Control device of an electromagnetic actuator for a restraint means

• US 9,975,511 B2
• Filed: 06/01/2015
• Issued: 05/22/2018
• Est. Priority Date: 06/05/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Karner, Ruediger, Schumacher, Hartmut
• Primary Examiner(s): Lee, Tyler J
• Application Number:
  US15/310,410
• Publication Number:
  US 20170158152A1
• Time in Patent Office: 1,086 Days
• Field of Search: 701 36- 45
• CPC Class Codes: B60R 2021/01184 Fault detection or diagnostic circuits in power circuits B60R2021/01129
• CPC Class Codes: B60R 2021/01231 control of expansion timing or sequence
• CPC Class Codes: B60R 2021/26094 characterised by fluid flow controlling valves
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• CPC Class Codes: B60R 21/268 using instantaneous release of stored pressurised gas B60R21/26005 takes precedence
• CPC Class Codes: H01F 7/1805 Circuit arrangements for holding the operation of electromagnets or for holding the armature in attracted position with reduced energising current for holding relay armature in attracted position with reduced energising current H01H47/04; quick energising of electro-dynamic machines H02P9/08; for quickly de-energising of dynamo-electric generators H02P9/123
• CPC Class Codes: H01H 47/325 by switching regulator

Abstract

A control device of an electromagnetic actuator for a restraint device, including an evaluation and control unit which generates a control signal which predefines a control sequence having control time periods, in which the actuator is activated, and pause time periods, in which the actuator is deactivated. A protective circuit including a counter is provided, the counter monitoring the control sequence and increments its counter content during the at least one control time period and decrements its counter content during the at least one pause time period, the protective circuit effectuating a deactivation of the actuator when the counter content reaches or exceeds a predefined first threshold value, and allows a reactivation of the actuator when the counter content reaches or falls below a predefined second threshold value after reaching or exceeding the first threshold value, the first counter content being greater than the second counter content.

Claims

1. A control device of an electromagnetic actuator for a restraint device, the control device comprising:

an evaluation and control unit which is designed to generate at least one control signal as a function of a triggering decision which was reached, the control signal determining a chronological sequence of the control of the actuator and predefines a control sequence having at least one control time period in which the actuator is activated, and at least one pause time period in which the actuator is deactivated; and

a protective circuit including a counter, the counter configured to monitor the control sequence, to increment its counter content by a first count value during the at least one control time period, and to decrement its counter content by a second count value during the at least one pause time period, the protective circuit designed to effectuate a deactivation of the actuator when the counter content reaches or exceeds a predefined first threshold value, and allow a reactivation of the actuator when the counter content reaches or falls below a predefined second threshold value after reaching or exceeding the first threshold value, the first threshold value being greater than the second threshold value.

2. The control device as recited in claim 1, wherein the at least one control time period corresponds to a pulse duration or a dwell time duration.

3. The control device as recited in claim 2, wherein the evaluation and control unit is designed to generate, with the aid of a first control signal, a pulse-shaped actuator current, which activates the actuator.

4. The control device as recited in claim 3, wherein the evaluation and control unit is designed to generates, with the aid of a second control signal, a constant actuator current having a predefined value when the pulse-shaped actuator current reaches a predefined first threshold value, the constant actuator current holding the actuator in the activated state.

5. The control device as recited in claim 4, wherein the evaluation and control unit is designed to deactivate the actuator with the aid of a third control signal.

6. The control device as recited in claim 1, wherein the electro-magnetic actuator is a solenoid valve, via which a restraint device, which is an airbag, is fillable with a cold gas, a number of the control time periods and the pause time periods within a predefined time period being predefinable as a function of the desirable filling capacity of the airbag per unit of time.

7. A control device of an electromagnetic actuator for a restraint device, the control device comprising:

an evaluation and control unit which is designed to generate at least one control signal as a function of a triggering decision which was reached, the control signal determining a chronological sequence of the control of the actuator and predefines a control sequence having at least one control time period in which the actuator is activated, and at least one pause time period in which the actuator is deactivated; and

a protective circuit including a counter which monitors the control sequence and increments its counter content during the at least one control time period and decrements its counter content during the at least one pause time period, the protective circuit designed to effectuate a deactivation of the actuator when the counter content reaches or exceeds a predefined first threshold value, and allow a reactivation of the actuator when the counter content reaches or falls below a predefined second threshold value after reaching or exceeding the first threshold value, the first threshold value being greater than the second threshold value;

wherein the at least one control time period corresponds to a pulse duration or a dwell time duration, and

wherein the counter increments the counter content during the pulse duration by a predefined first counting stage and, during the dwell time duration, by a predefined second counting stage which is smaller than the first counting stage.

8. The control device as recited in claim 7, wherein the first counting stage is dependent on the predefined first threshold value of the pulse-shaped actuator current, and the second counting stage is dependent on the predefined value of the constant actuator current.

9. The control device as recited in claim 8, wherein the counter decrements the counter content during the pause duration by a third counting stage.

10. The control device as recited in claim 9, wherein the third counting stage is dependent on at least one of:

i) a thermal resistance of the control device, and ii) an instantaneous temperature of the control device.