Sensor module and sensor system

• US 9,279,827 B2
• Filed: 11/24/2011
• Issued: 03/08/2016
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Maeda, Daisuke, Jeong, Heewon, Hayashi, Masahide
• Primary Examiner(s): Raevis, Robert R
• Application Number:
  US13/976,372
• Publication Number:
  US 20130319075A1
• Time in Patent Office: 1,566 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

Reliability and accuracy of a sensor are secured while adjustment cost of a sensor module is suppressed. A signal component analysis part 10 receives a signal output from a signal processing part 7 before passing through a low-pass filter 8, analyzes whether or not application of a fragile frequency with respect to a physical quantity is equal to or more than a threshold level, if the application of the fragile frequency is equal to or more than the threshold level, outputs output stop signals to output signal control parts 9, 16. The output signal control parts 9, 16 receive control signals output from the signal component analysis part 10, and outputs an acceleration signal and a physical quantity signal from which noise has been removed by the low-pass filters 8, 15 through the signal processing parts 7, 14.

Claims

1. A sensor module characterized by comprising:

a first detection element that detects acceleration from outside;

an acceleration signal processing unit that processes an acceleration signal detected by the first detection element;

a first filter that removes a noise from the signal processed by the acceleration signal processing unit;

a second detection element that detects another physical quantity than acceleration;

a first physical quantity signal processing unit that processes a physical quantity signal detected by the second detection element;

a second filter that removes a noise from the signal processed by the first physical quantity signal processing unit;

a signal component analysis unit that analyzes a frequency component of the signal processed by the acceleration signal processing unit, determines whether or not a physical quantity corresponding to a frequency split component representing a difference between a frequency in a drive direction of the second detection element and a frequency in a detection direction of the second detection element is applied, and, if determining that the physical quantity corresponding to the frequency split component is applied, outputs an output stop signal;

a first output control unit that stops output of the signal output from the first filter when the output stop signal is output from the signal component analysis unit; and

a second output control unit that stops output of the signal output from the second filter when the output stop signal is output from the signal component analysis unit.

2. The sensor module according to claim 1, wherein the first and the second output control units output flags representing that the signal output is stopped when the output stop signal is output from the signal component analysis unit.

3. The sensor module according to claim 1, wherein the physical quantity detected by the second detection element is an angular velocity.

4. The sensor module according to claim 1, wherein the acceleration signal processing unit, the first and the second filters, the signal component analysis unit, the first and the second output control units, and the first physical quantity signal processing unit are formed on one semiconductor chip.

5. The sensor module according to claim 1, further comprising:

a third detection element that detects another physical quantity than acceleration;

a second physical quantity signal processing unit that processes a physical quantity signal detected by the third detection element;

a third filter that removes a noise from the signal processed by the second physical quantity signal processing unit; and

a third output control unit that stops output of the signal output from the third filter when the output stop signal is output from the signal component analysis unit.

6. The sensor module according to claim 5, wherein the physical quantity detected by the second detection element is an angular velocity.

7. The sensor module according to claim 1, further comprising:

a first semiconductor chip on which the acceleration signal processing unit, the first filter, the first output control unit, and the signal component analysis unit are formed; and

a second semiconductor chip on which the first physical quantity signal processing unit, the second filter, and the second output control unit are formed,

wherein the first semiconductor chip is connected to the second semiconductor chip by a bonding wire, and transmits the output stop signal output from the signal component analysis unit to the second output control unit via the bonding wire.

8. The sensor module according to claim 1, further comprising:

a first semiconductor chip on which the acceleration signal processing unit, the first filter, and the first output control unit are formed; and

a second semiconductor chip on which the first physical quantity signal processing unit, the second filter, the second output control unit, and the signal component analysis unit are formed,

wherein the second semiconductor chip is connected to the first semiconductor chip by a bonding wire, and transmits the output stop signal output from the signal component analysis unit to the first output control unit via the bonding wire.

9. A sensor system characterized by comprising:

a sensor module having a first detection element that detects acceleration from outside, an acceleration signal processing unit that processes an acceleration signal detected by the first detection element, a first filter that removes a noise from the signal processed by the acceleration signal processing unit, a second detection element that detects another physical quantity than acceleration, a first physical quantity signal processing unit that processes a physical quantity signal detected by the second detection element, and a second filter that removes a noise from the signal processed by the first physical quantity signal processing unit; and

a processor that controls an actuator according to the signals output via the first and the second filters,

wherein the processor has

a signal component analysis unit that analyzes a frequency component of the signal processed by the acceleration signal processing unit, determines whether or not a physical quantity corresponding to a frequency split component representing a difference between a frequency in a drive direction of the second detection element and a frequency in a detection direction of the second detection element is applied, and, if determining that the physical quantity corresponding to the frequency split component is applied, outputs an output stop signal, and

an internal state determination unit that makes a transition to a state in which the processor does not perform the control of the actuator when the stop signal is output from the signal component analysis unit.

10. The sensor system according to claim 9, wherein the physical quantity detected by the second detection element is an angular velocity.

11. The sensor system according to claim 9, wherein the sensor module further comprising:

a third detection element that detects another physical quantity than acceleration;

a second physical quantity signal processing unit that processes a physical quantity signal detected by the third detection element;

a third filter that removes a noise from the signal processed by the second physical quantity signal processing unit; and

a third output control unit that stops output of the signal output from the third filter when the output stop signal is output from the signal component analysis unit.

12. The sensor system according to claim 11, wherein the physical quantity detected by the second detection element is an angular velocity.

13. A sensor system characterized by comprising:

a sensor module having a first detection element that detects acceleration from outside, an acceleration signal processing unit that processes an acceleration signal detected by the first detection element, a first filter that removes a noise from the signal processed by the acceleration signal processing unit, a second detection element that detects another physical quantity than acceleration, a first physical quantity signal processing unit that processes a physical quantity signal detected by the second detection element, and a second filter that removes a noise from the signal processed by the first physical quantity signal processing unit; and

a processor that controls an actuator according to the signals output via the first and the second filters,

wherein the processor has

a signal component analysis unit that analyzes a frequency component of the signal output from the first filter, determines whether or not a physical quantity corresponding to a frequency split component representing a difference between a frequency in a drive direction of the second detection element and a frequency in a detection direction of the second detection element is applied, and, if determining that the physical quantity corresponding to the frequency split component is applied, outputs an output stop signal, and

an internal state determination unit that makes a transition to a state in which the processor does not perform the control of the actuator when the stop signal is output from the signal component analysis unit.

14. The sensor system according to claim 13, wherein the physical quantity detected by the second detection element is an angular velocity.

15. The sensor system according to claim 13, wherein the sensor module further comprising:

a third detection element that detects another physical quantity than acceleration;

a second physical quantity signal processing unit that processes a physical quantity signal detected by the third detection element;

a third filter that removes a noise from the signal processed by the second physical quantity signal processing unit; and

a third output control unit that stops output of the signal output from the third filter when the output stop signal is output from the signal component analysis unit.

16. The sensor system according to claim 15, wherein the physical quantity detected by the second detection element is an angular velocity.