Method for evaluating output signals of a rotational rate sensor unit and rotational rate sensor unit

• US 9,671,227 B2
• Filed: 06/19/2012
• Issued: 06/06/2017
• Est. Priority Date: 08/16/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Claus, Thomas, Bartholomeyczik, Julian
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US14/238,916
• Publication Number:
  US 20140298907A1
• Time in Patent Office: 1,813 Days
• Field of Search: 7350412, 73510, 73511
• 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 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems

Abstract

A method for evaluating output signals of a rotational rate sensor unit, including providing an n-tuple of angular speed values measured by at least one rotational rate sensor of the rotational rate sensor unit, in a first step; determining an intermediate value as a function of the n-tuple of angular speed values, in a second step; calculating a new change of orientation value as a function of the intermediate value and an earlier change of orientation value stored in a register of the rotational rate sensor unit, in a third step; and storing the new change of orientation value in the register, in a fourth step, repeating the first, second, third, and fourth step until, the new change of orientation value is read out by an external data processing unit connected to the rotational rate sensor unit, and/or, an exceeding of a threshold value is detected.

Claims

1. A method for evaluating output signals of a rotational rate sensor unit, comprising:

providing an n-tuple-of angular speed values measured by at least one rotational rate sensor of the rotational rate sensor unit, in a first method step;

determining an intermediate value as a function of the n-tuple of angular speed values, in a second method step;

calculating a new change of orientation value as a function of the intermediate value and as a function of an earlier change of orientation value stored in a register of the rotational rate sensor unit, in a third method step; and

storing the new change of orientation value in the register, in a fourth method step;

wherein the first, second, third, and fourth method steps are repeated until, at least one of;

i) in a fifth method step, the new change of orientation value is read out by an external data processing unit connected to the rotational rate sensor unit, and ii) in a sixth method step, an exceeding of a threshold value is detected, and

wherein a current change of orientation value is successively summed by multiple repetition of a loop including the first, second, third, and fourth method steps, so that all of the items of change of position information are represented in the new change of orientation value.

2. The method as recited in claim 1, wherein the earlier change of orientation value stored in the register is set, in a seventh method step, to an original value, in which no change of the orientation has taken place, after execution of the fifth or sixth method step, and the method being restarted with the first method step.

3. The method as recited in claim 1, wherein the new change of orientation value includes a change of a quaternion.

4. The method as recited in claim 1, wherein the sixth method step includes detecting whether a length of the new change of orientation value calculated in the third method step exceeds at least one of a configurable threshold value and a prespecified threshold value.

5. The method as recited in claim 1, wherein the sixth method step includes counting by a counter the number of third method steps carried out since the earlier change of orientation value stored in the register was last set to an original value, in which no change of the orientation has taken place, and detecting whether the counter exceeds at least one of a configurable further threshold value and a prespecified further threshold value.

6. The method as recited in claim 1, further comprising:

storing at least one of the new and the earlier orientation value in an output register that can be read out by the external data processing unit, the storage taking place if, in the sixth method step, an exceeding of a threshold is detected.

7. The method as recited in claim 1, wherein at least one of:

i) in the second method step, the intermediate value is calculated as a linear function of the n-tuple of angular speed values, and ii) in the third method step, the new change of orientation value is calculated by a quaternion multiplication of the intermediate value by the earlier change of orientation value stored in the register.

8. The method as recited in claim 2, wherein a plurality of change of orientation values read out from the rotational rate sensor unit in fifth method steps is summed, in an eighth method step, by the external data processing unit to form an effective change of orientation value.

17. The method as recited in claim 1, wherein in the second method step the intermediate value is calculated as a linear function of the n-tuple of angular speed values.

18. The method as recited in claim 1, wherein in the second method step the intermediate value is calculated as a linear function of the n-tuple of angular speed values, and wherein the approximation through a linear function is performed as follows:

19. The method as recited in claim 1, wherein the sampling rate is less than about 100 Hz.

9. A rotational rate sensor unit, comprising:

at least one rotational rate sensor to determine an n-tuple of angular speeds;

an evaluation circuit to determine an intermediate value as a function of the n-tuple of angular speeds; and

a register to store a change of orientation value;

wherein the evaluation circuit further being configured to calculate a new change of orientation value as a function of the intermediate value and as a function of an earlier change of orientation value stored in the register, and the rotational rate sensor unit is fashioned in such a way that the new change of orientation value is capable of being read out by an external data processing unit connected to the rotational rate sensor unit, and

wherein a current change of orientation value is successively summed by multiple repetition of a loop including the first, second, third, and fourth method steps, so that all of the items of change of position information are represented in the new change of orientation value.

10. The rotational rate sensor unit as recited in claim 9, wherein the evaluation circuit is configured to reset the earlier change of orientation value stored in the register when the new change of orientation value is read out.

11. The rotational rate sensor as recited in claim 9, further comprising:

a monitoring unit to monitor a length of the new change of orientation value realized as a change of orientation vector as indicating an exceeding of a threshold value.

12. The rotational rate sensor unit as recited in claim 9, further comprising:

a counter to count the calculations of the new change of orientation value carried out by the evaluation circuit to indicate an exceeding of a threshold value.

13. The rotational rate sensor unit as recited in claim 9, wherein the rotational rate sensor includes a three-channel rotational sensor.

14. The rotational rate sensor unit as recited in claim 9, wherein the evaluation circuit is an ASIC.

15. The rotational rate sensor unit as recited in claim 9, wherein the intermediate value is calculated as a linear function of the n-tuple of angular speed values.

16. The rotational rate sensor unit as recited in claim 9, wherein the intermediate value is calculated as a linear function of the n-tuple of angular speed values, and wherein the approximation through a linear function is performed as follows:

20. The rotational rate sensor unit as recited in claim 9, wherein the sampling rate is less than about 100 Hz.