threshold value for each determination is adjusted. Specifically, the determination threshold (corresponding to “control parameter”) is changed so that the swing suppression control TSC is more easily started as the load equivalent value Jfzr is smaller. On the other hand, when the load equivalent value Jfzr is relatively large, the determination threshold value is corrected so that it is difficult to start the swing suppression control TSC. This is because when the rear wheel load equivalent value Jfzr is relatively small, “the swing of the connected vehicle is relatively likely to occur, and therefore, the swing suppression control TSC needs to be intervened earlier. Based on the reason.

  When the swing suppression control start condition is satisfied, the target braking torque (target hydraulic pressure) Pwt of each wheel WH is determined in each wheel braking torque process of the target braking torque calculation process MTQ. Here, the target hydraulic pressure Pwt is determined based on the rear wheel load equivalent value Jfzr. Specifically, the control parameter is adjusted such that the smaller the load equivalent value Jfzr is, the larger the increase in the target braking torque of the front wheels WHf * (that is, the target hydraulic pressure of the front wheels) Pwtf * due to the swing suppression control TSC. The This is because when the rear wheel load equivalent value Jfzr is relatively small, “in order to improve vehicle stability by the swing suppression control TSC, a larger vehicle deceleration Gxa is necessary”, and This is based on the reason that the application of braking torque to the front wheels WHf * is effective for obtaining the vehicle deceleration Gxa because the load on the rear wheels WHr * is relatively small.

  In the braking torque servo process SRV, servo control is executed based on the target hydraulic pressure Pwt and the actual hydraulic pressure Pwa. In the braking torque servo process SRV, so-called feedback control is executed so that the actual hydraulic pressure Pwa matches the target hydraulic pressure Pwt. Specifically, a deviation (control error) hPw between the target value Pwt and the actual value Pwa is calculated, and the actuator BRK is controlled so that the hydraulic pressure deviation hPw approaches “0”. Here, the actual hydraulic pressure Pwa is detected by the braking hydraulic pressure sensor PWA.

The servo torque control (referred to as “hydraulic servo control”) based on the target value Pwt and the actual value Pwa related to the brake hydraulic pressure (the hydraulic pressure of the wheel cylinder WC) has been described above.
The braking force of the wheel WH is generated by the front / rear slip of the wheel WH (the difference between the vehicle body speed Vxa and the wheel speed Vwa, also referred to as “braking slip”). For this reason, the wheel slip (difference between the vehicle body speed Vxa and the wheel speed Vwa) has a one-to-one correspondence with the braking force of the wheel WH. Therefore, instead of the method based on the brake fluid pressure described above, servo control of braking torque (referred to as “wheel speed servo control”) can be executed based on wheel slip. Specifically, the target wheel speed Vwt is calculated by subtracting the required wheel slip from the vehicle body speed Vxa. Then, the actual wheel speed Vwa and the target wheel speed Vwt are compared, so that the actual value Vwa of the wheel speed approaches the target value Vwt (the deviation between the target value Vwt and the actual value Vwa approaches “0”). As such, the actuator BRK can be controlled. That is, servo control based on the wheel speed Vwa (wheel speed servo control) can be employed as servo control of the braking torque.

<Start / end judgment of swing suppression control>
With reference to the functional block diagram of FIG. 3, the start / end determination process of the swing suppression control in the target braking torque calculation process MTQ will be described. The start / end determination process includes a peak value calculation block YRP, a threshold amplitude calculation block AYJ, a threshold number calculation block NYJ, and a start / end determination block HNT. If the execution of the swing suppression control TSC is not instructed in the determination process, the control flag FLsc is set to “0”. On the other hand, when execution of the swing suppression control TSC is instructed, the control flag FLsc is set to “1”. Therefore, the time when the control flag FLsc is changed from “0” to “1” (calculation cycle) is the control start time, and the time when the control flag FLsc is changed from “1” to “0” (calculation cycle) is the time when the control ends. It is. Here, the control flag FLsc is a signal for instructing the execution state of the swing suppression control TSC.

  In the peak value calculation block YRP, the maximum value Ypo and the minimum value Ypc of the yaw rate Yra are calculated based on the time series data of the yaw rate Yra after the filter processing. Here, the maximum value Ypo and the minimum value Ypc are generally referred to as “peak value”. In the yaw rate Yra, the previous calculated value Yra (n−1) and the current calculated value Yra (n) are compared. When the yaw rate Yra is increasing, the yaw rate at the time point (calculation cycle) when “Yra (n)> Yra (n−1)” is switched to “Yra (n) <Yra (n−1)”. Yra (n−1) is stored as the maximum value Ypo. Here, “n” represents a calculation cycle. As in the case where the yaw rate Yra is increasing, when the yaw rate Yra is decreasing, “Yra (n) <Yra (n−1)” is switched to “Yra (n)> Yra (n−1)”. At the time (calculation cycle), the yaw rate Yra (n-1) is stored as the minimum value Ypc. The peak values Ypo and Ypc are input to the start / end determination block HNT.

  In the threshold amplitude calculation block AYJ, the threshold amplitude Ayj is calculated based on the rear wheel load equivalent value Jfzr and the calculation map EZay. In the swing suppression control TSC, the swing amplitude is calculated based on the maximum value Ypo and the minimum value Ypc, and the swing magnitude (degree) is determined based on the amplitude. Based on the threshold amplitude Ayj, it is determined whether or not the swing is large enough to execute the swing suppression control TSC. That is, the threshold amplitude Ayj is a threshold value for determining the swing amplitude, and is one of the control parameters of the swing suppression control TSC. The threshold amplitude Ayj is input to the start / end determination block HNT.

  The calculation map EZay for the threshold amplitude Ayj is set so that the threshold amplitude Ayj becomes the value ay1 when the rear wheel load equivalent value Jfzr is less than the value ja1. When the rear wheel load equivalent value Jfzr is greater than or equal to the value ja1 and less than the value ja2, the threshold amplitude Ayj monotonously increases from the value ay1 to the value ay2 as the rear wheel load equivalent value Jfzr increases (in other words, the rear wheel As the load equivalent value Jfzr decreases, the threshold amplitude Ayj monotonically decreases from the value ay2 to the value ay1). When the rear wheel load equivalent value Jfzr is greater than or equal to the value ja2, the threshold amplitude Ayj is set to the value ay2. That is, the threshold amplitude Ayj is limited by the lower limit value ay1 and the upper limit value ay2, but is calculated to increase as the rear wheel load equivalent value Jfzr increases. Here, the value ja1, the value ja2, the value ay1, and the value ay2 are predetermined values set in advance for the operation map EZay.

  In the threshold number calculation block NYJ, the threshold number Nyj is calculated based on the rear wheel load equivalent value Jfzr and the calculation map EDZy. In the swing suppression control block TSB, the swing suppression control TSC is started when multiple swings occur (appear) in order to avoid the influence of noise or the like. The threshold number Nyj is a threshold value for determining the number of occurrences of swing Nyd in the start condition of the swing suppression control TSC, and is one of the control parameters of the swing suppression control TSC. The threshold number Nyj is input to the start / end determination block HNT.

  The calculation map EDZy for the threshold number Nyj is set so that the threshold number Nyj becomes the value ny1 when the rear wheel load equivalent value Jfzr is less than the value jn1. When the rear wheel load equivalent value Jfzr is not less than the value jn1 and less than the value jn2, the threshold number Nyj is sequentially increased from the value ny1 to the value ny2 as the rear wheel load equivalent value Jfzr increases (in other words, the rear wheel As the load equivalent value Jfzr decreases, the threshold number Nyj is sequentially decreased from the value ny2 to the value ny1). When the rear wheel load equivalent value Jfzr is greater than or equal to the value ja2, the threshold number Nyj is set to the value ny2. Here, the threshold number Nyj, the value ny1, and the value ny2 are natural numbers. The threshold number Nyj is limited by the lower limit value ny1 and the upper limit value ny2, but is calculated to increase sequentially by “1” as the rear wheel load equivalent value Jfzr increases. Here, the value jn1, the value jn2, the value ny1, and the value ny2 are predetermined values set in advance for the operation map EDny.

  In the start / end determination block HNT, based on the maximum value Ypo, the minimum value Ypc, the threshold amplitude Ayj, and the threshold number Nyj, the start and end of the swing suppression control TSC are determined. Specifically, a deviation (absolute value) | Ayp | between the maximum value Ypo and the minimum value Ypc is calculated. Then, the magnitude of the deviation (that is, the amplitude of the yaw rate Yra) Ayp is compared with the threshold amplitude Ayj. When the absolute value of the amplitude Ayp is greater than or equal to the threshold amplitude Ayj (| Ayp | ≧ Ayj), “1 (times)” is added to the number of swings Nyd. However, when the absolute value of the amplitude Ayp is less than the threshold amplitude Ayj (| Ayp | <Ayj), “1” is not added to the number of swings Nyd and is left as it is. That is, in the start / end determination block HNT, the number of times that the condition “| Ayp | ≧ Ayj” is satisfied (the number of swings) Nyd is calculated. When the swing number Nyd reaches the threshold number Nyj (calculation cycle), the start of the swing suppression control TSC is determined. That is, the control flag FLsc output from the start / end determination block HNT is switched from “0” to “1”.

  In the start / end determination block HNT, the end of the swing suppression control TSC is determined based on the swing count Nyd. Specifically, at the time (calculation cycle) when the time during which the number of swings Nyd is not increased (the time during which the condition “| Ayp | <Ayj” is satisfied) becomes equal to or longer than a predetermined time tkx. Then, the swing suppression control TSC is terminated. That is, the control flag FLsc is switched from “1” to “0”. Further, when the vehicle body speed Vxa becomes less than the predetermined speed vxx, the swing suppression control TSC can be ended. Here, the predetermined time tkx and the predetermined speed vxx are preset threshold values (predetermined values) for end determination.

  The processing for starting and ending the swing suppression control TSC based on the peak values Ypo and Ypc of the yaw rate Yra has been described above. As another example, instead of the actual yaw rate Yra, a value “Gya / Vxa” obtained by dividing the actual lateral acceleration Gya by the vehicle body speed Vxa may be employed. Here, since the state quantity “Gya / Vxa” is a physical quantity of the same dimension as the yaw rate Yra, it is also referred to as “calculation yaw rate Yre”. Similarly to the above, the maximum value Yqo of the calculation yaw rate Yre and the minimum value Yqc of the calculation yaw rate Yre are calculated based on the time-series data of Yre after the filter processing. Then, the deviation between the maximum value Yqo and the minimum value Yqc is calculated as the amplitude Ayq of the calculation yaw rate Yre and is compared with the threshold amplitude Ayj. When the amplitude Ayq (absolute value) is greater than or equal to the threshold amplitude Ayj (| Ayq | ≧ Ayj), the swing number Nyd is increased by “1”, and the swing number Nyd is increased by the threshold number Nyj. When this is the case (when “Nyd = Nyj” is established), the swing suppression control TSC is started. Further, the swing suppression control TSC ends when the time during which the swing number Nyd does not increase reaches the predetermined time tkx.

  The steering angle Swa can be referred to for the integration of the number of swings Nyd. Specifically, as a condition for increasing the number of swings Nyd, “the direction of the steering angle Swa does not match the direction of the actual yaw rate Yra (or the calculated yaw rate Yre, ie, the actual lateral acceleration Gya). Can be added. In other words, even if the condition “| Ayp | ≧ Ayj” (or “| Ayq | ≧ Ayj”) is satisfied, the steering angle Swa and the actual yaw rate Yra (or the calculated yaw rate Yre) are in the same direction. In this case, the number of swings Nyd is not increased. Depending on the condition, the swing caused by the steering angle Swa can be distinguished. The “direction” is a direction in which the vehicle turns, and includes a right direction and a left direction.

  In order to reduce the influence of the steering angle Swa, a yaw rate deviation hYr can be employed instead of the actual yaw rate Yra and the calculated yaw rate Yre. Based on the steering angle Swa and the vehicle body speed Vxa, the target yaw rate Yrt is calculated. The difference between the actual yaw rate Yra and the target yaw rate Yrt (ie, “Yra−Yrt”) is determined as the yaw rate deviation hYr. Similarly to the above, the maximum value Yho and the minimum value Yhc are calculated based on the time series data of the yaw rate deviation hYr. In the yaw rate deviation hYr, the difference between the maximum value Yho and the minimum value Yhc is calculated as the amplitude Ahy and compared with the threshold amplitude Ayj. When the amplitude Ahy (absolute value) is equal to or greater than the threshold amplitude Ayj (| Ahy | ≧ Ayj), the swing number Nyd is increased by “1”, and the swing number Nyd is increased by the threshold number Nyj. When this is the case (when “Nyd = Nyj” is established), the swing suppression control TSC is started.

  In the start / end determination block HNT, the start and end of the swing suppression control TSC can be determined based on time-series data of a plurality of state quantities (Yra and the like). Therefore, the oscillation suppression control TSC starts and ends with at least one of the actual yaw rate (detected yaw rate) Yra, the calculated yaw rate Yre (= Gya / Vxa), and the yaw rate deviation hYr (= Yra−Yrt) (“ It can be determined on the basis of “yaw behavior”. That is, at least one of the three amplitudes Ayp, Ayq, and Ahy is calculated, and compared with the threshold amplitude Ayj determined based on the rear wheel load equivalent value Jfzr, the number of swings Nyd is calculated. The Then, the threshold number Nyj determined based on the rear wheel load equivalent value Jfzr is compared with the swing number Nyd, and the start of the swing suppression control TSC is determined.

  At least one of the threshold amplitude Ayj and the threshold number Nyj is increased as the rear wheel load equivalent value Jfzr is increased, and is decreased as the rear wheel load equivalent value Jfzr is decreased. For this reason, as the rear wheel load equivalent value Jfzr is larger, the swing suppression control TSC is less likely to be started. As the rear wheel load equivalent value Jfzr is smaller, the swing suppression control TSC is easier to start. The loaded state of the trailer TR affects the rear wheel load equivalent value Jfzr. However, since the rear wheel load equivalent value Jfzr is taken into consideration in the start condition of the swing suppression control TSC, the swinging is performed only when necessary. The suppression control TSC is executed, and its effectiveness can be made substantially constant.

<Calculation of peak value and control start determination>
The peak value calculation and control start / end determination will be described with reference to the time-series diagram of FIG. As described above, at least one of the detected yaw rate Yra, the calculated yaw rate Yre, and the yaw rate deviation hYr is adopted as the state quantity (that is, the yawing behavior of the vehicle) for executing the swing suppression control TSC. Since the processing is the same for any state quantity, a case where the detected yaw rate Yra is employed will be described as a representative example. Here, the threshold amplitude Ayj is set based on the rear wheel load equivalent value Jfzr. Further, the threshold number Nyj is determined to be “3” based on the rear wheel load equivalent value Jfzr.

  When the towing vehicle starts to swing, the peak value (maximum value, minimum value) of the yaw rate Yra is calculated. For example, the maximum value Ypo [0] is determined and stored at time t0 after the maximum value Ypo [0] of the yaw rate Yra actually occurs. Thereafter, the minimum value Ypc [1] is calculated at time t1 after the minimum value Ypc [1] of the yaw rate Yra actually occurs. At time t1, the amplitude Ayp [1] is calculated as an absolute value of “Ypc [1] −Ypo [0]”. At the time point t1, the amplitude Ayp [1] is less than the threshold amplitude Ayj, and therefore the number of swings Nyd remains “0”. The processing is continued sequentially.

  At time t5, the minimum value Ypc [5] in the current calculation cycle is compared with the stored maximum value Ypo [4], and the amplitude Ayp [5] (= | Ayp [5] −Ayp [4]. |) Is calculated. At time t5, since the amplitude Ayp [5] is equal to or greater than the threshold amplitude Ayj, the number of swings Nyd is increased from “0” to “1”. However, since the swing count Nyd is less than the threshold count Nyj (= 3), the swing suppression control TSC is not started.

  At time t6, the amplitude Ayp [6] (= | Ayp [6] −Ayp [5] |) is calculated and satisfies “Ayp [6] ≧ Ayj”, so the number of oscillations Nyd is “2”. Will be increased. Further, at time t7, the amplitude Ayp [7] (= | Ayp [7] −Ayp [6] |) is calculated and satisfies “Ayp [7] ≧ Ayj”. 3 ”. Since the number of swings Nyd reaches the threshold number Nyj at time t7, execution of the swing suppression control TSC is started. That is, the control flag FLsc is changed from “0” to “1”.

  At time t8, the amplitude Ayp [8] is calculated, and “Ayp [8] ≧ Ayj” is satisfied, so that the swing count Nyd increases to “4” while the swing suppression control TSC is executed. Is done. When the number of swings Nyd is sequentially increased, the swing suppression control TSC is continuously executed and the state of “FLsc = 1” is maintained.

  When the vehicle body speed Vxa is reduced by the execution of the swing suppression control TSC and the swing of the tow vehicle converges, the amplitude Ayp of the yaw rate Yra decreases. For example, the amplitude Ayp [13] is calculated at time t13, but since “Ayp [13] <Ayj”, the number of swings Nyd is not increased. Then, at time t16 when the state of “Ayp <Ayj” is continued for a predetermined time tkx, the swing suppression control TSC is ended. If the condition “Vxa <vxx” is satisfied before the time point t16, the execution of the swing suppression control TSC can be ended at the time point. Therefore, the control flag FLsc is switched from “1” to “0”.

  When “Ayp ≧ Ayj” is satisfied, the swing suppression control TSC is not immediately started, and the start of the swing suppression control TSC is determined based on the number of times Nyd where “Ayp ≧ Ayj” is satisfied. The For this reason, the influence of noise is compensated, and execution of the reliable swing suppression control TSC can be achieved. In addition, one of the control parameters of the threshold amplitude Ayj and the threshold number Nyj is determined based on the rear wheel load equivalent value Jfzr. As a result, adjustment is made so that the effect of the swing suppression control TSC is substantially constant without depending on the loaded state of the trailer TR.

<Determination of target braking torque>
With reference to the functional block diagram of FIG. 5, the determination of the target braking torque in each wheel WH (each wheel braking torque process of the target braking torque calculation process MTQ) will be described.

  As described above, components, operations, signals, characteristics, and values that have the same symbols are of the same function. The subscript “**” added to the end of each symbol indicates whether the front / rear / left / right four wheels of the tractor VH or the left / right two wheels of the trailer TR are related. Specifically, in the tractor VH, each subscript corresponds to “fl” for the left front wheel, “fr” for the right front wheel, “rl” for the left rear wheel, and “rr” for the right rear wheel, respectively. doing. In the trailer TR, “tl” corresponds to the left wheel and “tr” corresponds to the right wheel. Further, the subscript “**” may be omitted. “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, as described above, the braking torque is calculated by the brake fluid pressure or the wheel speed dimension. However, the target values Pwt and Vwt of each wheel WH are calculated, and the actuator BRK is servo-controlled so that the actual values Pwa and Vwa detected by the sensors PWA and VWA coincide with the target values Pwt and Vwt. no change. Here, what is based on the brake fluid pressure will be described as a representative example. Therefore, in the following description, “target hydraulic pressure Pwt” replaced with “target wheel speed Vwt” corresponds to a determination method based on wheel speed (braking slip).

  Each wheel braking torque process of the target braking torque calculation process MTQ includes a vehicle body speed calculation block VXA, a yaw angular acceleration calculation block DYR, a required deceleration calculation block GXQ, a target deceleration calculation block GXC, a left / right distribution ratio calculation block HSS, and a front / rear distribution. It is comprised by ratio calculation block HZR and each wheel target braking torque calculation block PWT.

  In the vehicle body speed calculation block VXA, the vehicle body speed Vxa is calculated based on the wheel speed Vwa detected by the wheel speed sensor VWA of each wheel WH. For example, when the vehicle is not braked (including acceleration), the vehicle body speed Vxa is determined based on the slowest wheel speed Vwa. Further, when the vehicle is braked, the vehicle body speed Vxa is determined based on the fastest wheel speed Vwa.

  In the yaw angular acceleration calculation block DYR, the yaw angular acceleration dYr is calculated based on the yaw rate Yra. Specifically, the yaw rate Yra is time-differentiated, and the yaw angular acceleration dYr is calculated.

  In the required deceleration calculation block GXQ, the required deceleration Gxq is calculated based on the braking operation amount Bpa and the calculation map EZgq. The required deceleration Gxq corresponds to the longitudinal acceleration of the vehicle corresponding to the driver's braking operation. Specifically, based on the calculation map EZgq, when the braking operation amount Bpa is less than a predetermined value bp0, the required deceleration Gxq is set to “0”. If the braking operation amount Bpa is greater than or equal to the value bp0 and less than the value bp1 (predetermined value), the required deceleration Gxq is calculated to increase as the braking operation amount Bpa increases. When the braking operation amount Bpa is equal to or greater than the value bp1, the required deceleration Gxq is calculated to a value gq1 (predetermined value). Here, the predetermined value bp0 is a preset value corresponding to the play of the braking operation member BP.

  In the target deceleration calculation block GXC, the target deceleration Gxc is calculated based on the vehicle body speed Vxa, the rear wheel load equivalent value Jfzr, and the calculation map EZgc. The target deceleration Gxc is a vehicle deceleration (target value) generated by the swing suppression control TSC, which is necessary to attenuate the periodic swing of the tow vehicle, and is a control parameter of the swing suppression control TSC. (State variable). Specifically, based on the calculation map EZgc, if the vehicle body speed Vxa is less than the value vx0, the target deceleration Gxc is not calculated (or remains “0”), and the swing suppression control TSC is executed. Not. However, when the vehicle body speed Vxa is greater than or equal to the value vx0 and less than the value vx1, the target deceleration Gxc is calculated to the value gc1. When the vehicle body speed Vxa is greater than or equal to the value vx1 and less than the value vx2, the target deceleration Gxc is calculated to increase as the vehicle body speed Vxa increases. When the vehicle body speed Vxa is equal to or greater than the value vx2, the target deceleration Gxc is calculated to the value gc2.

  Further, the target deceleration Gxc is calculated so as to increase as the rear wheel load equivalent value Jfzr decreases based on the calculation map EZgc. In other words, the target deceleration Gxc is calculated so as to decrease as the rear wheel load equivalent value Jfzr increases. Here, the value vx0, the value vx1, the value vx2, the value gc1, and the value gc2 are predetermined values set in advance for the operation map EZgc.

  The requested deceleration Gxq and the target deceleration Gxc are added to calculate the command deceleration Gxt. The command deceleration Gxt is a final target value of the vehicle deceleration that takes into account the driver's braking operation. Note that, when the braking operation member BP is not operated and is not being braked, “Gxq = 0”, and therefore, “Gxt = Gxc” is determined. The command deceleration Gxt is input to each wheel target braking torque calculation block PWT.

  In the left / right distribution ratio calculation block HSS, the left / right distribution ratio Hss is calculated based on the yaw angular acceleration dYr and the calculation map EZsy. The left / right distribution ratio Hss is a distribution ratio between the left and right wheels (target value of the outer wheel in the yaw rate Yra direction) for allocating the total braking force for achieving the command deceleration Gxt to the braking force of the left and right wheels. Specifically, based on the calculation map EZsy, when the absolute value (magnitude) | dYr | of the yaw angular acceleration dYr is less than the value dy1, the left / right distribution ratio (outer wheel ratio) Hss is the value hs1 (“0.5 ”Or more). When the magnitude | dYr | of the yaw angular acceleration is greater than or equal to the value dy1 and less than the value dy2, the left / right distribution ratio Hss is calculated to increase as the yaw angular acceleration magnitude | dYr | increases. When the magnitude of the yaw angular acceleration | dYr | is equal to or greater than the value dy2, the left / right distribution ratio Hss is calculated as a value hs2 (a value equal to or less than “1”). Here, the value dy1, the value dy2, the value hs1, and the value hs2 are predetermined values set in advance for the operation map EZsy. Furthermore, since “hs1 ≧ 0.5, hs2 ≦ 1”, the left / right distribution ratio Hss is determined to be “0.5” or more and “1” or less. When “Hss = 0.5”, the braking force is evenly generated on the left and right wheels by the swing suppression control TSC, and the yaw moment due to the left-right difference of the braking force is not generated. On the other hand, in the case of “Hss = 1”, the braking force of the swing suppression control TSC is not generated on the inner wheel with respect to the turning direction, and the braking force is applied only to the outer wheel.

  A large yaw angular acceleration magnitude | dYr | corresponds to a large degree of oscillation. For this reason, as the magnitude of the yaw angular acceleration | dYr | is larger, the distribution ratio Hss of the turning outer wheel is set to be larger. On the other hand, the distribution ratio of the turning inner wheel is determined by “1-Hss”, and is set to be smaller as the magnitude of the yaw angular acceleration | dYr | is larger. For this reason, as the magnitude of the yaw angular acceleration | dYr | increases, the yaw moment generated by the left-right difference in braking force increases. As a result, the periodic swing is easily canceled. An increase in the left / right distribution ratio (the ratio of the turning outer wheel) Hss corresponds to an increase in the yaw moment that opposes the swinging of the vehicle.

  In the front / rear distribution ratio calculation block HZR, the front / rear distribution ratio Hzr is calculated based on the rear wheel load equivalent value Jfzr and the calculation map EZhz. The front / rear distribution ratio Hzr is a distribution ratio (target value of the rear wheel ratio) between the front and rear wheels for allocating the total braking force for achieving the command deceleration Gxt to the braking force of the front and rear wheels, and swing suppression control It is one of TSC control parameters (state variables). Specifically, based on the calculation map EZhz, when the rear wheel load equivalent value Jfzr is less than the value jh1, the front / rear distribution ratio Hzr is calculated to a value hz1 (a value equal to or greater than “0”). When the rear wheel load equivalent value Jfzr is greater than or equal to the value jh1 and less than the value jh2, the front / rear distribution ratio (rear wheel ratio) Hzr increases as the rear wheel load equivalent value Jfzr increases. When the rear wheel load equivalent value Jfzr is greater than or equal to the value jh2, the front / rear distribution ratio Hzr is calculated to a value hz2 (a value equal to or less than “1”). Here, the value jh1, the value jh2, the value hz1, and the value hz2 are predetermined values set in advance for the operation map EZhz. Furthermore, since “hz1 ≧ 0, hz2 ≦ 1”, the front-rear distribution ratio Hzr is determined to be “0” or more and “1” or less. When “Hzr = 0”, the braking force is not increased on the rear wheel WHr * but only the braking force on the front wheel WHf * is increased by the swing suppression control TSC. On the other hand, in the case of “Hzr = 1”, the braking force is not applied to the front wheel WHf * by the swing suppression control TSC, and only the braking force of the rear wheel WHr * is increased.

  In the rear wheel WHr *, the braking force that can be generated is large when the rear wheel load equivalent value Jfzr is large, but the braking force that can be generated is small when the rear wheel load equivalent value Jfzr is small. . For this reason, the larger the rear wheel load equivalent value Jfzr, the larger the front / rear distribution ratio (rear wheel ratio) Hzr, and the smaller the rear wheel load equivalent value Jfzr, the smaller the front / rear distribution ratio Hzr. On the other hand, since the front wheel distribution ratio Hzf is determined by “1-Hzr”, the larger the rear wheel load equivalent value Jfzr is, the smaller the front wheel ratio Hzf is set. The smaller the rear wheel load equivalent value Jfzr is, the smaller the front wheel is. The ratio Hzf is set large.

  In each wheel target braking torque calculation block PWT, the target hydraulic pressure Pwt ** of each wheel WH ** is calculated based on the command deceleration Gxt, the left / right distribution ratio Hss, and the front / rear distribution ratio Hzr. Specifically, based on the command deceleration Gxt, a total braking force (target value) Fxt acting on the entire towing vehicle is calculated. For example, the total braking force Fxt is calculated by “Fxt = Mvt (mass of towing vehicle) · Gxt”. Then, based on the left / right distribution ratio Hss and the front / rear distribution ratio Hzr, the total braking force Fxt is distributed to the braking force (target value) of each wheel WH. For example, the target braking force Fxfst of the turning outer front wheel is “Fxfst = Fxt · Hss · (1−Hzr)”, and the target braking force Fxrst of the turning outer rear wheel is “Fxrst = Fxt · Hss · Hzr”, the turning inner front wheel. The target braking force Fxfut of the vehicle is “Fxfut = Fxt · (1−Hss) · (1−Hzr)”, and the target braking force Fxrut of the rear inner wheel is “Fxrut = Fxt · (1−Hss) · Hzr”. Are each calculated. Based on the target braking force (Fxfst etc.) of each wheel WH, the final target hydraulic pressure Pwt ** is calculated.

  As described above, based on the rear wheel load equivalent value Jfzr, the target deceleration Gxc and the front / rear distribution ratio Hzr, which are the control parameters of the swing suppression control TSC, are adjusted, and the braking torque target value Pwt ** ( Alternatively, Vwt **) is determined. The smaller the rear wheel load equivalent value Jfzr is, the more easily the stability of the towing vehicle is impaired. For this reason, the target deceleration Gxc is determined to be larger as the rear wheel load equivalent value Jfzr is smaller. As a result, the braking torque increased by the swing suppression control TSC is increased. Further, the smaller the rear wheel load equivalent value Jfzr, the smaller the increase in the braking torque of the rear wheel WHr *. For example, when the rear wheel load equivalent value Jfzr is less than the value jh1, the braking torque increase of the rear wheel WHr * is not executed by the swing suppression control TSC. Since the target deceleration Gxc and the front / rear distribution ratio Hzr are appropriately adjusted based on the rear wheel load equivalent value Jfzr, the swing suppression control TSC is appropriately executed regardless of the loading state of the trailer TR. This stability can be suitably maintained.

<Other embodiments>
Hereinafter, other embodiments will be described. In other embodiments, the same effect as described above (smoothing of the swing suppression control TSC independent of the loaded state of the trailer TR) is achieved.

  In the above embodiment, the configuration of the disc type braking device (disc brake) is exemplified. In this case, the friction member MS is a brake pad, and the rotating member KT is a brake disk. Instead of the disc type braking device, a drum type braking device (drum brake) may be employed. In the case of a drum brake, a brake drum is employed instead of the caliper CP. The friction member MS is a brake shoe, and the rotating member KT is a brake drum.

  In the above-described embodiment, the hydraulic device via the brake fluid is exemplified as the device that applies the braking torque to the wheel WH. Instead, an electric type driven by an electric motor may be employed. In the electric device, the rotational power of the electric motor is converted into linear power, and thereby the friction member MS is pressed against the rotating member KT. Therefore, the braking torque is directly generated by the electric motor regardless of the pressure of the braking fluid. Further, a composite type configuration in which a hydraulic type via a brake fluid is adopted for the front wheel and an electric type is adopted for the rear wheel can be formed.

  In the above-described embodiment, the trailer TR is illustrated as having two wheels WHt *. The trailer TR may include four wheels or more wheels.

VH ... tractor, TR ... trailer, MCS ... motion control device, MS ... friction member, KT ... rotating member, ECU ... controller, BRK ... braking actuator, VWA ... wheel speed sensor, YRA ... yaw rate sensor, GXA ... longitudinal acceleration sensor, GYA: lateral acceleration sensor, SWA: steering angle sensor, BPA: braking operation amount sensor, TSC: swing suppression control, Yra: yaw rate, Jfzr: load equivalent value, Ayj: threshold amplitude, Nyj: threshold number, Gxc: Target deceleration.

Claims (3)

In a motion control device for a tow vehicle including a tractor and a trailer towed by the tractor,
A behavior sensor for detecting the yawing behavior of the tractor;
A controller that increases a braking torque of the wheels of the tractor based on the yawing behavior, and executes swing suppression control that suppresses periodic swing of the tow vehicle caused by the trailer;
With
The controller is
Obtain a load equivalent value related to the load of the rear wheel of the tractor,
A tow vehicle motion control device configured to adjust a control parameter of the swing suppression control based on the load equivalent value. The movement control device for a tow vehicle according to claim 1,
The controller is a motion control device for a tow vehicle that adjusts the control parameter so that the swing suppression control is more easily started as the load equivalent value is smaller. In the tow vehicle motion control device according to claim 1 or 2,
The controller of the towing vehicle adjusts the control parameter so that the increase in the braking torque by the swing suppression control increases as the load equivalent value decreases.