FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See section 10, Rule 13] ELECTRIC VEHICLE CONTROL DEVICE, TRAIN CONTROL SYSTEM, AND GROUND DEVICE; MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3, MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. 2 DESCRIPTION ELECTRIC VEHICLE CONTROL DEVICE, TRAIN CONTROL SYSTEM, AND 5 GROUND DEVICE Field [0001] The present disclosure relates to an electric vehicle control device that provides control to reduce or 10 prevent idling and sliding (hereinafter referred to as “idling-sliding”) of an electric vehicle driven by an electric motor, to a train control system including such an electric vehicle control device, and to a ground device that operates in conjunction with such a train control 15 system. Background [0002] In rainy weather or other similar conditions, an electric vehicle may suffer from idling-sliding due to a 20 lower adhesion coefficient of wheels. When idling-sliding occurs on the electric vehicle, control is performed to reduce or prevent the idling-sliding. The term idling refers to a situation in which adhesion is lost when a driving force is being exerted on the wheel by an electric 25 motor, while the term sliding refers to a situation in which adhesion is lost when a braking force is being exerted on the wheel. Idling-sliding control refers to control to normalize the situation of loss of adhesion. [0003] Non-Patent Literature 1 listed below describes a 30 technique relating to idling-sliding control. Specifically, the idling-sliding control described in Non-Patent Literature 1 first determines whether or not the wheel associated with each axle is in an idling state based on 3 the velocity deviation, the reference axle velocity, the reference acceleration, and each axle acceleration. The velocity deviation is a deviation between a maximum axle velocity and a minimum axle velocity. Then, when it is 5 determined that the wheel is in an idling state, an output electric current command value for driving an induction motor is narrowed in range thereof. Narrowing of the output electric current command value causes torque of the induction motor to be narrowed in range. This leads to re10 adhesion of the wheel that is being in an idling-sliding state. Citation List Non-Patent Literature 15 [0004] Non-Patent Literature 1: Mitsubishi Denki Giho (Mitsubishi Electric Corporation's Technical Journal), Vol. 66, No .4, p. 114 (1992) Summary 20 Technical Problem [0005] The conventional idling-sliding control is adapted to make operations as described above. This idling-sliding control provides improvement in re-adhesion characteristic, which provides sufficient performance and 25 has been used on many occasions. [0006] However, when a review is made of the operations during re-adhesion from a viewpoint of further improvement in re-adhesion characteristic, a problem is found in that the conventional idling-sliding control is performed after 30 detection of occurrence of idling-sliding, so that a lot of time from the beginning of idling-sliding control until the halt thereof. [0007] The present disclosure has been made in view of 4 the foregoing circumstances, and it is an object of the present disclosure to provide an electric vehicle control device capable of shortening the time from the beginning of idling-sliding control until the halt thereof. 5 Solution to Problem [0008] In order to solve the above-mentioned problems and achieve the object, the present disclosure provides an electric vehicle control device including an idling-sliding 10 control unit to control to reduce or prevent idling and sliding to which a wheel of an electric vehicle can be subjected, wherein the idling-sliding control unit comprises: an idling-sliding detection unit to detect idling or sliding that has occurred on the electric vehicle, 15 based on rotational velocity of one or more electric motors by which the electric vehicle is driven; and a torque command value generation unit to generate a torque command value used to reduce or prevent the idling or sliding, based on output from the idling-sliding detection unit, and 20 when a prediction signal representing an anticipated occurrence of idling or sliding is inputted, the torque command value generation unit performs narrowing of the torque command value regardless of whether or not the idling-sliding control unit is performing idling-sliding 25 control. Advantageous Effects of Invention [0009] An electric vehicle control device according to the present disclosure provides an advantageous effect that 30 it can shorten the time from the beginning of idlingsliding control to the end thereof. Brief Description of Drawings 5 [0010] FIG. 1 is a diagram schematically illustrating a configuration of an electric vehicle including an electric vehicle control device according to a first embodiment. 5 FIG. 2 is a block diagram illustrating a configuration of the idling-sliding control unit illustrated in FIG. 1. FIG. 3 is a block diagram illustrating a configuration of the idling-sliding detection unit illustrated in FIG. 2. FIG. 4 is a time chart illustrating operation 10 waveforms of a main part in re-adhesion control during idling, of the idling-sliding control unit 2 according to the first embodiment. FIG. 5 is a diagram for describing an operation of a torque command value narrowing unit in the first embodiment. 15 FIG. 6 is a block diagram illustrating an example of a hardware configuration for implementing functionality of the idling-sliding control unit according to the first embodiment. FIG. 7 is a block diagram illustrating another example 20 of a hardware configuration for implementing functionality of the idling-sliding control unit according to the first embodiment. FIG. 8 is a diagram illustrating an example configuration of a train control system according to a 25 second embodiment. FIG. 9 is a flowchart for describing an operation of the train control system according to the second embodiment. FIG. 10 is a first diagram for describing an operation of a train control system according to a third embodiment. 30 FIG. 11 is a second diagram for describing the operation of the train control system according to the third embodiment. FIG. 12 is a block diagram illustrating an example 6 configuration of a ground device according to a fourth embodiment. FIG. 13 is a flowchart for describing an operation of the ground device according to the fourth embodiment. 5 FIG. 14 is a block diagram illustrating an example configuration of a ground device according to a fifth embodiment. FIG. 15 is a flowchart for describing an operation of the ground device according to the fifth embodiment. 10 Description of Embodiments [0011] An electric vehicle control device, a train control system, and a ground device according to embodiments of the present disclosure will be described in 15 detail below with reference to the accompanying drawings. [0012] First Embodiment. FIG. 1 is a diagram schematically illustrating a configuration of an electric vehicle 100 including an electric vehicle control device (hereinafter referred to 20 simply as “control device”) 1 according to a first embodiment. In FIG. 1, the electric vehicle 100 includes four electric motors 5A to 5D for driving the electric vehicle 100. The control device 1 controls the four motors 5A to 5D. Note that FIG. 1 illustrates just a typical 25 exemplary configuration although an alternative configuration can be adopted such that a single control device 1 controls a single motor, or another alternative configuration can be adopted such that a single control device 1 controls multiple motors when the number of motors 30 is other than four. [0013] The motors 5A to 5D are coupled to wheels 6A to 6D, respectively. The motor 5A drives the wheel 6A. The motor 5B drives the wheel 6B. The motor 5C drives the 7 wheel 6C. The motor 5D drives the wheel 6D. Rotation of the wheels 6A to 6D provides the electric vehicle 100 with propulsion force based on frictional force occurring between the wheels 6A to 6D and a rail 7. 5 [0014] The control device 1 according to the first embodiment provides idling-sliding control that is control for reducing or preventing idling and sliding that may occur on the wheels 6A to 6D of the electric vehicle 100. In order to realize this functionality, the control device 10 1 includes an idling-sliding control unit 2, a gate command generation unit 3, and a power converter 4. [0015] In FIG. 1, the idling-sliding control unit 2 receives velocity signals fm1 to fm4 that represent rotational velocities of the wheels 6A to 6D, from the 15 wheels 6A to 6D, respectively. The idling-sliding control unit 2 provides control of torque to prevent idling-sliding of the electric vehicle 100, based on the velocity signals fm1 to fm4 received. The velocity signals fm1 to fm4 are detected on the respective wheels 6A to 6D by sensors 20 attached to the axles (not illustrated). Note that the velocity signals fm1 to fm4 may each be obtained using a main motor velocity obtained by computation using a main motor current that is an electric current flowing through each of the motors 5A to 5D. 25 [0016] A configuration and an operation of a main part of idling-sliding control provided by the control device 1 will next be described. Note that the following description uses notation of “motor 5” or “motors 5” without a suffix when no distinction is made between the 30 motors 5A to 5D, and uses notation of “wheel 6” or “wheels 6” without a suffix when no distinction is made between the wheels 6A to 6D. This manner of notation also applies to other components described below that are distinguished by 8 a suffix. In addition, the following description is provided for a case of idling as a typical example, but description similar thereto can be presented for a case of sliding, needless to say. 5 [0017] The idling-sliding control unit 2 receives, as its inputs, a torque command value Tr, a prediction signal Cs, and a train velocity Vt in addition to the velocity signals fm1 to fm4. The torque command value Tr is a torque command value in a non-idling state. The prediction 10 signal Cs is a signal representing an anticipated occurrence of idling or sliding. The prediction signal Cs is outputted when it is determined that the electric vehicle 100 is about to pass a spot where idling or sliding is more likely to occur. The train velocity Vt is 15 information about a traveling speed including the electric vehicle 100. The prediction signal Cs and the train velocity Vt are inputted from an upper level control device not illustrated in FIG. 1. Note that the prediction signal Cs and the train velocity Vt may be generated inside the 20 control device 1 with use of at least one of an information set transmitted to the control device 1 and an information set generated or computed by the control device 1. [0018] The idling-sliding control unit 2 computes a torque command value Tq based on the velocity signals fm1 25 to fm4, the torque command value Tr, the prediction signal Cs, and the train velocity Vt. [0019] The gate command generation unit 3 receives, as its input, the torque command value Tq generated by the idling-sliding control unit 2. The gate command generation 30 unit 3 generates a gate command G based on the torque command value Tq. The gate command generation unit 3 has a concept of including a torque computing unit, a current command value computing unit, a voltage command value 9 computing unit, and the like. These units can be configured using a publicly known technique. [0020] The power converter 4 is controlled based on the gate command G to generate driving power for driving the 5 motors 5. The driving power generated by the power converter 4 is supplied to one or more of the motors 5. This causes a single motor to be driven or multiple ones of the motors 5 to be collectively driven. [0021] FIG. 2 is a block diagram illustrating a 10 configuration of the idling-sliding control unit 2 illustrated in FIG. 1. As illustrated in FIG. 2, the idling-sliding control unit 2 includes an idling-sliding detection unit 8 and a torque command value generation unit 9. The torque command value generation unit 9 includes 15 adhesion status estimators 101 to 104, a torque command level setter 11, a selection switch 12, a 1st delay system 13, and a torque command value narrowing unit 14. [0022] The idling-sliding detection unit 8 determines the adhesion status of each of the wheels 6 on the basis of 20 the velocity signals fm1 to fm4 of the wheels 6, the torque command value Tr in a non-idling state, and a torque command value Tp (described later) generated by the 1st delay system 13. [0023] The adhesion status estimators 10 output 25 coefficients g1 to g4 each of which represents the adhesion status of the corresponding one of the wheels 6, based on velocity deviations ΔV1 to ΔV4 and acceleration deviations Δα1 to Δα4, where the velocity deviations ΔV1 to ΔV4 are each a deviation between the velocity of each of the wheels 30 6 and a reference velocity, and the acceleration deviations Δα1 to Δα4 are each a deviation between the acceleration of each of the wheels 6 and a reference acceleration. As the reference velocity, the minimum value of velocity of each 10 of the wheels 6 is selected. The reference acceleration is an acceleration of the wheel 6 corresponding to the reference velocity. Note that as the reference velocity, vehicle velocity information transmitted from an upper 5 level control device (not illustrated in FIG. 1) may be used. [0024] The torque command level setter 11 computes a torque command level Ta using Equation (1) shown below based on the coefficients g1 to g4 and the torque command 10 value Tr in a non-idling state. [0025] Ta=Tr×(g1+g2+g3+g4)/4 … (1) [0026] The selection switch 12 selects any one of the torque command level Ta and the torque command value Tr in a non-idling state, on the basis of a control signal CSW 15 outputted from the idling-sliding detection unit 8. The output of the selection switch 12 is inputted to the 1st delay system 13 as a torque command level Ti. [0027] The 1st delay system 13 is a controller having a time element of a time constant tc. The 1st delay system 20 13 generates the torque command value Tp based on the torque command level Ti outputted from the selection switch 12. The value of the time constant tc is changed based on the torque command level Ti. A specific example is as follows. Note that it is assumed that the 1st delay system 25 13 is configured to enable two time constants ts and tl satisfying a relationship of ts