JP6111779B2 - Control device for each wheel independent drive cart - Google Patents

Description

  The present invention relates to a wheel independent drive cart in which each wheel (four wheels or a plurality of wheels) rotates independently, and particularly uses a control for re-adhering the wheel and a control for coordinating the rotational angular velocities of the plurality of wheels. It relates to the control method.

  In recent years, electric vehicles such as electric trolleys have been required to have a lower floor, and in order to realize this lower floor, independent driving carts for each wheel that omits the wheel shaft have begun to be adopted. Each wheel independent drive carriage is provided with an electric motor and an inverter on each wheel (four wheels or a plurality of wheels), and independently controls the rotation of each wheel. In each wheel independent drive cart, the left and right wheels are not connected by a wheel shaft, so the left and right wheels can be driven separately.

  In an electric vehicle such as an electric carriage, if the friction coefficient (also referred to as the adhesion coefficient) at the wheel / rail is reduced, or if the wheel driving force or braking force is greater than the wheel / rail friction coefficient, May cause idling or gliding. This idling or sliding is a problem because it not only wears out the wheels and rails but also leads to diamond disturbance due to failure to obtain the expected acceleration / deceleration. Therefore, in order to return the wheel from the idling / sliding state, control for reducing the motor driving torque (hereinafter referred to as re-adhesion control) is performed.

  On the other hand, each wheel independent drive cart has a risk of impairing the running stability of the vehicle unless the motor of each wheel is controlled in a coordinated manner, and its control method becomes an important issue. In Patent Document 1 and Patent Document 2, the rotational angular speed of each wheel is detected, the rotational angular speed difference between the left and right wheels is determined for each of the left and right front wheels, and the rotational angular speed difference between the left and right wheels is an arbitrary value. It proposes coordinated control of each wheel to be controlled.

  In addition, as a coordinated control for each wheel, a method is also known in which the average rotational angular velocity of the left and right wheels is a target value, and the deviation between the target value and the detected rotational angular velocity value of each of the left and right wheels is zero.

Japanese Patent Laid-Open No. 08-242506 JP 09-233613 A

  When vehicle control is performed using both the re-adhesion control method and the cooperative control method, an unexpected acceleration / deceleration may occur by performing the cooperative control during the re-adhesion control. Therefore, the inventor of the present application has devised a method for reducing the coordinated control torque for controlling the rotational angular velocities of the left and right wheels to zero when detecting idling / sliding. By this method, the occurrence of unexpected acceleration / deceleration of the vehicle can be suppressed.

  FIG. 6 shows a configuration diagram of the control device 1 for each wheel independent drive carriage to which the above method is applied.

The control device 1 includes a rotational angular velocity detector 2 that detects wheel rotational angular velocity detection values ω _{FL_det} and ω _{FR_det} , a load torque estimation unit 3 that outputs load torque estimation values T _{obs_FL} and T _{obs_FR} , and an idling / sliding detection flag. slip _{_L,} an idling-skid detection section 4 for outputting a slip _{_R,} like left and right wheels pair is the average rotation angular velocity, the cooperative control torque T _{LR_FL} controlling the wheel rotational angular velocity, the wheel cooperative control for outputting a T _{LR_FR} Part 5.

Then, the re-adhesion control unit 6, the load torque estimated value _T obs_FL, T obs_FR, idling-skid detection flag slip _{_L,} slip _{_R,} each wheel cooperative control torque T _{LR_FL,} signal obtained by adding the Notchitoruku command T _notch in T _{LR_FR} The motor driving torques _{Tm_FL} and _{Tm_FR} are output.

Note that each wheel cooperative control unit 5, is slipping-skid detection flag slip _{_L,} if the slip _{_R} becomes a value indicating the idle-planing state, cooperative control torque T _{LR_FL,} configured as T _{LR_FR} becomes 0 ing.

The idling / sliding detection unit 4 can be applied as long as the idling / sliding can be detected by each wheel. As an example, a detection method based on rotational angular acceleration is generally known. In the detection method using rotational angular acceleration, the wheel rotational angular velocity detection value ω _det is differentiated and converted to rotational angular acceleration, and the idling / sliding is detected by comparing the absolute value of the rotational angular acceleration with a predetermined threshold value. doing.

  During idling / sliding, the wheel rotation angular velocity increases rapidly, and the wheel rotation angular velocity continues to increase. In the detection method based on the rotational angular acceleration, since the change in the rotational angular acceleration is used for detection of idling / sliding, it is possible to detect idling / sliding earlier than the detection method based on the rotational angular velocity.

However, when rotational angular acceleration is used when both wheel cooperative control and re-adhesion control are used together, a change in rotational angular acceleration caused by input of cooperative control torques _{TLR_FL} and _{TLR_FR} may be erroneously detected as idling / sliding. was there.

  A specific example will be described based on the graphs of FIGS.

FIGS. 7 and 8 show wheel rotation angular velocity detection values ω _{FL_det} , ω _{FR_det} , motor drive torques T _{m_FL} , T _{m_FR} , wheel rotation angular acceleration α _det , idling / The sliding detection flags _{slip_L} and _{slip_R} are shown. 7 shows a case where cooperative control is not applied, and FIG. 8 shows a case where each wheel cooperative control is applied. Further, the road surface friction coefficient at this time is constant.

As shown in FIG. 7, when each wheel cooperative control is not applied, the left and right wheel rotation angular velocity detection values ω _{FL_det} and ω _{FR_det} vary when entering the curve, but the left and right wheel wheels when entering the curve Since _{changes in} the rotational angular velocities ω _{FL_det} , ω _{FR_det} , and rotational angular acceleration α _det are smaller than those in the case of cooperative control, false detection of idling / sliding does not occur.

On the other hand, when each wheel cooperative control is applied, as shown in FIG. 8, the left and right wheel rotational angular velocity detection values ω _{FL_det} and ω _{FR_det} vary when entering the curve. Therefore, each wheel cooperative control unit 5 outputs cooperative control torques T _{LR_FL} and T _{LR_FR} for correcting variation. The cooperative control torque T _{LR_FL,} by T _{LR_FR,} but controls the rotation angular speed difference between the right and left wheels, the cooperative control torque T _{LR_FL,} T _{LR_FR} is largely output when curve rush. As a result, the rotational angular acceleration α _det also temporarily exceeds the idling sliding threshold, and erroneously detects idling / sliding. In the example of FIG. 8, it is assumed that the re-adhesion control does not work.

  As described above, when the wheel rotation angular velocity varies due to a curve or a trajectory irregularity, repeated misdetection of idling / sliding turns off each wheel cooperative control unit 5 each time, and the effect of the cooperative control is expected. It becomes impossible.

  In addition, since the threshold value of the rotational angular acceleration is arbitrarily determined, false detection of idling / sliding can be suppressed by increasing the threshold value. However, if the threshold value is increased, idling / sliding detection is delayed, so that the advantage of performing idling / sliding detection with rotational angular acceleration is lost.

Further, when a time when the rotational angular acceleration α _det exceeds the threshold value has elapsed for a predetermined time, by taking a time threshold value for detecting idling / sliding, the rotational angular acceleration α _det instantaneously reaches the threshold value as shown in FIG. If it exceeds, it is possible not to detect as idling / sliding. However, idling / sliding detection is delayed even when a time threshold is provided.

  As described above, in each wheel independent drive bogie that uses both wheel coordination control and re-adhesion control, it is an issue to suppress the detection delay of idling / sliding and to prevent false detection of idling / sliding. Become.

  The present invention has been devised in view of the above-described conventional problems. One aspect of the present invention is a control device for each wheel independent drive cart that independently drives and controls each wheel. An idling / sliding detecting unit for detecting the wheel, each wheel cooperative control unit for calculating a cooperative control torque for controlling the rotational angular velocity difference between the left and right wheels based on the detected rotational angular velocity value of each wheel, and the cooperative control torque When the change rate limiting unit that outputs the limited cooperative control torque with the limited change rate and the pair of left and right wheels are not idling or sliding, the value obtained by adding the limited cooperative control torque to the notch torque command is output as the motor drive torque. A re-adhesion control unit that outputs a re-adhesion control torque with reduced torque as a motor drive torque when at least one of the pair of left and right wheels idles and slides. To.

  Further, as another aspect, the idling / sliding detection unit differentiates the rotation angular velocity detection value of the wheel and converts it into rotation angular acceleration, and the absolute value of the rotation angular acceleration is greater than a preset threshold value. The idling / sliding is detected, and the change rate limiting unit limits the rate of change to the cooperative control torque so that the rotational angular acceleration when entering the curve does not exceed the idling / sliding threshold.

  Further, the re-adhesion control unit outputs the re-adhesion control torque to the motor driving torque of the adhered wheels together with the idle / sliding wheels when one of the pair of left and right wheels idles and slides. It is characterized by doing.

  As another aspect, the re-adhesion control unit outputs a re-adhesion control torque as a motor drive torque to a wheel in the idling / sliding state when one of the pair of left and right wheels is idling / sliding, A value obtained by adding the limited cooperative control torque to the notch torque command is output as a motor driving torque to the wheel in the sticking state.

  ADVANTAGE OF THE INVENTION According to this invention, in each wheel independent drive trolley | bogie which uses each wheel cooperative control and re-adhesion control together, it becomes possible to suppress the detection delay of idling / sliding and to suppress false detection of idling / sliding.

It is a block diagram which shows the control apparatus of each wheel independent drive trolley | bogie in embodiment. It is a block diagram which shows the idling / sliding detection part in embodiment. It is a flowchart which shows operation | movement of the control apparatus of each wheel independent drive trolley | bogie in embodiment. It is a graph which shows the re-adhesion control torque in embodiment. It is a graph which shows each waveform of the control device in an embodiment. It is a block diagram which shows the control apparatus of each wheel independent drive trolley which used each wheel cooperative control and re-adhesion control together. It is a graph which shows each waveform of a control device at the time of not applying each wheel cooperation control. It is a graph which shows each waveform of a control device at the time of applying each wheel cooperation control.

[Embodiment]
FIG. 1 shows the configuration of a control device 1A for each wheel independent drive carriage in this embodiment. 1 shows only the configuration of the control device 1A for a pair of left and right wheels, the same applies to the case of four wheels, six wheels,...

  The control device 1A for each wheel independent drive carriage in this embodiment includes a rotation angular velocity detector 2, a load torque estimation unit 3, an idling / sliding detection unit 4, each wheel cooperative control unit 5, and a re-adhesion control unit 6. A change rate limiting unit 7 and an adding unit 8.

The rotational angular velocity detector (for example, resolver / encoder or the like) 2 detects the rotational angular velocities ω _FL and ω _FR of the motors of the respective wheels, and outputs them as detected wheel rotational angular velocity values ω _{FL_det} and ω _{FR_det} . Here, in the case of axle mounting, the detected motor rotation angular velocities ω _FL , ω _FR are directly output as wheel rotation angular velocity detection values ω _{FL_det} , ω _{FR_det} , and in the case of motor mounting, from the motor rotation angular velocities ω _FL , ω _FR The wheel rotation angular velocity detection values ω _{FL_det} and ω _{FR_det} are calculated in consideration of the gear ratio.

The load torque estimated value unit 3, the motor drive torque _T m_FL, T m_FR and wheel rotational angular velocity detected value ω _{FL_det,} ω _{FR_det} from the load torque estimated value T _{Obs_FL,} estimates the _T obs_FR. As a method of calculating the estimated load torque values T _{obs_FL} and T _{obs_FR} , for example, the wheel rotational angular velocity detection values ω _{FL_det} and ω _{FR_det} are multiplied by the inertia moment of the wheel + motor rotor to perform pseudo differentiation, and the motor drive torque T _{For example} , a method of subtracting a pseudo-differentiated value from _{m_FL} and T _{m_FR} can be used.

As shown in FIG. 2, the idling / sliding detection unit 4 receives wheel rotation angular velocities ω _{FL_det} and ω _{FR_det} , _performs differentiation by the pseudo-differentiating unit 41, and converts them into rotation angular acceleration α _det . This rotational angular acceleration α _det is converted into an absolute value by the absolute value conversion unit 42, and the comparator 43 compares whether or not the absolute value of the rotational angular acceleration α _det exceeds a predetermined threshold value. The sliding detection flags _{slip_L} and _{slip_R} are output. The idling / sliding detection flags _{slip_L} and _{slip_R} are logic signals that output “0” in the adhesive state and “1” in the idling / sliding state. Further, the idling / sliding detection unit 4 can be applied to configurations other than the above as long as it can detect idling / sliding with each wheel, and description of other configurations is omitted.

Each wheel coordination control unit 5 _obtains the rotation angular velocity difference between the left and right wheels on the front wheel left and right and the rear wheel left and right based on the detected wheel rotation angular velocity values ω _{FL_det} and ω _{FR_det} of each wheel, and the rotation angular velocity difference between the left and right wheels. The cooperative control torques T _{LR_FL} and T _{LR_FR} for controlling the rotational angular velocity difference are output so that becomes an arbitrary value.

In this embodiment, the cooperative control torques T _{LR_FL} and T _{LR_FR} are output so that the difference between the rotational angular velocities of the left and right wheels becomes zero, and the rotational angular velocities of the left and right wheels are made to coincide with each other in the same manner as in the configuration with the conventional coupling shaft. Stability is improved.

The rate-of-change limiting unit 7 limits the rate of change of the cooperative control torques T _{LR_FL} and T _{LR_FR} so that the rotational angular acceleration α _det when entering the curve does not exceed the idling / sliding threshold. In the present embodiment, the change rate limitation of the cooperative control torques T _{LR_FL} and T _{LR_FR} is determined as a value at which the rotational angular acceleration α _det does not exceed the idling / sliding threshold. Hereinafter, signals output from the change rate limiting unit 7 are referred to as limited cooperative control torques T _{LR_FL} ′, T _{LR_FR} ′.

The adding unit 8 adds the limited cooperative control torques T _{LR_FL} ′, T _{LR_FR} ′ and the _notch torque command T _notch and outputs the result to the re-adhesion control unit 6.

The readhesion control unit 6, Notchitoruku command T _notch + limited cooperative control torque T _{LR_FL} ', Notchitoruku command T _notch + limited cooperative control torque T _{LR_FR',} the load torque estimated value _T obs_FL, T obs_FR, idling-skid detection flag Slip_ _L based on the Slip_ _R, the motor drive torque T _{M_FL,} calculates the _T m_FR.

  Next, the operation of the re-adhesion control unit 6 in the first embodiment will be described based on the flowchart of FIG.

(S1) In the re-adhesion control unit 6, the _notch torque command _Tnotch + the limited cooperative control torque _{TLR_FL} ', the _notch torque command Tnotch + the limited cooperative control torque _{TLR_FR} ', the load torque estimated values _{Tobs_FL} , _{Tobs_FR} , idling / sliding detection The flags _{slip_L} and _{slip_R} are read.

(S2) idling-skid detection flag slip _{_L,} based on the slip _{_R,} determines whether idling-planing state. Slipping-skid detection flag slip _{_L,} at least one of "1" of the slip _{_R} proceeds to S4 as YES if (slipping-sliding state) is, idling-skid detection flag slip _{_L,} both slip _{_R} "0" If it is (adhesion state), it will transfer to S3 as No.

(S3) idling-skid detection flag slip _{_L,} when both slip _{_R} both "0" (tacky), the following (1), (2) the motor drive torque T _{M_FL} of the left and right wheels, output as T _{M_FR} To do.

That is, when both wheels are in an adhesive state, values obtained by adding the limited cooperative control torques T _{LR_FL} ′, T _{LR_FR} ′ to the _notch torque command T _notch are output as motor driving torques T _{m_FL} , T _{m_FR} .

(S4) idling-skid detection flag slip _{_L,} if at least one of the slip _{_R} is "1", the load torque estimated value T _{Obs_FL} during idling-skid sensing, the minimum value of the absolute value of _T obs_FR (when sliding the The maximum value) is held as the holding torque T _Latch until the next idling is detected.

(S5) The following equations (3) and (4) are output as motor drive torques _{Tm_FL} and _{Tm_FR} for the left and right wheels. Since the _re- adhesion control torques T _{re-adaheison_FL} and T _{re-adhesion_FR} in the following equations (3) and (4) are calculated based on the same holding torque T _Latch , the motor drive torques T _{m_FL} , T _{m_FR} has the same value.

Next, an example of the _re-adhesion control torques T _{re-adhesion_FL} and T _{re-adhesion_FR} will be described. FIG. 4 is a diagram illustrating an example of the _re- adhesion control torque T _re-adhension when the idling state is detected while the _notch torque command T _{notch is} increasing (acceleration torque is being input).

At the time of slipping detection, the minimum value (maximum value at the time of sliding) of the absolute values of the load torque estimated values T _{obs_FL} and T _{obs_FR} is held as the holding torque T _Latch and held until the next slipping detection. At the time of slipping detection, the re-adhesion control torque T _re-adhension is reduced to y1 [%] of the load torque estimated value T _obs and held for the slipping return time x1. After the idling return time x1 has elapsed, the re-adhesion control torque is raised with y2 [%] as a target value, and then y2 [%] of the holding torque T _Latch is held for the idling return time x2. The idling return time x2 is a time for increasing the torque immediately after the wheel is re-adhered and suppressing idling / sliding again, thereby more reliably re-adhering. After the idling return time x2, the _re- adhesion control torque T _re-adhension is raised with the _notch torque command T _notch + the limit cooperative control torques T _{LR_FL} and T _{LR_FR} as target values. The idling return times x1, x2 and y1 [%], y2 [%] are set to preset values.

FIG. 5 shows detected wheel rotational angular velocity values ω _{FL_det} , ω _{FR_det} , motor drive torques T _{m_FL} , T _{m_FR} , rotational angular acceleration α _det , idling / sliding detection flag when entering a curved track while traveling on a straight track. _{Slip_L} and _{slip_R} are shown. This is the same as the condition shown in FIG. 7, and the road surface friction coefficient is constant.

When entering the curve, the rotational angular velocity detection values ω _{FL_det} and ω _{FR_det} of the left and right wheels are varied, and cooperative control torques T _{LR_FL} and T _{LR_FR} are output to correct the variations. The cooperative control torques T _{LR_FL} , T _{LR_FR} are limited by the change rate limiting unit 7, so that the limited cooperative control torques T _{LR_FL} ′, T _{LR_FR} ′ added to the _notch torque command T _notch when entering the curve are large. The motor drive torques T _{m_FL} and T _{m_FR} do not vary greatly. Here, since the limitation on the rate of change of the cooperative control torques T _{LR_FL} and T _{LR_FR} is determined as a value that does not exceed the threshold value of the wheel rotation angular acceleration α _det , the rotation angular acceleration α _det is the idling / sliding detection flag _{slip_L.} , _{Slip_R} or more, it becomes possible to suppress false detection of idling. As a result, erroneous detection of idling / sliding due to the cooperative control torques _{TLR_FL} and _{TLR_FR} is suppressed, and it is possible to detect idling / sliding of the wheel only when the maximum friction coefficient of the rail is reduced. It becomes.

Further, in the control device 1 for each wheel independent drive carriage in the present embodiment, the cooperative control torques T _{LR_FL} and T _{LR_FR} are not _set to 0, so that the cooperative control torques T _{LR_FL} and T _{LR_FR} are output even after entering the curve. Yes. As a result, the effect of the cooperative control in each wheel cooperative control unit 6 remains, and by controlling so that the rotational angular velocity difference between the left and right wheels becomes zero, the rotation of the left and right wheels is the same as in the configuration with the conventional coupling shaft. The angular velocities are matched to improve running stability.

  As described above, according to each wheel independent drive carriage in the present embodiment, it is possible to use each wheel cooperative control and re-adhesion control together without erroneous detection of idling.

Further, the wheels slipping, sliding state, the wheel also readhesion control torque T _re-adhesion of the motor drive torque T _{M_FL} adhesive state, by outputting as T _{M_FR,} left and right wheels of the motor drive torque _T m_FL, T m_FR And the yawing torque can be suppressed.

The cooperative control torques T _{LR_FL} and T _{LR_FR} may be values for calculating the deviation of the rotational angular velocities of the pair of left and right wheels from the wheel rotational angular velocity detection values ω _{FL_det} and ω _{FR_det} and setting this deviation to zero. In addition, when idling / sliding is detected, the cooperative control torques _{TLR_FL} and _{TLR_FR} may be _set to zero.

  Furthermore, each wheel cooperative control unit 5 controls the difference in rotational angular velocity between the left and right wheels to be zero when passing through a straight line so that the rotational angular velocities of the left and right wheels coincide with each other in the same manner as in the configuration with the conventional coupling shaft. When passing, the rotational angular velocity control may be performed so that the left and right wheels have an arbitrary rotational angular velocity difference according to the radius of curvature.

Further, in this embodiment, when one of the left and right wheels is in the idling state, the _re-adhesion control torque T _re-adhesion is output to the _adhered wheel together with the idle wheel. A value obtained by adding the limited cooperative control torques _{TLR_FL} ′ and _{TLR_FR} ′ to the _notch torque command Tnotch may be output as the motor driving torques _{Tm_FL} and _{Tm_FR} .

  Furthermore, in the embodiment, only the specific re-adhesion control method has been described in detail. However, any other re-adhesion control method can be applied as long as the torque is reduced.

_{DESCRIPTION OF SYMBOLS 1,1A} ... Control apparatus 2 ... Rotational angular velocity detector 3 ... Load torque estimation part 4 ... Idle / sliding detection part 5 ... Each wheel cooperation control part 6 ... Re-adhesion control part 7 ... Change rate restriction _| limiting part _{Tm_FL} , _{Tm_FR} ... Motor drive torque T _notch ... Notch torque command T _re-adhesion ... _Re-adhesion control torque T _{LR_FL} , T _{LR_FR} ... Cooperative control torque T _{LR_FL} ', T _{LR_FR} ' ... Limit cooperative control torque ω _{FL_det} , ω _{FR_det} ... Wheel rotational angular velocity detection

Claims (3)

It is a control device for each wheel independent drive cart that independently controls each wheel,
An idling / sliding detection unit for detecting idling / sliding of a wheel;
Each wheel cooperative control unit that calculates a cooperative control torque for controlling the rotational angular velocity difference between the left and right wheels based on the detected rotational angular velocity value of each wheel;
A rate-of-change limiting unit that outputs a limit cooperative control torque that limits the rate of change of the cooperative control torque; and
When the pair of left and right wheels are not idling / sliding, the value obtained by adding the limit cooperative control torque to the notch torque command is output as the motor drive torque, and at least one of the pair of left and right wheels idling / sliding A re-adhesion control unit that outputs a re-adhesion control torque with reduced torque as a motor drive torque;
With
The idling / sliding detector is
The wheel angular velocity detection value is differentiated and converted into rotation angular acceleration, and when the absolute value of the rotation angular acceleration is larger than a preset threshold value, idling / sliding is detected,
The change rate limiting unit is
A control device for independent driving carts for each wheel, characterized in that the rate of change of the cooperative control torque is limited so that the rotational angular acceleration when entering a curve does not exceed the idling / sliding threshold. The re-adhesion control unit is
If one of the wheels of the pair of right and left wheels is slipping, sliding, claim 1, characterized with a wheel of the idling-sliding state, to output the re-adhesion control torque to the motor drive torque of wheels tacky The control apparatus of each wheel independent drive trolley of description . The re-adhesion control unit is
When one of the pair of left and right wheels idles and slides, the re-adhesion control torque is output as the motor drive torque to the idle and sliding wheels, and the limited cooperative control torque is applied to the notch torque command for the adhered wheels. 2. The control device for each wheel independent drive carriage according to claim 1 , wherein the added value is output as a motor drive torque.

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