Abstract: In a method for monitoring an electromagnetically actuable brake, which has an energizable coil that interacts with a tractive electromagnet situated so as to be linearly movable, and a vehicle having an electromagnetically actuable brake, the current flowing through the coil is acquired, the acquired current value in particular being conveyed to an evaluation unit, the voltage applied at the coil is intermittently increased, and a relative position of the tractive electromagnet with respect to the coil is determined from the thereby induced current characteristic, in particular the characteristic of the current rise, it is particularly determined from the ascertained position whether the brake is in the applied state or in the released state, the tractive electromagnet in particular is arranged as a permanent magnet or has a permanent magnet.

Abstract: Techniques for error handling by a servomechanism are disclosed. The servomechanism determines, based on a first set of values assigned to servomechanism variables, electrical signals for controlling a component during a particular time interval, and applies the electrical signals to move the component. Subsequently, the servomechanism measures values for attributes associated with the component. Based on the measured attribute values, the servomechanism computes a second set of values for the servomechanism variables. Responsive to determining that the measured attribute values are erroneous, the servomechanism refrains from modifying the electrical signals based on the second set of values for the servomechanism variables.

Abstract: A method of operating an electromechanical actuator (EMA) system includes determining a command time remaining for an actuator to attain a commanded position and determining a stop time required to stop movement of the actuator. The command time is compared to the stop time, and an electric motor driving the actuator is decelerated if the stop time is equal to or greater than the command time. An electromechanical actuator system includes an actuator and an electric motor operably connected to the actuator, the electric motor configured to drive movement of the actuator. A controller is operably connected to the electric motor to control operation of the actuator. The controller is configured to determine a command time remaining, determine a stop time, compare the command time to the stop time, and decelerate the electric motor if the stop time is equal to or greater than the command time.

Abstract: A braking control method includes steps of: (i) confirming whether to enter a blending section where regenerative braking torque is reduced and friction braking torque is increased; (ii) determining a target reduced deceleration by a controller upon entering the blending section; (iii) reducing braking torque of a vehicle in response to the determined target reduced deceleration; and (iv) returning the braking torque of the vehicle to driver's requested braking torque when the vehicle is being stopped.

Abstract: A numerical controller capable of finely designating a restart condition for look-ahead for a program after suppression of the look-ahead is configured to sequentially read out and analyze commands for blocks of a program, perform look-ahead processing to save the result of the analysis in a buffer, and execute the commands for the blocks looked ahead based on the analysis result saved in the buffer, thereby controlling a machine, and is provided with a function of stopping the look-ahead processing when a block into which a code for stopping look-ahead is inserted is read out from the program.

Abstract: A brake control device of a railcar includes: a brake switching portion configured to perform switching from an operation of an electric brake device to an operation of a mechanical brake device when a switching monitoring speed obtained from a wheelset speed becomes less than a switching threshold; and an adhesion control portion configured to, when the brake switching portion performs the switching, control at least one of the electric brake device and the brake switching portion to cause a wheel to adhere to a rail.

Abstract: A motor driving device includes, a DB current calculation unit which calculates a DB current flowing through a DB circuit, based on the motor rotational speed and intrinsic parameters for a motor and the DB circuit, a Joule heat calculation unit which calculates a Joule heat resulting from a DB current, based on the DB current, a storage unit which stores a table defining the relationship between the DB current at the start of DB and the Joule heat resulting from an arc generated in a relay depending on the DB current, an integration unit which integrates the Joule heat resulting from an arc at the start of DB, the Joule heat resulting from a DB current, or the sum of these Joule heats, every time DB is performed, and a comparison unit which outputs the comparison result between the resultant integration value and a predetermined reference value.

Abstract: A torque control system for a vehicle having a plurality of wheels, wherein at least two of the wheels are arranged to be driven by separate electric motors, the system comprising a master controller arranged to monitor the torque generated by at least one of the electric motors and upon a determination that the torque produced by the at least one electric motor is reduced as a result of a predetermined condition the master controller is arranged to adjust the torque generated in the at least one electric motor and/or another electric motor so that the torque generated by the at least one electric motor and the another electric motor are substantially the same.

Abstract: Device and process for braking rotating and/or slewing gears of work machines comprising at least one dynamic service brake for decelerating a rotating and/or pivotal movement of the rotating and/or slewing gear, and at least one static holding brake (16), by means of which the rotating and/or slewing gear can be locked in one position, wherein at least one sensor (14) is assigned to the dynamic service brake (11a) and/or to the static holding brake (16), said sensor detecting the current movement of the rotating and/or slewing gear, and the sensor (14) being connected to a controller (13, 19) that detects an actuation of the dynamic service brake (11, 11a) said controller actuating the static holding brake (16) when in case of continued rotating and/or pivoting movement of the rotating and/or slewing gear when a dynamic service brake (11a) is still actuated.

Abstract: The present invention relates to a brake control circuit and a motor system. The brake control circuit is used for controlling a motor brake connected to a motor, and comprises a brake control input module and a brake control main module, wherein the brake control input module includes a control signal input unit and N relays connected in parallel to an output end of the control signal input unit, the relays are electrically connected to the brake control main module, and N is an integer greater than or equal to 2.

Abstract: The invention is directed to a method for braking an electric drive motor having a stator and a rotor. The stator has field coils which have electrical phase connections for three motor phases. To generate an electromagnetic rotating field driving the rotor, the phase connections are connected to a supply voltage via switches actuated by a control unit which closes the switches depending on the rotary position of the rotor. To brake a rotating rotor, a braking current is generated by short-circuiting the phase connections. A phase short circuit is switched in between each two phase connections of the field coils with a preset temporal sequence to brake the rotor. The phase connections short-circuited are each selected corresponding to the rotary position of the rotor so that that field coil is short circuited in which the voltage induced by the magnetic field of the rotating rotor passes through its maximum.

Abstract: A swiveling body is installed on a base in a swivelable manner. An electric motor for swiveling swivels the swiveling body. An inverter supplies electric power to the electric motor for swiveling. An obstacle detector detects an obstacle around the base and transmits a detected result to a control unit. When the obstacle detector detects the obstacle, the control unit determines whether or not the obstacle is present within a monitoring region, and when the obstacle is present inside the monitoring region, the control unit stops the electric motor for swiveling. In order to avoid danger, the swiveling operation can be stopped more safely.

Abstract: An integrated power converter includes first and second auxiliary switch modules, and one or more braking switch modules. The first auxiliary switch module is mounted at a first location of a laminated bus bar, and connects a first auxiliary lead with a first power layer and a second power layer of the bus bar. The second auxiliary switch module is mounted at a second location of the bus bar, and connects a second auxiliary lead with the first and second power layers. The braking switch modules are mounted at additional locations of the bus bar, adjacent to the first and second locations. Each braking switch module connects a braking lead with one of the power layers of the bus bar, and with a dual diode module or with the other power layer of the bus bar.

Abstract: The present disclosure relates to a method of controlling an inverter for driving a swing motor, and particularly, maximally generates braking torque of the swing motor upon generation of failure of the inverter by switching on/off a lower-phase switch or an upper-phase switch of the inverter in order to prevent an upper swing body from freely rotating which is generated when a semiconductor switch of the inverter is switched off upon the generation of over-current and over-voltage of the inverter that drives the swing motor, thereby being capable of protecting the inverter, rapidly stopping the upper swing body, and preventing the risk of accidents.

Abstract: The invention relates to a braking apparatus, an electric drive and an elevator system. The braking apparatus comprises an apparatus for dynamic braking, for braking an electric machine with dynamic braking, an input for the control signal of the braking apparatus, and also a controller, for controlling the apparatus for dynamic braking as a response to the aforementioned control signal of the braking apparatus.

Abstract: A control device configured with an external input estimator that reduces a vibration component of a rotational speed of the power transfer system at a rotational speed of the rotary electric machine and estimates transfer system input torque on the basis of the rotational speed of the rotary electric machine, and that estimates external input torque by subtracting at least output torque of the rotary electric machine from the transfer system input torque. A low-vibration speed calculator calculates a low-vibration rotational speed on the basis of the external input torque and vehicle required torque. A rotational speed controller calculates feedback command torque that matches the rotational speed of the rotary electric machine with the low-vibration rotational speed. A torque command value calculator calculates an output torque command value on the basis of the vehicle required torque and the feedback command torque.

Abstract: A control device for a vehicle includes: a charge control portion that adjusts an upper limit of charging power to a battery to prevent a negative electrode potential of the battery from dropping to a lithium reference potential, based on a charge/discharge history of the battery; a braking control portion that detects a sharing ratio between hydraulic braking force by a braking device and regenerative braking force for desired braking force according to a brake pedal depression amount so that a motor generator generates a regenerative braking force within a range of the adjusted upper limit of charging power; and a setting portion that variably sets, according to the hydraulic response rate detected by the detection portion, a degree of limitation of the upper limit when restricting charging current to the battery by restricting the upper limit.

Abstract: A programmable robot system includes a robot provided with a number of individual arm sections, where adjacent sections are interconnected by a joint. The system furthermore includes a controllable drive mechanism provided in at least some of the joints and a control system for controlling the drive. The robot system is furthermore provided with user a interface mechanism including a mechanism for programming the robot system, the user interface mechanism being either provided externally to the robot, as an integral part of the robot or as a combination hereof, and a storage mechanism co-operating with the user interface mechanism and the control system for storing information related to the movement and further operations of the robot and optionally for storing information relating to the surroundings.

Abstract: There is provided a slewing control device that enables to detect breakdown of a driving system of a mechanical brake, and generate a torque for holding a slewing body in a stopped state to thereby prevent movement of the slewing body when an anomaly has occurred. In a working machine for driving a slewing body by an electric motor 1, judgment is made as to whether a mechanical brake 4 is in an inconsistent state, based on a command to be outputted to a brake circuit B, and a pressure detected by a brake pressure sensor 17. The inconsistent state is a state that the mechanical brake 4 is in a brake released state when an activation command for switching the mechanical brake 4 to a brake activated state is outputted. If it is judged that the mechanical brake 4 is in the inconsistent state, a command for obtaining a braking torque for holding the slewing body in a stopped state is outputted to the electric motor 1.

Abstract: An electric motor includes a rotor and a stator. Apart of the rotor includes a first frictional portion forming a movement locus. The stator includes a second frictional portion which brakes and stops the rotation of the rotor by a mechanical frictional force produced by contact between the second frictional portion and the first frictional portion, and a braking actuator which does not allow application of braking by shifting the second frictional portion away from the first frictional portion during power supply to the electric motor, and allows application of braking by pressing the second frictional portion against the first frictional portion during cutoff of power supply to the electric motor.

Abstract: A control system for controlling an industrial robot and a method thereof. A control unit generates a control signal for controlling the motor. At least one drive unit controls the motor. The drive unit includes a switching unit adapted to convert DC current to alternating current to the motor in dependence on the control signal. A safety unit generates a stop signal for stopping the robot upon occurrence of a safety event. The drive unit disables the switching unit upon receiving the stop signal. The safety unit generates the stop signal with a time delay with respect to the safety event. The control unit generates the control signal in such a way that the motor is electrically braked during the time delay.

Abstract: An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

Abstract: A self-tuning vibration absorber including a carrier rod assembly having operatively connected thereto a mounting mechanism for mounting the carrier rod assembly to a primary system and a hollow shafted motorized tuning mechanism for tuning a phase difference between vibration of the primary system and vibration of the carrier rod assembly to 90 degrees, the carrier rod assembly further including a detecting mechanism for detecting the vibration of the primary system and the vibration of the carrier rod assembly, and a controller in electrical connection with the detecting mechanism and the tuning means for controlling the tuning mechanism based on the vibration of the primary system and the vibration of the carrier rod assembly detected. A method of vibration dampening, a method of controlling a self-tuning vibration absorber, and a method of reducing hunting motion in railcars.

Abstract: The present invention relates generally to regenerative braking methods for a hybrid vehicle such as a hybrid locomotive, which are compatible with optimum management of a large battery pack energy storage system. Four methods for recovering energy from regenerative braking and for transferring this energy to an energy storage systems are disclosed. These methods may also be used with battery operated vehicles.

Abstract: In an excavator equipped with an offset boom, an offset command value generating device of a rotation control device offsets a second boom arranged on a distal end side in a rotation direction relative to a first boom arranged on a proximal end side when an acceleration start judging device judges that a rotation operation is started, and offsets the second boom in a reverse rotation direction when a deceleration start judging device judges that a rotation deceleration operation is started. Accordingly, when a rotation acceleration is performed using a reaction force generated in the offset, clearances between members of a work machine can be contracted in advance in the rotation direction, while when the rotation deceleration operation is performed, these clearances can be contracted in advance in the rotation reverse direction, thereby reducing an impact in the acceleration and deceleration.

Abstract: A drive system for a motor vehicle comprising an internal-combustion engine, an electric machine coupled to the internal-combustion engine, and a transmission device through which a ratio change can be implemented without a tractive power interruption is described. Also described is a control device for controlling the electric machine and for controlling the transmission device. The control device is constructed such that, in the event of a braking demand, the demanded total braking torque is at least proportionally provided by the electric machine, and, in the case of an existing braking demand with a constant total braking torque and a change of the transmission ratio implemented in the presence of this braking demand, the electric machine is controlled such that the total braking torque changing because of the ratio change is at least partially compensated, so that a constant total braking torque according to the braking demand is maintained.

Abstract: A dynamic braking load analyzer that determines the proper resistance value for a dynamic braking load resistor to be used in combination with a variable frequency drive or servo-drive to accommodate the power dissipated from an induction motor when it is being reduced in speed. The analyzer includes a resistor bank having a plurality of resistors electrically coupled in parallel. Switches are provided between the resistors, and a resistor selector switch determines which resistors are switched into the resistor bank circuit. A heat sensing resistor in the resistor bank measures the heat generated by the resistors and provides a signal that is read by a heat meter. The combination of the temperature measurement and the resistance of the resistors in the circuit gives the proper braking resistance value for the deceleration of the induction motor.

Abstract: An electric car control apparatus with which it is possible to make the size of equipment small. The control apparatus includes current detectors for respectively detecting currents flowing through collector shoes mounted on a leading car; a no-current indicator for outputting a no-current signal when the currents detected by these current detectors are zero; a no-current train line for transmitting the no-current signal to the following car; and disconnection timer mounted on each of the cars for, when inputting a speed signal and a no-current signal, in correspondence with the speed of the cars outputting a disconnection signal for causing a connector to disconnect after a predetermined time such that it is possible to determine that there is a dead section or gap.

Abstract: To stop, in an emergency, a revolving superstructure quickly from rotating while preventing damage of a mechanical brake. A revolving superstructure is driven swiveling using a permanent magnetic-type swiveling electric motor; in an emergency, such as a malfunction in a drive or control system for the swiveling electric motor, allowing electric power generated in the electric motor due to inertial rotation to be consumed in an external braking resistor so as to make an electric braking action; and a mechanical brake is activated to stop the rotation and hold the stopped revolving superstructure when a rotation speed of the revolving superstructure becomes equal to or lower than a preset value.

Abstract: A braking system for electric step motors that operate in conjunction with a light assembly, including a moving head for pan or tilt thereof or for moving internal optical components. The step motors are connected to driving means to reduce movement speed of the moving head during power down and are connected through switches with a first operating position to connect the driving means to the step motors, and with a second power down position to establish a current path through a motor winding. Movements after power down take place very slowly and without generating noise for use in a theatre where the lamp may be switched off because a fuse burn out, and so cease operation without making disturbing noise. In a controlled power down, noise is reduced when several lamp fixtures placed side by side at the same time move to a stop position.

Abstract: A car control apparatus including a wheel sensor, wheel torque calculating means for calculating wheel torque from the wheel speed, drive force detecting means for detecting drive force generated by an electric motor, car body drive force calculating means for calculating car body drive force from the above drive force and wheel torque, car body drive force fluctuating component extracting means for extracting multiple frequency band fluctuating components of the car body drive force, and drive or braking force control unit for controlling the running state of a car.

Abstract: A drive system with an electric motor is described, which includes an integrated armature short-circuit brake and a mechanical brake. If the electric motor cannot be controllably slowed down, a control signal is applied at an activation time to the integrated armature short-circuit brake and the mechanical brake, and the armature short-circuit brake is switched off when reaching a thermal load limit for the electric motor or the control electronics.

Abstract: A motor has built therein a brake for stopping the rotation of the motor and a brake controlling circuit for controlling the brake. The motor is further provided with a bypass circuit for supplying an electric power directly to the brake and a terminal for connecting a power source to the bypass circuit. When the brake controlling circuit develops a fault, the brake is directly released by an external power source.

Abstract: A traction control system for controlling an electric traction motor drivingly coupled to a wheel of a tractive vehicle. The traction control system includes means for determining speed of the wheel, means for determining tractive effort of the wheel and a control circuitry for controlling drive signals to the motor based upon the wheel speed and tractive effort.

Abstract: A hybrid propulsion system. The system comprises one or more hybrid propulsion traction drives having an electric motor operable to produce mechanical power for propulsion. A hybrid propulsion traction drive is operable to receive power from an on-board power generation system. The electric motor is operable to receive power from an energy storage unit and operable to supply power to the energy storage unit. The energy storage unit may be coupled to the electric motor via a switch.

Abstract: A control apparatus for an electric railcar that provides control so that when rotational speed of a motor decreases below a required value, torque of the motor will decrease at a required rate of change, a current limiter for limiting a torque current command “(A)Iqp” output from a current command arithmetic unit is provided to ensure that when the rotational speed of the motor decreases below the required value, the torque current command will be limited to a command value “(B)Iqp” smaller than that command value, and to ensure that a carrier frequency at which PWM signals are created when switching elements of the electric power converter are controlled by carrier generator is controlled to become lower than a carrier frequency existing when the rotational speed of the motor decreases below the required value.

Abstract: A motor driving apparatus includes a position detector for detecting a rotational position of a motor to output the detection result as a position signal, a frequency comparator for comparing frequencies of continuous periods in the position signal and detecting a reversed state in which the frequency of the signal in the later period is higher than the frequency of the signal in the earlier period, a brake change over unit for selecting a reverse torque brake control which applies reverse torque to the rotor for braking or a short brake control which shorts coils of the motor for braking and instructing the brake control. The brake change over unit changes over the brake control from the reverse torque brake control to the short brake control, when a command signal for applying a reverse torque is output and the frequency comparator detects the reversed state.

Abstract: A method for reducing engine fuel consumption of an electro-motive vehicle during braking, the method including steps for providing an engine for the vehicle, generating primary electric power at a primary electric power generator connected to the engine, generating primary electric power at a secondary electric power generator connected to the engine, operating a plurality of electric traction motors each coupled in driving relationship to a respective one of a plurality of driven wheels to propel the vehicle during motoring operations and to generate electricity upon braking operations of the vehicle, electrically connecting a braking switch between the traction motors and the primary electric power generator, applying braking, closing the braking switch, and transmitting power generated by the traction motors to the primary electric power generator to operate as a motor to rotate the engine and drive the secondary electric power generator to power the auxiliary equipment without fueling the engine.

Abstract: A multi-stage dynamic braking resistor network (23) is provided that includes a plurality of dynamic brake resistors (1a–d) for dissipating, as heat, regenerative energy inputted onto a system bus (17) by a motor or actuator (19), and a plurality of switches (31a–d) for connecting the dynamic brake resistors (1a–d) to and from the system bus (17), respectively. The multi-stage dynamic braking resistor network (23) further includes a control circuit (25) for controlling the switches (31a–d) such that the dynamic brake resistors (1a–d) are connected to and from the system bus (17) on the basis of a predetermined voltage threshold of the system bus and on the basis of a predetermined rotation pattern.

Abstract: In a method of holding a machine element, whose position is directly or indirectly controlled by an electromotive drive in the absence of a self-locking mechanism, the drive is halted and a brake is activated to maintain the machine element in a holding position, without shutting down the drive which remain active. The drive is thus a safe drive constructed to securely prevent a re-starting although an inadvertent shutdown is not preventable.

Abstract: A brake effort monitor for railcar braking systems includes means connected to receive a brake effort request signal and a vehicle speed signal for generating an energy requested signal. Another device is connected to receive a brake effort actual signal and a vehicle speed signal for generating an actual energy signal. There is a mechanism connected to receive the energy requested signal and add it to one of a previous energy requested signal and a predetermined value for generating an energy requested sum signal. A device is connected to receive the actual energy signal and add it to one of a previous actual energy signal and a predetermined value for generating an actual energy sum signal.

Abstract: In a method of holding a machine element, whose position is directly or indirectly controlled by an electromotive drive in the absence of a self-locking mechanism, the drive is halted and shifted into a standby mode while a brake is activated to maintain the machine element in a fixed position. As soon as a holding position of the altered and exceeds a tolerance value, the machine element is stopped by a type of catch control in which the drive is activated again to catch the machine element or load. The drive is thus a safe drive constructed to securely prevent a re-starting although an inadvertent shutdown is not preventable.

Abstract: In a method of holding a machine element, whose position is directly or indirectly controlled by an electromotive drive in the absence of a self-locking mechanism, the drive is halted and a brake is activated to maintain the machine element in a holding position, without shutting down the drive which remain active. The drive is thus a safe drive constructed to securely prevent a re-starting although an inadvertent shutdown is not preventable.

Abstract: Disclosed is an optimized brake method for braking a motor rotating at a high speed. When the motor rotates at the high speed, the present invention reduces the rotation speed of the motor using a mechanical brake method which has a relatively high rate of energy exhaustion, and when the rotation speed of the motor reduces below a predetermined speed, the present invention stops the motor using an electrical brake method. Therefore, since the mechanical brake method is used during the high speed rotation interval, heat occurrence can be prevented, and the electrical brake method is used during the relatively low speed interval so that the motor can be stopped within a short time.

Abstract: In a roller conveyor system for carrying out zone control, a conveyed article can be stopped in an approximately constant position without varying the position where the article is stopped in a desired control zone even if the weight of the article varies. In order to syop the article in a predetermined control zone, such stop control is carried out that a motor is decelerated and stopped in a plurality of braking systems depending on the change in the pulse width of a rotational pulse signal to stop the article with high precision in a predetermined stop position.

Abstract: A sensorless brushless-DC-motor mounted on an electric or hybrid vehicle is powered by an on-board battery through an inverter supplying a three-phase pulse width modulated voltage (PWM voltage). The inverter is controlled to generate the PWM voltage having an average voltage level corresponding to a target motor speed. The PWM voltage level is controlled by changing its duty ratio, so that a difference between the target motor speed and an actual motor speed is minimized. The actual motor speed is determined based on a signal indicating a rotor position detected from the PWM voltage imposed on the motor. When the battery voltage drops and the duty ratio becomes 100%, the target motor speed is temporarily reduced to the level of the actual motor speed. When the battery voltage is recovered and the duty ratio becomes lower than 100%, the target motor speed is gradually increased again to the original level.

Abstract: An electric scooter having batteries concealed below the standing platform in a multipurpose battery pan, an anti-lock brake, a dual suspension, a stow and carry feature, integrated electronics including brake control, throttle control, safety measures and theft protection. The dual suspension scooter includes a chassis; a steering column; a front wheel rotatably mounted on a front axle assembly; a rear wheel rotatably mounted on a rear axle assembly; a front cantilevered suspension mechanism mounted between the steering column and the front axle assembly; and a rear suspension mechanism mounted between the rear end of the chassis and the rear axle assembly.

Abstract: A single cycle positioning system utilizing a DC motor wherein a wide ranging incoming AC supply voltage is rectified and a fixed frequency variable duty cycle pulse width modulation is provided to apply a predetermined rms DC voltage to the motor for a single cycle of operation.

Abstract: A brake release circuit of an electromagnetic brake for locking a motor and an indication circuit for indicating a brake release are coupled together. Both the circuits may be turned on and off by a single switch contact. A motorbrake release device secures space saving and high safety, and is economical.

Abstract: An electric car control apparatus with which it is possible to make the size of equipment small. The control apparatus includes current detectors for respectively detecting currents flowing through collector shoes mounted on a leading car; a no-current indicator for outputting a no-current signal when the currents detected by these current detectors are zero; a no-current train line for transmitting the no-current signal to the following car; and disconnection timer mounted on each of the cars for, when inputting a speed signal and a no-current signal, in correspondence with the speed of the cars outputting a disconnection signal for causing a connector to disconnect after a predetermined time such that it is possible to determine that there is a dead section or gap.