Control system

• US 20040249478A1
• Filed: 06/02/2004
• Published: 12/09/2004
• Est. Priority Date: 06/03/2003
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Tanabe, Itaru
• Granted Patent: US 7,269,492 B2
• Time in Patent Office: Days
• US Class Current: 700/21
• CPC Class Codes: G06F 11/0736 in functional embedded systems, i.e. in a data processing system designed as a combination of hardware and software dedicated to performing a certain function testing or monitoring of automated control systems G05B23/02
• CPC Class Codes: G06F 11/0739 in a data processing system embedded in automotive or aircraft systems
• CPC Class Codes: G06F 11/0796 Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element
• CPC Class Codes: G06F 11/1441 Resetting or repowering

Abstract

To offer a control system that is not only equipped with a high fail-safe function but also capable of avoiding erroneous failure detection.

The CPU 110 outputs a drive signal DC for driving the load L according to the input signals from sensors S1 and S2 by means of the load drive element 120. The monitor IC 150 detects abnormal condition of equipment and outputs the first reset signal RES 1 for resetting the CPU 110 and also outputs the second reset signal RES2 when the first reset signal RES1 has been outputted for a specified number of times. The compulsory turn-off circuit 160 stops the output to the load L according to the second reset signal RES2 outputted from the monitor IC 150.

Claims

1. A control system equipped with a control means that outputs, according to the input signals from sensors, a drive signal for driving a load by means of a load drive element, comprising

a monitor means that detects abnormal condition of equipment and outputs the first reset signal for resetting the control means and also outputs the second reset signal when the first reset signal has been outputted for a specified number of times, and

a compulsory turn-off means that stops the output to the load according to the second reset signal outputted from the monitor means.

2. A control system according to claim 1, wherein

the compulsory turn-off means interrupts the drive signal supplied to the load drive element.

3. A control system according to claim 1, wherein

the compulsory turn-off means stops supplying power to the load.

4. A control system according to claim 1, wherein

the specified number of times which is the condition of outputting the second reset signal can be specified from the outside.

5. A control system according to claim 1, wherein

the monitor means outputs the second reset signal when the first reset signal has been outputted for a specified number of times within a specified length of time.

6. A control system according to claim 1, wherein THE MONITOR MEANS SETS A FAILURE FLAG ON WHEN THE SECOND RESET SIGNAL IS OUTPUTTED.