JP7105608B2 - Motor control method and motor control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric motor control method, etc., for detecting the occurrence of slipping or skidding of a driving wheel and controlling the electric motor that drives the driving wheel to perform re-adhesion control of the driving wheel.

Electric cars, electric cars, and the like are known as vehicles that run by driving driving wheels with an electric motor. Hereinafter, an electric train (motor car) will be described as a representative example. Electric trains are accelerated and decelerated by the tangential force (also called adhesive force) between the wheels and rails. If the driving force generated by the torque generated by the electric motor is less than the adhesive force acting on the wheels and rails, the vehicle will stick and run. occurs. When skidding occurs, control is performed to reduce the torque generated by the electric motor to return to sticking running, that is, re-adhesion control (see, for example, Patent Documents 1 and 2).

JP-A-2002-44804 JP 2011-172472 A

However, the main objectives of the conventional re-adhesion control technology development are the method of detecting skidding, suppressing deterioration of ride comfort due to recoil during re-adhesion, reducing the possibility of re-slip occurrence, and maintaining the original torque. In most cases, the main purpose of technological development is to determine whether or not to reduce the torque and control after the torque is reduced. Therefore, it was common to think that the control when reducing the torque generated by the electric motor, that is, the reduction speed is set to a preset fixed value.

The present invention has been made in view of the above-mentioned problems, and its object is to propose a method of adaptively changing the speed at which the torque generated by the electric motor is reduced in re-adhesion control.

The first invention for solving the above problems is
Electric motor control that performs torque reduction control to reduce the torque command value of the electric motor that drives the driving wheels when the occurrence of slipping or sliding (hereinafter referred to as "slipping") of the driving wheels is detected to perform re-adhesion control of the driving wheels. a method,
a reduction speed determination step of determining the reduction speed of the torque command value using the acceleration of the driving wheel as a reference acceleration (for example, corresponding to the reduction speed determination unit 640 in FIG. 6);
a torque reduction control step (for example, corresponding to the re-adhesion control unit 680 in FIG. 6) for performing the torque reduction control for reducing the torque command value according to the determined reduction speed when the occurrence of the slip or skid is detected; ,
A motor control method including

Also, as another invention,
Electric motor control that performs torque reduction control to reduce the torque command value of the electric motor that drives the driving wheels when the occurrence of slipping or sliding (hereinafter referred to as "slipping") of the driving wheels is detected to perform re-adhesion control of the driving wheels. a device,
A reduction speed determination unit (for example, corresponding to the reduction speed determination unit 640 in FIG. 6) that determines the reduction speed of the torque command value using the acceleration of the driving wheel as a reference acceleration;
a torque reduction control unit (corresponding to the re-adhesion control unit 680 in FIG. 6) that performs the torque reduction control to reduce the torque command value according to the determined reduction speed when the occurrence of the slip or skid is detected;
It is also possible to configure a motor control device with

According to the first invention and the like, the acceleration of the driving wheel, which is the detection target of the slip/skid, is used as the reference speed to determine the reduction speed for reducing the torque command value when the slip/skid is detected. In other words, the speed at which the torque generated by the electric motor is reduced can be variably determined based on the acceleration of the driving wheel that is subject to slip skid detection. The acceleration of the driving wheels when slipping or skidding changes due to changes in the circumferential tangential force acting between the wheel rails. By changing the lowering speed based on the acceleration, it is possible to adaptively change the lowering speed of the torque generated by the electric motor.

In addition, the second invention is the first invention,
Based on the detected speed of the driving wheel, a first acceleration detection step (for example, FIG. 6 corresponding to the first acceleration detection unit 612);
Based on the detected speed of the driving wheel, a differential operation and a second smoothing process for smoothing in the direction of the time axis, wherein the smoothing time width is narrower than that of the first smoothing process. A second acceleration detection step (for example, corresponding to the second acceleration detection unit 614 in FIG. 6) for detecting the second acceleration by performing
a slip/skid occurrence detection step (for example, corresponding to the slip/skid detection unit 620 in FIG. 6) of detecting the occurrence of slipping or skidding (hereinafter referred to as "skid/skid") using the first acceleration;
including
The reduction speed determination step is a step of determining a reduction speed of the torque command value using the second acceleration as the reference acceleration,
The torque reduction control step is a step of performing the torque reduction control to reduce the torque command value according to the determined reduction speed in response to the detection of the slip/skid occurrence detection step.
A motor control method.

In the second invention, the differential operation and the first smoothing process may be performed in the same or reverse order, or may be performed at the same time. When they are performed simultaneously, for example, a method of widening the sampling interval of the speed of the driving wheel used for differential calculation can be adopted. The same applies to the differential operation and the second smoothing process.

According to the second invention, based on the detected speed of the driving wheel, the acceleration is detected by performing a differential operation and a smoothing process for smoothing in the direction of the time axis, but the time width for smoothing is wide. Two types of acceleration are detected (obtained) by the first smoothing process and the narrow second smoothing process. Then, the occurrence of skidding is detected using the first acceleration detected using the first smoothing process, and the second acceleration detected using the second smoothing process is used as the reference acceleration. is used to determine the reduction speed of the torque command value.

If the smoothing time width is widened, noise components can be reliably removed, but the time delay increases. On the other hand, if the smoothing time width is narrowed, the time delay is reduced, but the noise component cannot be completely removed, and components other than the main signal component related to the circumferential rotation of the driving wheel by the electric motor remain in the acceleration after detection. more likely to slip.

According to the second invention, the first acceleration detected using the first smoothing process with a wide time width for smoothing is used to detect the occurrence of skidding. When the occurrence of slip/skid is detected, the torque reduction control of the electric motor is performed immediately, so the detection of the occurrence of slip/skid should be done by removing the noise component reliably even if it means sacrificing some time delay. be. On the other hand, the second acceleration detected using the second smoothing process with a narrow time width for smoothing is used to determine the reduction speed of the torque command value after the occurrence of the slip/skid is detected. . When the smoothing time width is wide, the signal after the smoothing process has a large response delay from the events and conditions of the driving wheels. Therefore, by determining the reduction speed of the torque command value using the second acceleration with a narrow smoothing time width, an adaptive torque reduction speed that is in line with the immediate event and situation occurring in the driving wheel as much as possible is determined. It becomes possible to

Further, a third invention is the first or second invention,
The reduction speed determination step determines the reduction speed of the torque command value according to a given broad-sense monotonically increasing function based on the reference acceleration determined between a given minimum reduction speed and a given maximum reduction speed. A step of determining (for example, corresponding to the function setting unit 643 in FIG. 6),
A motor control method.

According to the third invention, basically, the greater the reference acceleration, the greater the speed at which the torque command value is reduced.

Further, a fourth invention is the third invention,
A step of setting the minimum reduction speed and/or the maximum reduction speed based on the train running speed (for example, the reference speed Vm) (for example, corresponding to the minimum maximum value setting unit 641 in FIG. 6);
and a motor control method.

According to the fourth invention, the larger the reference acceleration, the higher the torque command value reduction speed is determined. However, the minimum reduction speed and/or maximum reduction speed are set based on the train running speed. be able to.

Further, a fifth invention is the third or fourth invention,
A tensile force detection step of detecting the wheel circumference tensile force of the driving wheel (for example, corresponding to the vector calculation control device 90 or the re-adhesion control device 60 in FIG. 5);
a step of setting the minimum pull-down speed and/or the maximum pull-down speed based on the wheel circumference tensile force (for example, corresponding to the minimum/maximum value setting unit 641 in FIG. 6);
and a motor control method.

According to the fifth aspect of the present invention, the larger the reference acceleration is, the larger the speed at which the torque command value is reduced is determined. It can be set based on the wheel circumference tensile force of the driven wheels.

Further, a sixth invention is any one of the third to fifth inventions,
A tangential force coefficient equivalent value detection step of detecting the tangential force coefficient equivalent value of the driving wheel (for example, a step performed by the vector calculation control device 90 or the re-adhesion control device 60 in FIG. 5);
a step of setting the minimum pull-down speed and/or the maximum pull-down speed based on the tangential force coefficient equivalent value (for example, a step performed by the minimum and maximum value setting unit 641 in FIG. 6);
and a motor control method.

According to the sixth aspect of the invention, the larger the reference acceleration, the higher the speed at which the torque command value is reduced. It can be set based on the tangential force coefficient equivalent value of the driving wheel. Here, the value equivalent to the tangential force coefficient may of course be the tangential force coefficient itself. It means that it may be a value that shows similar variation (a value that has approximately linearity with the tangential force coefficient) and that can be treated as equivalent or substantially equivalent to the tangential force coefficient.

The figure for demonstrating readhesion control. The figure for demonstrating the determination method of a pull-down speed|rate. The figure which shows the modification of the function for determining a pull-down rate. The figure which shows the modification of the function for determining a pull-down rate. FIG. 2 is a diagram showing a circuit block of a main circuit of an electric train, which is an example to which the present embodiment is applied; FIG. 6 is a block diagram of the re-adhesion control device of FIG. 5; The figure which shows the modification of an idle sliding detection part.

Preferred embodiments of the present invention will be described below with reference to the drawings. In the following, the case where the present invention is applied to an electric train, which is a type of electric train, will be described. It can also be applied to automobiles.

In the following description, the "motor torque" is increased or decreased as appropriate for the sake of simplicity of explanation. It means to let In addition, slipping or sliding is collectively referred to as "slipping", and the description will be mainly about slipping, but this embodiment can be similarly applied to sliding during regenerative braking.

[Overall overview of readhesion control]
FIG. 1 is a diagram for explaining re-adhesion control, and a series of signals from a state of constant acceleration in which no slip/skid occurs to occurrence of slip/skid and re-adhesion by performing readhesion control. Waveforms are shown. With the horizontal axis representing time t, from the top, a graph showing the shaft speed V and the reference speed Vm of the driving shaft to be controlled, a graph showing the acceleration α of the controlled shaft, a graph showing the electric motor torque _τe , and a slip/skid detection signal. , and a graph of the recovery detection signal. In a state in which no skidding occurs, the shaft speed V substantially matches the reference speed Vm, and the motor torque _τe is kept substantially constant. When slipping or skidding occurs, the shaft speed V begins to increase, and the speed difference Vd, which is the difference from the reference speed Vm, increases. Then, at time t1, when the speed difference Vd reaches a predetermined slip/skid detection threshold value Vs, occurrence of slip/skid is detected. Here, the idling/slipping detection signal is turned ON.

Then, the re-adhesion control is activated, and the reduction of the motor torque τ _e (more precisely, the reduction of the motor torque τ _e caused by the reduction of the torque component current due to the reduction of the torque command value) is started. The reduction of the motor torque _τe is continuously performed at a reduction speed Wt determined by a reduction speed determination calculation to be described later. That is, the amount of reduction of the torque _τe is increased. When the motor torque _τe is lowered, the increase in the acceleration α is gradually suppressed and begins to decrease. During this period, the shaft speed V continues to increase, but at time t2 when the acceleration α becomes zero, the increase in the shaft speed V also becomes zero. The fact that the acceleration α has become zero is detected as the start of recovery from idling skid to the original sticky running (recovery detection). Here, the idling/slipping detection signal is turned off, and the recovery detection signal is turned on. Although the acceleration α used for recovery detection is assumed to be zero in the description, it is assumed to be zero for the sake of simplicity of explanation. The start of recovery may be detected when the following conditions are reached.

When the recovery is detected, the reduction of the motor torque _τe is stopped and the reduction amount is held. Then, the decrease in the negative acceleration α is gradually suppressed, and soon it turns to increase. Also, the shaft speed V, which has been deviating from the reference speed Vm, begins to decrease. Then, when the speed difference Vd becomes equal to or less than a predetermined readhesion detection threshold value Vr, it is detected that readhesion has occurred (readhesion detection), and control for the return operation is started. That is, the control for reducing the reduction amount of the held electric motor torque _τe to restore the torque is started. Then, at time t4 when the motor torque _τe returns to a predetermined target torque value (for example, the value at the start of the readhesion control (time t1)), the readhesion control ends. The electric motor torque _τe after this re-adhesion detection is controlled so as to recover over a predetermined recovery time Tt.

Here, the object to be monitored for slip/skid detection and readhesion detection is the shaft velocity V (and thus the velocity difference Vd), but the acceleration α may also be used in addition to the object to be monitored. In addition, although the acceleration α is used as the monitoring target for recovery detection, the shaft speed V (and thus the speed difference Vd) is also used in addition to the monitoring target, and the acceleration α becomes zero or the speed difference Vd becomes the slip/skid detection threshold value Vs. It may be detected as the start of recovery when it becomes equal to or less than the following predetermined threshold.

[Pull-down speed determination calculation]
Next, the principle of the pull-down speed determination calculation will be described. FIG. 2 is a diagram for explaining the outline of the pull-down speed determination calculation. The pull-down speed is determined according to a given broad monotonically increasing function based on a reference acceleration defined between a given minimum pull-down speed X and a given maximum pull-down speed Y. In FIG. 2, the horizontal axis is the reference acceleration, and the vertical axis is the reduction speed of the torque command value (hereinafter abbreviated as "reduction speed" as appropriate).

The reference acceleration is the acceleration .alpha. of the driving wheel, which is the detection target axis of the slip/skid, and is the acceleration when the slip/skid is detected. In determining the pulldown rate, the reference acceleration can be divided into three ranges. They are a low acceleration range RL, a middle acceleration range RM, and a high acceleration range RH. The low acceleration range RL and the high acceleration range RH may or may not be set as ranges. In other words, the entire range may be the range RM, or the range RM may be divided by adding either a low acceleration range RL or a high acceleration range RH.

If the reference acceleration is within the low acceleration range RL, the pull-down speed is set to the minimum pull-down speed X, and if the reference acceleration is within the high acceleration range RH, the pull-down speed is set to the maximum pull-down speed Y. When the reference acceleration is within the middle acceleration range RM, the pulldown speed is determined based on the reference acceleration according to an increasing function defined between the minimum pulldown speed X and the maximum pulldown speed Y.

In the present embodiment, the reference acceleration from zero to the assumed maximum acceleration αb is divided into three fixed ranges: a low acceleration range RL, a medium acceleration range RM, and a high acceleration range RH. may be set variably.
For example, as the speed difference between the maximum pull-down speed Y and the minimum pull-down speed X increases, the medium acceleration range RM is widened, and one or both of the low acceleration range RL and the high acceleration range RH are set to be narrower. good too.

Both the minimum pull-down speed X and the maximum pull-down speed Y correspond to 1) the reference speed Vm, 2) the wheel peripheral tensile force related to the driving wheel, and 3) the tangential force coefficient related to the driving wheel when slipping and skidding is detected. It is set by a function whose variable is the value. The minimum pull-down speed _X is determined by the function _fX , and the function fX calculates a gradually larger value as the reference speed Vm increases, and calculates a gradually larger value as the wheel circumferential tensile force increases, corresponding to the tangential force coefficient. It is a function that calculates a gradually larger value as the value increases. Here, "gradually" means either stepwise or linearly. The maximum pull-down speed _Y is determined by the function fY, and the function _fY similarly calculates a gradually larger value as the reference speed Vm increases, and calculates a gradually larger value as the wheel circumferential tensile force increases. This function calculates a gradually larger value as the force coefficient equivalent value increases. However, the function _fY is defined to calculate a larger value than the function _fX .

The function f _X and the function f _Y are not limited to the case where the three variables are 1) the reference speed Vm, 2) the wheel circumference tensile force related to the driving wheel, and 3) the tangential force coefficient equivalent value related to the driving wheel, A function using one or two of these as variables may be used, or a function for determining the minimum pull-down speed X and the maximum pull-down speed Y further taking into consideration other than these three may be used.

Here, the wheel circumference tensile force F [N] can be calculated by the following formula (1).
F=(G/R)× _τe (1)
where G is the gear ratio, R is the wheel radius [m], and τ _e is the motor torque [Nm].

Also, the tangential force coefficient μ can be calculated by the following equation (2).
μ=(F−m×α)/W ₀ (2)
Here, F is the wheel peripheral tensile force [N], m is the rotational inertia mass [kg], α is the wheel peripheral acceleration [m/s ² ], and _W0 is the stationary wheel load [N].
Since the gear ratio G, the wheel radius R, the rotational inertia mass m, and the stationary wheel load _W0 are known, when performing vector control of the electric motor 10, the electric motor torque _τe is calculated, and the wheel peripheral tensile force F and the tangential force coefficient μ can be calculated.

In addition, the tangential force coefficient equivalent value may of course be the tangential force coefficient μ itself. (a value that has approximately linearity with the tangential force coefficient), and may be a value that can be treated as equivalent or substantially equivalent to the tangential force coefficient μ.

Now, in FIG. 2, the increasing function that determines the pull-down speed when the reference acceleration is within the middle acceleration range RM is shown as a linear graph, but other broadly-defined monotonically increasing increasing functions such as those shown in FIGS. may be That is, as shown in FIG. 3, the function may be determined such that the pull-down speed increases stepwise as the reference acceleration increases, or a high-order function may be used as shown in FIG. In either case, it is a function that gradually increases in value as the reference acceleration increases, and can be said to be an increasing function that monotonously increases in a broad sense. Further, since it is monotonically increasing in a broad sense, it can be said that it is a function representing the entire range of the reference acceleration including the low acceleration range RL and the high acceleration range RH.

[Example]
FIG. 5 is a diagram schematically showing a configuration relating to one example for realizing the present embodiment among the circuit blocks of the main circuit of the electric train, and shows one drive shaft. That is, although the motor control is described below as individual control (so-called 1C1M), the applicable form of the present invention is not limited to this. For example, it can also be applied to 1C2M that collectively controls two driving wheels. According to FIG. 5, the main circuit of the train according to this embodiment includes the electric motor 10, the pulse generator 20, the inverter 30, the current sensor 40, and the electric motor control device 50. FIG.

The electric motor 10 is a main motor that rotationally drives an axle by being supplied with electric power from the inverter 30, and is realized by, for example, a three-phase induction motor. The pulse generator 20 is a rotation detector that detects rotation of the drive shaft, and outputs a PG signal, which is a detection signal, to the readhesion control device 60 and the vector calculation control device 90 . It should be noted that other rotation detectors such as a speed generator may be used instead of the pulse generator. The current sensor 40 is provided at the input end of the electric motor 10 and detects the U-phase and V-phase currents Iu and Iv flowing into the electric motor 10 . DC power is supplied to the inverter 30 via, for example, a pantograph and a converter, or from a battery. The output voltage is adjusted based on the voltage command values Vu ^* , Vv ^* , and Vw ^* of the U-phase, V-phase, and W-phase input from the vector operation control device 90, and AC power is supplied to the electric motor 10.

The electric motor control device 50 vector-controls the electric motor 10 . The motor control device 50 is implemented by a computer or the like including a CPU, ROM, RAM, etc., and may be mounted as a control board as part of the control device of the motor 10, or integrated with the inverter 30, for example. Configured as a device. The electric motor control device 50 also includes a re-adhesion control device 60 and a vector calculation control device 90 .

The re-adhesion control device 60 detects the shaft velocity V of the drive shaft from the PG signal of the pulse generator 20, and further detects the acceleration α by differentiating the same. Then, using the reference speed Vm, the detected shaft speed V and the acceleration α are monitored, and slip/skid detection, recovery detection, and re-adhesion detection are performed, and control is performed to re-adhere the slipping driving wheels. In this re-adhesion control, a torque reduction command signal for controlling the torque generated by the electric motor 10 to cause the driving wheels to re-adhere is generated and output to the vector calculation control device 90 . Here, the reference speed Vm is the traveling speed of the electric train, and may be, for example, the speed obtained from the driver's cab or the shaft speed of the trailing wheel of the T car. Further, among the shaft speeds of the respective shafts in the vehicle, the minimum value may be determined during power running, and the maximum value during braking may be determined.

The vector calculation control device 90 is an excitation current component Id as a d-axis component and a torque current component as a q-axis component (motor torque minute current) Iq, the shaft speed V obtained from the PG signal detected by the pulse generator 20, the current command values Id ^* and Iq ^* input from a current command generation device (not shown), and the readhesion control device 60. The voltage command values Vu ^* , Vv ^* , Vw ^* for the inverter 30 are generated based on the torque reduction command signal or the like. Specifically, while the torque reduction command signal is not input, normal arithmetic processing based on the current command values Id ^* , Iq ^* , etc. is performed to calculate the voltage command values Vu ^* , Vv ^* , Vw ^* , and the torque reduction is performed. When the command signal is input, the voltage command values Vu ^* , Vv ^* , Vw ^* are calculated so as to reduce the torque generated by the electric motor 10 by the amount corresponding to the signal. Here, since the arithmetic processing for calculating the voltage command values Vu ^* , Vv ^* , Vw ^* based on the current command values Id ^* , Iq ^* , etc. is a known arithmetic processing, detailed description thereof will be omitted.

FIG. 6 is a block diagram showing the configuration of the readhesion control device 60. As shown in FIG. The readhesion control device 60 includes a speed detection unit 601, an adder 603, a first acceleration detection unit 612, a second acceleration detection unit 614, a slip/skid detection unit 620, a pull-down speed determination unit 640, It comprises a recovery detection section 660 , a readhesion detection section 670 and a readhesion control section 680 .

Based on the PG signal, the speed detection unit 601 performs rotation detection result smoothing processing for smoothing the rotation detection interval or the number of detections per unit time of the drive shaft in the direction of the time axis to detect the speed. Specifically, the speed is detected by a fixed-time pulse number counting method, an average pulse width counting method, or the like. The smoothing time width Ts is set to a value, such as 25 ms, which provides a certain effect in removing noise components, which are high-frequency vibration components.

The first acceleration detection unit 612 and the second acceleration detection unit 614 each include a differential calculation unit that performs differential calculation on the axial velocity V detected by the speed detection unit 601, and a smoothing unit that performs smoothing in the direction of the time axis. Acceleration is detected with a different smoothing time width. Specifically, the smoothing time width Ta2 of the second acceleration detection unit 614 is set to be narrower than the smoothing time width Ta1 of the first acceleration detection unit 612 . It should be noted that the differential operation may be performed by the differential operation unit after the smoothing unit first smoothes the axial velocity V detected by the velocity detection unit 601 in the direction of the time axis instead of performing the differential operation first. Further, if a method of differentiating the velocity detected at any time by changing the sampling interval of the velocity is adopted, the differential operation and the smoothing process can be performed at the same time. The detection unit 614 may employ this method. In this case, the smoothing time width corresponds to the sampling interval.

If the smoothing time width is widened, the noise component can be removed more reliably, but the time delay increases. On the other hand, if the smoothing time width is narrowed, the time delay is reduced, but the noise component cannot be completely removed, and components other than the main signal component related to the circumferential rotation of the driving wheel by the electric motor remain in the acceleration after detection. more likely to slip.

The first acceleration detection unit 612 detects a first acceleration α1 that is used by the slip/skid detection unit 620 to detect slip/skid. When slip/skid is detected, torque reduction control is started immediately, so noise components should be removed reliably even if it means sacrificing some time delay. requested. Therefore, the smoothing time width Ta1 of the first acceleration detection unit 612 is set to a relatively wide time width, specifically, a longer time width than the smoothing time width Ta2 of the second acceleration detection unit 614. .

On the other hand, the second acceleration detection unit 614 detects the second acceleration α2 used when the pulldown speed determination unit 640 determines the pulldown speed. The smoothing time width Ta2 of the second acceleration detection unit 614 is set to a relatively narrow time width, specifically, a time width shorter than the smoothing time width Ta1 of the first acceleration detection unit 612. FIG. When the smoothing time width is wide, the signal after the smoothing process has a large response delay from the events and conditions of the driving wheels. Therefore, the second acceleration detection unit 614 performs smoothing processing with a narrow smoothing time width to detect the second acceleration, and the reduction speed determination unit 640 uses this second acceleration to reduce the torque command value. By determining the speed, it is possible to determine an adaptive torque reduction speed that is as close as possible to the immediate events and conditions occurring on the drive shaft (driving wheel).

Adder 603 subtracts reference speed Vm from shaft speed V detected by speed detector 601 and outputs speed difference Vd.
The slip/skid detection unit 620 compares and determines whether or not the first acceleration α1 detected by the first acceleration detection unit 612 is greater than or equal to a predetermined acceleration threshold for considering slip/skid, and the speed difference Vd. It has comparators 623 and 625 for comparing and determining whether or not it is equal to or greater than a predetermined speed difference threshold, which is considered to be slipping, a logical product section 627, and a logical sum section 629, and calculates the first acceleration α1 and the speed difference Vd. is used to detect the occurrence of skidding and a detection signal is output to readhesion control section 680 and pull-down speed determination section 640 . The speed difference threshold of the comparator 625 is set to be larger than the speed difference threshold of the comparator 623, and is provided for safety when the threshold determination by the comparators 621 and 623 does not work. Therefore, when it is determined that the determination by the comparator 621 alone is sufficient for the threshold value determination for the slip/skid detection, the comparators 623 and 625, the logical product section 627, and the logical sum section 629 may be omitted. Alternatively, the comparator 623 and the logical product section 627 may be left, and the comparator 625 and the logical sum section 629 may be omitted.

The pull-down speed determination unit 640 has a minimum pull-down speed, which is the minimum pull-down speed, and a minimum pull-down speed, which is the maximum pull-down speed. and a function setting unit 643 for setting a broad-sense monotonically increasing increasing function, and the second acceleration α2 when the slip/skid is detected by the slip/skid detection unit 620 is used as a reference acceleration to determine the reduction speed of the torque command value. Then, the determined pull-down speed is output to readhesion control section 680 . The minimum and maximum values set by the minimum and maximum value setting unit 641 may be fixed values set in advance, or may be set to 1) the reference speed Vm, 2) the wheel circumference of the driving wheel when the skidding is detected. At least one of the tensile force and 3) the tangential force coefficient equivalent value of the driving wheel may be calculated and set by the above-described functions f _X and f _Y (see FIG. 2).

The wheel circumference tensile force and the tangential force coefficient equivalent value are preferably calculated by the vector arithmetic control device 90 (see FIG. 5) and input to the pull-down speed determination unit 640 of the re-adhesion control device 60. It may be calculated by the adhesion control device 60 .

Any function can be adopted as the function set by the function setting unit 643 as long as it is an increasing function of broad-sense monotone increase (see FIGS. 2 to 4). Since the acceleration of the drive shaft when skidding occurs varies depending on the degree of skidding, the speed of reducing the torque generated by the electric motor 10 is adaptively changed by changing the speed of reduction based on the acceleration. becomes possible.

A recovery detection unit 660 detects recovery from idle sliding to the original sticky running based on the shaft speed V and the speed difference Vd. When the acceleration is used for recovery detection, the acceleration is detected and used by differentiating the axial velocity V and smoothing in the direction of the time axis, or detected by the second acceleration detection unit 614. A second acceleration can be used. When recovery is detected, recovery detection section 660 outputs a recovery detection signal to re-adhesion control section 680 .

Readhesion detection unit 670 detects readhesion based on shaft speed V and speed difference Vd. When the acceleration is used to detect readhesion, the acceleration is detected and used by differentiating the axial velocity V and smoothing in the direction of the time axis, or the second acceleration detection unit 614 A second detected acceleration can be utilized. When readhesion is detected, readhesion detection section 670 outputs a readhesion detection signal to readhesion control section 680 .

As described with reference to FIG. 1 , the readhesion control unit 680 generates a torque reduction command signal for reducing the torque generated by the electric motor 10 to achieve readhesion, and outputs the signal to the vector calculation control device 90 . re-adhesion control. Specifically, when the slip/skid detection signal is input from the slip/skid detection unit 620 , torque reduction control is performed to reduce the torque command value according to the reduction speed input from the reduction speed determination unit 640 . Further, the readhesion control section 680 ends the torque reduction control when the recovery detection signal is input from the recovery detection section 660, and holds the torque reduction amount until the readhesion detection signal is input from the readhesion detection section 670. do. Then, after the re-adhesion detection signal is input, control is performed to gradually restore the torque command value.

As described above, according to the present embodiment, the acceleration of the driving wheel, which is the detection target of slip/skid, is used as the reference speed to adaptively determine the reduction speed for reducing the torque command value when slip/skid is detected. be able to. That is, it is possible to variably determine the speed at which the torque generated by the electric motor is reduced based on the acceleration of the driving wheel that is subject to slip/skid detection. Since the acceleration of the driving wheel when skidding occurs changes depending on the degree of skidding, by changing the reduction speed based on the acceleration, it is possible to adaptively change the speed at which the torque generated by the electric motor is reduced. .

Further, the second acceleration detected using the second smoothing process with a narrow time width for smoothing is used to determine the pull-down speed. When the smoothing time width is wide, the signal after the smoothing process has a large response delay from the events and conditions of the driving wheels. Therefore, by determining the reduction speed of the torque command value using the second acceleration with a narrow smoothing time width, an adaptive torque reduction speed that is in line with the immediate event and situation occurring in the driving wheel as much as possible is determined. It becomes possible to

[Modification]
Although the embodiments to which the present invention is applied have been described above, the embodiments to which the present invention can be applied are not limited to the above-described embodiments. For example, it can be applied not only to electric vehicles but also to electric vehicles. Further, although the slip has been described in detail, similar control can also be applied to sliding.

In the above-described embodiment, referring to FIG. 6, the pull-down speed determination unit 640 determines the pull-down speed when the slip/skid detection signal from the slip/skid detection unit 620 is input, and the re-adhesion control device 60 explained as outputting to This can be done as follows. That is, the pull-down speed determining unit 640 determines the pull-down speed as needed and outputs it to the re-adhesion control device 60 . Then, when the readhesion control device 60 receives a slip/skid detection signal from the slip/skid detection unit 620 , it performs control to reduce the torque command value according to the reduction speed input from the reduction speed determination unit 640 .

In the above-described embodiment, the slip/skid detection unit 620 detects slip/skid using the first acceleration α1. good too. Specifically, as shown in FIG. 7, a slip/skid detection section 620b is configured by adding a comparator 622 and an AND section 626 to the configuration of the slip/skid detection section 620 shown in FIG. A comparator 622 compares and determines whether or not the second acceleration α2 is equal to or greater than a predetermined acceleration threshold value for determining that the vehicle is skidding. 627.

10 electric motor 50 electric motor control device 60 re-adhesion control device 601 speed detector 612 first acceleration detector 614 second acceleration detector 620 slip/skid detector 640 pull-down speed determiner
641 Minimum/maximum setting unit
643 function setting unit 660 recovery detection unit 670 readhesion detection unit 680 readhesion control unit

Claims (6)

Electric motor control that performs torque reduction control to reduce the torque command value of the electric motor that drives the driving wheels when the occurrence of slipping or sliding (hereinafter referred to as "slipping") of the driving wheels is detected to perform re-adhesion control of the driving wheels. a method,
a first acceleration detection step of detecting a first acceleration by performing a differential operation and a first smoothing process of smoothing in the direction of the time axis based on the detected speed of the driving wheel;
Based on the detected speed of the driving wheel, a differential operation and a second smoothing process for smoothing in the direction of the time axis, wherein the smoothing time width is narrower than that of the first smoothing process. a second acceleration detection step of detecting a second acceleration by performing
a slip/skid occurrence detection step of detecting occurrence of slip/skid using the first acceleration;
SaidsecondA reduction speed determination step of determining the reduction speed of the torque command value using the acceleration of as a reference acceleration;
Said glidingDepending on the detection of the occurrence detection stepa torque reduction control step of reducing the torque command value according to the determined reduction speed;
A motor control method comprising: The reduction speed determining step determines the reduction speed of the torque command value according to a given broad-sense monotonically increasing function based on the reference acceleration determined between a given minimum reduction speed and a given maximum reduction speed. is the step of determining
The electric motor control method according to claim 1 . setting the minimum pull-down speed and/or the maximum pull-down speed based on train speed;
3. The motor control method of claim 2 , further comprising: a tensile force detection step of detecting a wheel circumference tensile force of the driving wheel;
setting the minimum pull-down speed and/or the maximum pull-down speed based on the wheel circumference tensile force;
4. The motor control method according to claim 2 or 3 , further comprising: a tangential force coefficient equivalent value detection step of detecting the tangential force coefficient equivalent value of the driving wheel;
setting the minimum pull-down speed and/or the maximum pull-down speed based on the tangential force coefficient equivalent value;
The electric motor control method according to any one of claims 2 to 4 , further comprising Electric motor control for controlling the re-adhesion of the driving wheels by performing torque reduction control to reduce the torque command value of the electric motor that drives the driving wheels when it is detected that the driving wheels are spinning or skidding (hereinafter referred to as "slipping"). a device,
a first acceleration detection unit that detects a first acceleration by performing a differential operation and a first smoothing process for smoothing in the direction of the time axis based on the detected speed of the driving wheel;
Based on the detected speed of the driving wheel, a differential operation and a second smoothing process for smoothing in the direction of the time axis, wherein the smoothing time width is narrower than that of the first smoothing process. a second acceleration detection unit that detects a second acceleration by performing
a slip/skid occurrence detection unit that detects occurrence of slip/skid using the first acceleration;
Saidseconda reduction speed determination unit that determines the reduction speed of the torque command value using the acceleration of as a reference acceleration;
Said glidingDepending on the detection of the occurrence detection unita torque reduction control unit that performs the torque reduction control for reducing the torque command value according to the determined reduction speed;
A motor controller with

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