JP6885698B2 - Fault diagnostic equipment, methods, programs and electric mobiles - Google Patents

Description

The present invention relates to a technique for diagnosing a failure of an emergency stop switch for diagnosing the presence or absence of a failure of a switch such as a protective relay interposed between a power supply and an electric load unit.

Conventionally, in a power supply device that supplies electric power to a vehicle motor to perform traveling, a power supply device in which a plurality of relays connected in series that function as an emergency stop are interposed between the power supply device and the motor has been proposed. In this type of power supply device, failure diagnosis of the relay is performed in consideration of the function of the relay for emergency stop. According to Patent Document 1, when performing a failure diagnosis of two relays during startup initialization when the power is turned on, the state of charge of the capacitors connected in parallel to the motor is detected, and the failure diagnosis is made according to the presence or absence of the state of charge. It is described that the relay is opened and closed by switching the method, so that an appropriate relay diagnosis can be performed in a short time.

JP-A-2009-259762

However, in the power supply device described in Patent Document 1, since there is a period in which both relays are turned on at the same time during the failure diagnosis sequence, power is supplied to the motor during that period, and the vehicle may start running carelessly. , There is a risk of runaway. On the other hand, in such a failure diagnosis method, the vehicle is put into a running drive state to perform a failure diagnosis of the relay, and it is considered that there is room for improvement in the failure diagnosis method in terms of product quality.

The present invention has been made in view of the above problems, and is a device, a method, a program, and a failure diagnosis for performing a failure diagnosis of an emergency stop switch that enables a failure diagnosis of a switch without supplying electric power to an electric load unit. It is an object of the present invention to provide an electric moving body equipped with a device.

The failure diagnosis device for an emergency stop switch according to the present invention is a plurality of switches on the load side connected in series between a power source and an electric load unit driven by receiving power from the power source. In the failure diagnosis device of the emergency stop switch that performs the failure diagnosis process, the voltage detection unit that detects each output end voltage of the plurality of switches on the load side and the power supply side for each preset monitoring period. Outputs a changeover signal that turns off all switches in the first monitoring period, and a changeover signal that selectively turns on in the second and subsequent monitoring periods, from the first switch to the switches other than the last switch. It is provided with a diagnosis execution unit that detects each output end voltage in each monitoring period, and a diagnosis result processing unit that performs failure diagnosis of each switch from each output end voltage in each monitoring period.

Further, the method for diagnosing an emergency stop switch according to the present invention is a plurality of load-side connections connected in series between a power supply and an electric load unit driven by receiving power from the power supply. In the emergency stop switch failure diagnosis method for performing the switch failure diagnosis process, the voltage detection unit that detects each output end voltage of the plurality of switches on the load side is used, and the above-mentioned is performed every preset monitoring period. For the switches from the first switch on the power supply side to the switches other than the last switch, the changeover signal that turns off all the switches in the first monitoring period is selectively turned on in the second and subsequent monitoring periods. It includes a diagnosis execution step that outputs a switching signal and detects each output end voltage in each monitoring period, and a diagnosis result processing step that performs a failure diagnosis of each switch from each output end voltage in each monitoring period. Is.

Further, the failure diagnosis program according to the present invention is used for failure diagnosis of a plurality of switches on the load side connected in series between a power source and an electric load unit driven by receiving power from the power source. In a failure diagnosis program that causes a failure diagnosis device to perform processing, a voltage detection unit that detects each output end voltage of a plurality of switches on the load side is used, and the head of the power supply side is set for each preset monitoring period. Outputs a changeover signal that turns off all switches in the first monitoring period, and a changeover signal that selectively turns on in the second and subsequent monitoring periods from the switch of The failure diagnosis device functions as a diagnosis execution means for detecting each output end voltage in each monitoring period, and a diagnosis result processing means for performing failure diagnosis of each switch from each output end voltage in each monitoring period. is there.

According to such an invention, when diagnosing a failure of a switch such as a relay interposed between a power source and an electric load unit, a procedure of supplying electric power from the power source to the electric load unit is not adopted, so that the electric moving body can be used. Careless movement or runaway can be suppressed, and the reliability of failure diagnosis processing can be improved.

Further, the plurality of switches on the load side are first and second switches, and the diagnosis execution unit outputs a changeover signal for turning on only the first switch in the second monitoring period, and outputs each output. The end voltage is detected, and the diagnosis result processing unit diagnoses from each output end voltage whether or not the first and second switches are in a constantly conducting state during the first monitoring period, and the second During the monitoring period of, it is diagnosed whether or not the first switch is in a constantly shut-off state. According to this configuration, the failure diagnosis of the first and second switches is performed using the first and second monitoring periods. In particular, since it is possible to diagnose whether or not the failure is in the constantly conducting state of the first and second switches, it is possible to diagnose a severe failure.

Further, the diagnosis execution unit provides a third monitoring period for outputting a switching signal for turning on only the second switch, detects each output end voltage during the third monitoring period, and performs the diagnosis result processing unit. Diagnoses the presence or absence of an abnormality on the output line of the switching signal to the first and second switches. According to this configuration, it is possible to diagnose the presence or absence of the signal lines around the first and second switches, and the reliability is further improved.

Further, the diagnosis execution unit makes the time from the start of the second monitoring period to the detection of the output end voltage shorter than the time from the start of the third monitoring period to the detection of the output end voltage. The feature is that it has been set. According to this configuration, by shortening the time from the start of the second monitoring period to the detection of the output terminal voltage, even if the second switch is short-circuited (failed), the current flowing into the electric load section can be reduced. It is suppressed (risk can be reduced).

Further, the present invention is provided with a protection circuit interposed between the power supply and the first switch to interrupt the circuit by receiving an abnormal signal from the diagnosis result processing unit, and the diagnosis result processing unit is the diagnosis result processing unit. When the first and second switches are diagnosed as having a failure in a constantly energized state, the abnormal signal is output to the protection circuit. According to this configuration, when both the first and second switches are in a continuous conductive state, the power supply and the electric load unit are short-circuited, so that the short-circuit can be interrupted by the protection circuit. This makes it more reliable.

Further, the present invention is characterized in that the power source is provided with a braking unit that causes a braking force to act on the drive of the electric load unit when power is not supplied and releases the braking force when power is supplied. According to this configuration, the braking unit exerts a braking force on the electric load unit when no power is supplied, so even if a current accidentally flows through the electric load unit when diagnosing a failure of a plurality of switches on the electric load side, the electric load is applied. The part does not run away.

Further, the present invention includes a plurality of switches on the braking side connected in series between the braking unit and the power supply, and the monitoring execution unit and the diagnosis result processing unit are on the electric load side. After executing the failure diagnosis for the plurality of switches, the failure diagnosis for the plurality of switches on the braking unit side is executed. According to this configuration, the electric load unit does not accidentally run out of control when diagnosing a failure on the electric load side.

Further, the present invention provides an electric mobile body including a power source, an electric load unit driven by receiving power supplied from the power source, and a failure diagnosis device for an emergency stop switch. According to this configuration, a highly reliable electric moving body is provided.

According to the present invention, it is possible to perform a failure diagnosis of an emergency stop switch without supplying electric power to the electric load unit.

It is a figure which shows the schematic structure of the electric moving body to which the failure diagnosis apparatus of the emergency stop switch which concerns on this invention is applied. It is a circuit diagram around the power relay circuit part for emergency stop which concerns on 1st Embodiment. It is a block diagram of the diagnostic control part which concerns on 1st Embodiment. It is a time chart which shows the sequence of failure diagnosis which concerns on 1st Embodiment. It is a circuit diagram around the power relay circuit part for emergency stop which concerns on 2nd Embodiment. It is a block diagram of the diagnostic control part which concerns on 2nd Embodiment. It is a circuit diagram around the power relay circuit part for emergency stop which concerns on 3rd Embodiment. It is a block diagram of the diagnostic control part which concerns on 3rd Embodiment. It is a time chart which shows the sequence of failure diagnosis which concerns on 3rd Embodiment. It is a block diagram of the diagnostic control part which concerns on 4th Embodiment. It is a time chart which shows the sequence of failure diagnosis which concerns on 4th Embodiment.

As shown in FIG. 1, the electric moving body 1 has a vehicle body 10 and a pair of wheels 11 supported at lower positions on both the left and right sides in front of and behind the vehicle body 10, and can travel on a flat ground. The electric mobile body 1 can be applied to various traveling bodies, and may be, for example, an autonomous traveling robot whose traveling is controlled by a computer. Further, the electric moving body 1 receives a battery 12 as a power source for supplying electric power at a set voltage, and a motor 17 as an electric load unit for rotationally driving the wheels 11 on the front side of the vehicle body 10 by receiving electric power from the battery 12. It has. Further, if necessary (for example, the third embodiment described later), an electromagnetic brake 18 (indicated by a broken line) that receives power from the battery 12 to apply or release a braking force to the rotation of the motor 17. It has.

Further, as a control system, the electric moving body 1 is a running control that outputs a rotation signal to the emergency stop power relay circuit unit 13, the diagnostic control unit 14 that performs failure diagnosis of the emergency stop power relay circuit unit 13, and the motor 17. A unit 15 and a higher-level control unit 16 that collectively or autonomously controls, for example, the entire traveling sequence and outputs a traveling instruction content to the traveling control unit 15 as required are provided.

Hereinafter, the configurations and operations of the first to fourth embodiments relating to the failure diagnosis device of the emergency stop switch will be described.

(First Embodiment)
The first embodiment will be described with reference to FIGS. 2 to 4. In the first embodiment, the load lines of the battery 12 to the motor 17 are provided, and no protection circuit is provided. Further, the time from the start of each monitoring period to the start of the monitoring operation is set to a normal time, that is, Δt.

In FIG. 2, the emergency stop power relay circuit unit 13 includes a load line from the battery 12 to the motor 17 connected in parallel. The electromagnetic brake 18 is not provided in the first embodiment.

Relays La and Lb connected in series are interposed on the load line from the battery 12 to the motor 17. The relays La and Lb are individually switched between conduction (on) and cutoff (off) by applying an on / off signal (indicated by a broken line in FIG. 2) from the diagnostic control unit 14 to the exciting coil (not shown). I do. Instead of the electromagnetic relays La and Lb, a switch such as a mechanical switch or a semiconductor switch element may be applied. Further, the capacitor C1 is for smoothing the motor 17.

Voltage detection circuits 141 and 142 are connected to the output ends of the relays La and Lb. The voltage detection circuit 141 detects the voltage V1 at the output end of the relay La, and the voltage detection circuit 142 detects the voltage V2 at the output end of the relay Lb. In the first embodiment, the voltage detection circuits 141 and 142 include an AD converter, convert the detected voltage into a digital value, and guide the voltage detection circuit to the diagnostic control unit 14. Although the voltage detection circuits 141 and 142 detect the voltage at the output end with the ground, they may also detect the voltage at the output end with the corresponding input end.

FIG. 3 is a block diagram of the diagnostic control unit 14, and in the first embodiment, a computer is included and a part of the diagnostic processing is performed by software. The function of the diagnostic control unit 14 may be executed by the sequence circuit.

The diagnostic control unit 14 shown in FIG. 3 includes a processing unit 145 composed of, for example, a microcomputer. The processing unit 145 is connected to a storage unit 146 that stores a failure diagnosis sequence program, voltage detection circuits 141 and 142, and exciting coils (not shown) of relays La and Lb.

The processing unit 145 functions as a diagnosis execution unit 1451, a diagnosis result processing unit 1452, and a timer 1453 by executing the failure diagnosis sequence program.

The diagnosis execution unit 1451 executes a failure diagnosis sequence, and as shown in FIG. 4, for example, as shown in FIG. 4, the load line relays La, Lb are set in preset monitoring periods To, Ta, and Tb, for example, as a constant normal period. A switching signal is output to turn off and turn on one by one, and the voltages V1 and V2 are measured during that time. As will be described with reference to FIG. 4, the diagnosis execution unit 1451 performs constant monitoring after each monitoring period is completed and the operation is started. The voltages V1 and V2 are measured when a certain time Δt (monitoring start time) has elapsed from the start time of the monitoring period.

The diagnosis result processing unit 1452 diagnoses the failure of the relays La and Lb from the voltages V1 and V2 measured during the monitoring period To, Ta and Tb. The timer 1453 measures (timekeeps) the monitoring period and the like after the power is turned on.

Next, the failure diagnosis operation will be described using the time chart of FIG. The relay failure includes a failure in a constantly conducting state and a failure in a constantly interrupted state, and the subsequent failure diagnosis diagnoses whether one of these is applicable or the normal condition is not applicable to either of them. It should be noted that, among the failures, the failure in the constantly cut-off state does not cause the motor 17 to rotate carelessly because the current does not flow, and it can be said that the failure is a minor failure as compared with the serious failure in the constantly conducting state.

When the power is turned on, the monitoring period To is first started. During the monitoring period To, an off signal is output to the relays La and Lb. At this time, if the relay La is not in a constantly conducting state, the voltage V1 is both at 0 level (low level). Further, if neither of the relays La and Lb is in a continuous conduction state, the voltages V1 and V2 are both at 0 level (low level).

On the other hand, when only the voltage V1 has a voltage level (high level) corresponding to the voltage of the battery 12 (indicated by the broken line V1o'of the voltage V1 in FIG. 4), it can be seen that the relay La is a failure in a constantly conducting state. In this case, an abnormal signal for notification indicating a failure of the relay La is output, and the subsequent monitoring operation is stopped.

Further, when the voltages V1 and V2 are both at high levels (indicated by the broken line V1o'of the voltage V1 and the broken line V2o'of the voltage V2 in FIG. 4), it can be seen that both the relays La and Lb are always in a conductive state. .. In this case, since the current flows from the battery 12 to the load line, an abnormal signal is output and the subsequent monitoring operation is stopped. Further, in this case, a current temporarily flows from the battery 12 to the motor 17, but the abnormal operation can be stopped by turning off the power automatically or manually. The monitoring start time (voltage detection time point) from the start of each monitoring period is set to a substantially intermediate position (see Δt in FIG. 4) of the monitoring period from the viewpoint of detection accuracy and early detection. Further, when an abnormal signal is output as a diagnosis result, it may be output to the notification unit.

If it is diagnosed in the monitoring period To that the relay La is not a failure in the continuous conduction state, the monitoring operation proceeds to the monitoring period Ta. During the monitoring period Ta, an on signal is output to the relay La and an off signal is output to the relay Lb. At this time, if the voltage V1 is at a high level (indicated by V1a of the voltage V1 in FIG. 4), it is diagnosed that the relay La is not a failure in the constantly cut-off state. That is, the relay La is diagnosed as normal.

Further, when the voltage V2 is also at a high level (indicated by V1a of the voltage V1 in FIG. 4 and the broken line V2a'of the voltage V2), the relay Lb is diagnosed as a failure in the continuous conduction state, and an abnormal signal is output. On the other hand, when the voltage V1 is at a low level, the relay La is diagnosed as a failure in a constantly cut-off state.

Then, in the monitoring period Ta, when it is diagnosed that the relay La is normal and the relay Lb is not a failure in the constantly conducting state, the monitoring operation proceeds to the monitoring period Tb. During the monitoring period Tb, an off signal is output to the relay La, and an on signal is output to the relay Lb. At this time, if the voltages V1 and V2 are both at low levels, it is diagnosed that the on / off signals from the diagnostic control unit 14 to the relays La and Lb are normally output to the corresponding relays. On the other hand, the voltage V1 of the relay La, which has already been determined to be normal, becomes a high level, or the voltage V2 becomes a high level (the broken line V1b'of the voltage V1 and the broken line V2b'of the voltage V2 in FIG. ), Not due to a failure of the relay Lb, but diagnosed as a problem on the power supply line, for example, the presence or absence of erroneous wiring contact. As described above, the monitoring period Tb is not always necessary for the failure diagnosis of the relays La and Lb.

When the monitoring period Tb ends and the start timing shifts, both the relays La and Lb are switched on and the motor 17 is rotationally driven. During this time, the diagnostic control unit 14 monitors the state of the relays La and Lb, at least the state of the relay Lb, and whether or not the voltage V2 is at a low level while the on signal is output to the relays La and Lb. Is detected. When the voltage V2 is at a low level, the relay Lb is notified as a failure in a constantly cut-off state, and the operation of the electric moving body 1 is stopped. On the other hand, if the voltage V2 is at a high level, the relay Lb is normal and the traveling operation is continued.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 5, 6 and 4. In the second embodiment, the load lines of the battery 12 to the motor 17 are provided, and a protection circuit is further provided. Each monitoring start time is set to a normal time, that is, Δt. The description of common parts will be omitted.

FIG. 5 differs from FIG. 2 in that a protection circuit 131 is interposed between the battery 12 and the relay La. The protection circuit 131 is a fuse in this embodiment. A relay Lx is further connected to the output end side of the protection circuit 131. The relay Lx is turned on when an abnormal signal from the diagnostic control unit 14 is received. By this turning on, the relay Lx is short-circuited with the battery 12 and a large current is passed from the battery 12 to the protection circuit 131 to blow the fuse. The blown fuse cuts off the battery 12 from the load line. In addition, instead of the fuse, a polyswitch manufactured from a conductive polymer or the like and which can be used repeatedly may be adopted, and a temporary blocking function may be exhibited by tripping. Further, depending on the traveling state of the electric mobile body 1, an overvoltage caused by regenerative power generation in the motor 17 may be applied to the relays La and Lb to cause a failure, so that the protection circuit 131 may be operated.

FIG. 6 is a block diagram of the diagnostic control unit 14, and in the present embodiment, a computer is included and a part of the diagnostic processing is performed by software. The function of the diagnostic control unit 14 may be executed by the sequence circuit.

The diagnostic control unit 14 shown in FIG. 6 includes, for example, a processing unit 145 composed of a microcomputer, and the processing unit 145 includes a storage unit 146 that stores a failure diagnosis sequence program, voltage detection circuits 141, 142, and relay La. It is connected to the exciting coils (not shown) of Lb and Lx.

The processing unit 145 functions as a diagnosis execution unit 1451, a diagnosis result processing unit 1452, a timer 1453, and a protection processing unit 1454 by executing the failure diagnosis sequence program.

The diagnosis execution unit 1451 executes a failure diagnosis sequence. For example, as in FIG. 4, the relays La, Lb on the load line side are set in advance for example, during a monitoring period To, Ta, Tb as a fixed normal period. A switching signal is output to turn off and turn on one by one, and the voltages V1 and V2 are measured during that time. As in FIG. 4, the diagnosis execution unit 1451 performs constant monitoring after each monitoring period is completed and the operation is started. The voltages V1 and V2 are measured when a certain time Δt (monitoring start time) has elapsed from the start of the monitoring period.

The diagnosis result processing unit 1452 diagnoses the failure of the relays La and Lb from the voltages V1 and V2 measured during the monitoring period To, Ta and Tb. The protection processing unit 1454 outputs an abnormal signal to the relay Lx in order to disconnect the battery 12 from the load line. The timer 1453 measures each monitoring period and the like after the power is turned on.

The failure diagnosis operation in the second embodiment is the same as the time chart of FIG. 4, and only the operation with respect to the protection circuit 131 is different.

When the voltages V1 and V2 are both at high levels during the monitoring period To (indicated by the broken line V1o'of the voltage V1 and the broken line V2o'of the voltage V2 in FIG. 4), both the relays La and Lb are always in a conductive state. You can see that. In this case, since the current flows from the battery 12 to the load line, an abnormal signal for blowing the fuse is output to the relay Lx. Further, in this case, a current temporarily flows from the battery 12 to the motor 17, but the fuse is blown, so that the abnormal operation is stopped. When an abnormal signal for notification or fuse blowing is output as a diagnosis result, it may be output to the notification unit.

If it is diagnosed in the monitoring period To that the relay La is not a failure in the continuous conduction state, the monitoring operation proceeds to the monitoring period Ta. During the monitoring period Ta, an on signal is output to the relay La and an off signal is output to the relay Lb. At this time, when the voltages V1 and V2 are at a high level (indicated by V1a of the voltage V1 in FIG. 4 and the broken line V2a'of the voltage V2), the relay Lb is diagnosed as having a failure in the continuous conduction state, and the fuse blows to the relay Lx. Abnormal signal is output. On the other hand, when the voltage V1 is at a low level, the relay La is diagnosed as a failure in a constantly cut-off state.

Then, in the monitoring period Ta, when it is diagnosed that the relay La is normal and the relay Lb is not a failure in the constantly conducting state, the monitoring operation proceeds to the monitoring period Tb. During the monitoring period Tb, it is diagnosed as a problem on the power supply line, for example, the presence or absence of erroneous wiring contact. As described above, the monitoring period Tb is not always necessary for the failure diagnosis of the relays La and Lb. Further, after the start timing, the relay Lb is diagnosed.

(Third Embodiment)
The third embodiment will be described with reference to FIGS. 7 to 9. In the third embodiment, the load line of the battery 12 to the motor 17 and the braking line of the battery 12 to the electromagnetic brake 18 are provided, and no protection circuit is provided. Further, each monitoring start time is a normal time, that is, Δt. The description of common parts will be omitted.

FIG. 7 differs from FIG. 2 in that it is provided with a braking line. That is, the emergency stop power relay circuit unit 13 includes a load line between the battery 12 and the motor 17 and a braking line between the battery 12 and the electromagnetic brake 18 which are connected in parallel. The electromagnetic brake 18 has a configuration in which a braking force is mechanically applied to the motor 17. In the present embodiment, the braking force acts while the power is not supplied, and when the power is supplied, the braking force is applied. The non-excited brake control type is adopted. Further, the load line and the braking line may be connected in parallel to the battery 12, but the batteries may be provided individually to form a separate circuit.

Relays Lc and Ld connected in series are interposed on the braking line between the battery 12 and the electromagnetic brake 18. The relays Lc and Ld are individually switched between conduction (on) and cutoff (off) by applying an on / off signal (indicated by a broken line in FIG. 7) from the diagnostic control unit 14 to the exciting coil (not shown). I do. Instead of the electromagnetic relays Lc and Ld, a switch such as a mechanical switch or a semiconductor switch element may be applied.

Voltage detection circuits 143 and 144 are connected to the output ends of the relays Lc and Ld. The voltage detection circuit 143 detects the voltage V3 at the output end of the relay Lc, and the voltage detection circuit 144 detects the voltage V4 at the output end of the relay Ld. In the present embodiment, the voltage detection circuits 143 and 144 include an AD converter, convert the detection voltage into a digital value, and guide the detection voltage to the diagnostic control unit 14. Although the voltage detection circuits 143 and 144 detect the voltage at the output end with the ground, they may also detect the voltage at the output end with the corresponding input end.

FIG. 8 is a block diagram of the diagnostic control unit 14, and in the present embodiment, a computer is included and a part of the diagnostic processing is performed by software. The function of the diagnostic control unit 14 may be executed by the sequence circuit.

The diagnostic control unit 14 shown in FIG. 8 includes a processing unit 145 composed of, for example, a microcomputer. The processing unit 145 is connected to a storage unit 146 that stores a failure diagnosis sequence program, voltage detection circuits 141 to 144, and exciting coils (not shown) of relays La to Ld.

The processing unit 145 functions as a diagnosis execution unit 1451, a diagnosis result processing unit 1452, and a timer 1453 by executing the failure diagnosis sequence program.

The diagnosis execution unit 1451 executes a failure diagnosis sequence. For example, as shown in FIG. 9, the relay La on the load line side has a monitoring period To, Ta, Tb as a predetermined normal period, for example, as shown in FIG. A switching signal for turning off Lb and turning it on one by one is output, and the voltages V1 and V2 are measured during that time. Further, in synchronization with the relays La and Lb, a failure diagnosis sequence is executed in which the relays Lc and Ld are similarly turned off and turned on one by one. As will be described with reference to FIG. 9, the diagnosis execution unit 1451 performs constant monitoring after each monitoring period ends and the operation is started.

The diagnosis result processing unit 1452 diagnoses the failure of the relays La and Lb from the voltages V1 and V2 measured during the monitoring period To, Ta and Tb. Similarly, failure diagnosis of relays Lc and Ld is performed. The timer 1453 measures each monitoring period and the like after the power is turned on.

Next, the failure diagnosis operation will be described using the time chart of FIG. Since the failure diagnosis operation of the relays La and Lb shown in FIG. 9 is the same as that of FIG. 4, the description thereof will be omitted, and the part related to the failure diagnosis of the relays Lc and Ld will be described.

First, during the monitoring period To, the diagnostic control unit 14 outputs an off signal to the relays Lc and Ld, and outputs an off signal to the relays La and Lb.

At this time, when the voltages V1 and V2 are both at high levels (indicated by the broken line V1o'of the voltage V1 and the broken line V2o'of the voltage V2 in FIG. 9), it is possible that the relays La and Lb are always in a conductive state. I understand. In this case, a current temporarily flows from the battery 12 to the motor 17, but the motor 17 is in a state where the braking force by the electromagnetic brake 18 is acting unless both the relays Lc and Ld are always in a conductive state. Rotation, that is, careless travel of the electric moving body 1 is restricted. When an abnormal signal for notification is output as a diagnosis result, it may be output to the notification unit.

If it is diagnosed in the monitoring period To that the relay La is not a failure in the continuous conduction state, the monitoring operation proceeds to the monitoring period Ta. During the monitoring period Ta, an on signal is output to the relay La and an off signal is output to the relay Lb. At this time, when the voltage V1 and the voltage V2 are at a high level (indicated by V1a of the voltage V1 in FIG. 9 and the broken line V2a'of the voltage V2), an off signal is output to the relay Ld, so that the braking force by the electromagnetic brake 18 is applied. Acts, and the rotation of the motor 17 is restricted.

Next, the monitoring operation proceeds to the monitoring period Tb, and further shifts after activation. As shown in FIG. 9, the failure monitoring operation for the relays Lc and Ld is also performed by the diagnosis execution unit 1451 and the diagnosis result processing unit 1452 in synchronization with the monitoring operation for the relays La and Lb.

After the monitoring operation for the relays La and Lb is completed, the failure monitoring operation for the relays Lc and Ld may be executed. According to this, since the relays Lc and Ld are in the off state at the time of failure diagnosis of the relays La and Lb, it is possible to prevent the motor 17 from erroneously operating such as runaway.

(Fourth Embodiment)
The fourth embodiment will be described with reference to FIGS. 10 and 11. In the fourth embodiment, the load lines of the battery 12 to the motor 17 are provided, and no protection circuit is provided. In the fourth embodiment, the monitoring start time Δts from the start of the monitoring period Ta is set shorter than the normal time Δt of the monitoring period Tb. Since the load line between the battery 12 and the motor 17 is the same as that in FIG. 4, the description thereof will be omitted.

FIG. 10 is a block diagram of the diagnostic control unit 14, and in the present embodiment, a computer is included and a part of the diagnostic processing is performed by software. The function of the diagnostic control unit 14 may be executed by the sequence circuit.

The diagnostic control unit 14 shown in FIG. 10 includes a processing unit 145 composed of, for example, a microcomputer. The processing unit 145 is connected to a storage unit 146 that stores a failure diagnosis sequence program, voltage detection circuits 141 and 142, and exciting coils (not shown) of relays La and Lb.

The processing unit 145 functions as a diagnosis execution unit 1451, a diagnosis result processing unit 1452, and a timer 1453 by executing the failure diagnosis sequence program.

The diagnosis execution unit 1451 executes a failure diagnosis sequence. For example, as shown in FIG. 11, a switching signal for turning off the load line relays La and Lb and turning them on one by one during the monitoring period To, Ta, and Tb. Is output, and the voltages V1 and V2 are measured during that time. The diagnosis execution unit 1451 sets the monitoring start time from the start time to Δt in the monitoring periods To and Tb, while setting it to Δts (<Δt) in the monitoring period Ta. Each time is timed by timer 1453.

The diagnosis result processing unit 1452 diagnoses the failure of the relays La and Lb from the voltages V1 and V2 measured during the monitoring period To, Ta and Tb.

Next, FIG. 11 is a time chart showing the failure diagnosis operation of the fourth embodiment. The failure diagnosis operation of the relays La and Lb shown in FIG. 11 is the same as that of FIG. 4 except that the time Δts from the start of the monitoring period Ta to the start of monitoring is different, so that the operation is mainly performed in the monitoring period Ta. Will be described.

If it is diagnosed in the monitoring period To that the relay La is not a failure in the continuous conduction state, the monitoring operation proceeds to the monitoring period Ta. In the monitoring period Ta, it is preferable to measure the time Δts from the start to the start of monitoring, that is, before the voltage rises completely. By doing so, even if the relay Lb is out of order and the current is short-circuited, the current flowing into the motor 17 can be reduced as much as possible. On the other hand, in the monitoring period Tb, since it is already known that there is no problem in turning off the relay La in the monitoring period Ta, there is no concern that a large current will flow into the motor 17, so that the normal measurement time Δt (voltage rises). After that), monitoring can be performed and the detection accuracy is maintained.

In the first embodiment, the number of relays connected in series is two, but three or more relays may be connected in series.

Further, in the above-described embodiment, the relays La and Lb are synchronized with the relays Lc and Ld to execute the failure diagnosis process, but after the failure diagnosis process for the relays La and Lb is completed, the relay Lc and Lb are subjected to the same procedure. The mode may be such that the failure diagnosis process of Ld is performed. According to this, since the electromagnetic brake 18 exerts a braking force on the motor 17 when the power is turned off, the electric moving body 1 does not run away even if a current flows through the motor 17 at the time of diagnosing a failure of the load line.

In the above embodiment, the electric moving body 1 is a traveling body using wheels 11, but the present invention is not limited to this, and is applied to a moving body that runs on an element other than the wheels or moves on water or in the air. It is possible. Further, another electric drive source can be adopted instead of the motor as the electric load unit.

Also, the description of the embodiments described above should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

1 Electric mobile 12 Battery (power supply)
13 Emergency stop power relay circuit unit 131 Protection circuit 14 Diagnostic control unit 17 Motor (electric load unit)
18 Electromagnetic brake (braking part)
141-144 Voltage detection circuit 1451 Diagnosis execution unit 1452 Diagnosis result processing unit 1453 Protection processing unit La to Ld relay (switch)
Lx relay

Claims (8)

Failure diagnosis processing of the first and second switches from the power supply side, which is provided between the power supply and the electric load unit driven by receiving power from the power supply and is connected in series for emergency stop, is performed. In the failure diagnosis device
A voltage detection unit that detects the voltage at each output end of the first and second switches, and
Wherein the first monitoring period first, a switching signal for turning off the second switch, the monitoring period of second changeover signal to turn on only the first switch, the output end voltage at each monitoring period Diagnostic execution unit that detects
It is provided with a diagnosis result processing unit that performs failure diagnosis of the first and second switches from each output terminal voltage in each monitoring period.
The diagnosis execution unit sets the time from the start of the second monitoring period to the detection of the output end voltage to be shorter than the time from the start of the first monitoring period to the detection of the output end voltage. ,
In the first monitoring period, the diagnosis result processing unit diagnoses whether or not the first and second switches are in a constantly conducting state from the respective output terminal voltages, and in the second monitoring period, the diagnosis result processing unit diagnoses. A failure diagnosis device characterized by diagnosing whether or not the first switch is a failure in a constantly shut-off state. The diagnosis execution unit provides a third monitoring period for outputting a switching signal that turns on only the second switch, and is the third monitoring period, from the start of the first monitoring period to the output end voltage. Each output end voltage is detected in the same time as the time until detection,
The failure diagnosis device according to claim 1, wherein the diagnosis result processing unit diagnoses the presence or absence of an abnormality on the output line of the switching signal to the first and second switches. It is interposed between said power source and said first switch, when Ru receives an abnormality signal indicating a failure from the diagnosis result processing unit, comprising a protection circuit for blocking between said power source and said first switch 請The failure diagnosis device according to claim 1 or 2. Any of claims 1 to 3, wherein the power source is provided with a braking unit that applies a braking force to the drive of the electric load unit when no power is supplied and releases the braking force when power is supplied. Failure diagnosis device described in Crab. A series-connected first and second brake switches provided between the braking unit and the power supply are provided.
The diagnosis execution unit and the diagnostic result processing unit, the first, first for the braking of the braking portion in synchronism with the execution of failure diagnosis with respect to the second switch, wherein the executing the failure diagnosis for the second switch The failure diagnosis device according to claim 4. An electric mobile body including a power source, an electric load unit driven by receiving power supplied from the power source, and a failure diagnosis device according to any one of claims 1 to 5. Failure diagnosis processing of the first and second switches from the power supply side, which is provided between the power supply and the electric load unit driven by receiving the power supply from the power supply and is connected in series for emergency stop, is performed. In the failure diagnosis method
Diagnosis executing means, said first, using a voltage detector for detecting the respective output end voltage of the second switch, respectively, wherein the first monitoring period first, a switching signal for turning off the second switch, 2 the monitoring period turn th changeover signal to turn on only said first switch, performs detection of the output end voltage in each monitoring period,
The diagnosis result processing means diagnoses the failure of the first and second switches from each output terminal voltage in each monitoring period.
The diagnosis executing means sets the time from the start of the second monitoring period to the detection of the output end voltage shorter than the time from the start of the first monitoring period to the detection of the output end voltage. ,
The diagnosis result processing means diagnoses whether or not the first and second switches are in a constantly conducting state from the respective output terminal voltages in the first monitoring period, and in the second monitoring period, the diagnosis result processing means. A failure diagnosis method characterized by diagnosing whether or not the first switch is a failure in a constantly shut-off state. Failure diagnosis processing of the first and second switches from the power supply side, which is interposed between the power supply and the electric load unit driven by receiving power from the power supply and connected in series for an emergency stop , is performed. In the failure diagnosis program to be performed by the failure diagnosis device
The first, each output end voltage of the second switch with a voltage detection unit for detecting each of said at first monitoring period first, a switching signal for turning off the second switch, second monitoring period Then, a diagnostic execution means that outputs a switching signal for turning on only the first switch and detects each output end voltage in each monitoring period.
The failure diagnosis device is made to function as a diagnosis result processing means for performing a failure diagnosis of the first and second switches from each output terminal voltage in each monitoring period.
The diagnosis executing means sets the time from the start of the second monitoring period to the detection of the output end voltage shorter than the time from the start of the first monitoring period to the detection of the output end voltage. ,
The diagnosis result processing means diagnoses whether or not the first and second switches are in a constantly conducting state from the respective output terminal voltages in the first monitoring period, and in the second monitoring period, the diagnosis result processing means. A failure diagnosis program characterized by diagnosing whether or not the first switch is a failure in a constantly shut-off state.

Images