Control system

• US 8,860,258 B2
• Filed: 01/13/2011
• Issued: 10/14/2014
• Est. Priority Date: 01/14/2010
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Matsumoto, Tsuyoshi, Iida, Tatsuya
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US13/006,395
• Publication Number:
  US 20110169345A1
• Time in Patent Office: 1,370 Days
• Field of Search: 307/140
• US Class Current: 307/140
• CPC Class Codes: G05B 9/02 electric

Abstract

A control system has an input instrument that generates a signal indicating permission and prohibition of running of a load, a power-supply unit that is configured to supply driving power to the load when the load is permitted to run by an input signal from the input instrument, and to cut off the supply of the driving power to the load when the load is prohibited from running by the input signal, and a monitoring device that is configured to monitor the input instrument and the power-supply unit. The power-supply unit is configured to cut off the supply of the driving power to the load when monitoring result of the monitoring device indicates an abnormality of one of the input instrument and the power-supply unit. The control system is compatible with category 2 of ISO 13849-1.

Claims

1. A control system comprising:

an input instrument configured to generate a signal indicating permission and prohibition of running of a load;

a power-supply unit configured to receive an input signal output from the input instrument, supply a three-phase driving power to the load when the load is permitted to run by the input signal from the input instrument, and cut off the supply of the three-phase driving power to the load when the load is prohibited from running by the input signal; and

a monitoring device configured to monitor the input instrument and the power-supply unit,

wherein the power-supply unit includes a first output unit and a second output unit, the first output unit is configured to cut off the supply of the three-phase driving power to the load when the load is prohibited from running by the input signal, the second output unit is configured to cut off the supply of the three-phase driving power to the load when a monitoring result of the monitoring device indicates an abnormal state in at least one of the input instrument and the first output unit, and

wherein the control system is compatible with category 2 of ISO 13849-1.

2. The control system according to claim 1, wherein the monitoring device is not compatible with the category 2 of ISO 13849-1.

3. The control system according to claim 2, wherein the input instrument includes:

a first signal generating unit configured to generate a first signal as the input signal input to the power-supply unit; and

a second signal generating unit configured to generate a second signal indicating the permission and prohibition of the running of the load, wherein

the power-supply unit outputs by the first output unit a third signal indicating the supply of the three-phase driving power to the load and the cutoff of the supply of the three-phase driving power, the supply of the three-phase driving power and the cutoff of the supply of the three-phase driving power being performed by the power-supply unit, and

the monitoring device monitors the input instrument and the first output unit based on the second signal and the third signal.

4. The control system according to claim 3, wherein the monitoring device monitors a time difference between timing of a change of the second signal and timing of a change of the third signal, when the load is permitted to run, and when the load is prohibited from running.

5. The control system according to claim 4, wherein the monitoring device detects that the input instrument and the first output unit are normal by detecting that the time difference falls within a predetermined time.

6. The control system according to claim 4, wherein the monitoring device detects that the input instrument is abnormal, when a state of the second signal is not changed so as to indicate that the load is prohibited from running within a reference time since a state of the third signal is changed so as to indicate that the supply of the three-phase driving power to the load is cut off.

7. The control system according to claim 4, wherein the monitoring device detects that the first output unit is abnormal, when a state of the third signal is not changed so as to indicate that the three-phase driving power is supplied to the load within a reference time since a state of the second signal is changed so as to indicate that the load is permitted to run.

8. The control system as in claim 1,

wherein the power-supply unit includes a first contactor as the first output unit and a second contactor as the second output unit that are inserted in and connected to a feeding pathway between the load and the three-phase driving power unit, and

wherein the first contactor includes:

a first relay that is provided in the feeding pathway to become an opened state and a closed state according to the first signal; and

a second relay that is opened and closed independently of the first relay to generate the third signal.

9. The control system according to claim 8, further comprising a control device that is configured to control to put the first relay in the opened state and the closed state according to the input signal from the input instrument.

10. The control system as in claim 1, wherein the load is a motor, and the power-supply unit is a servo driver that drives the motor.