Joint bending state determining device and method

Patent metadata

Field	Value
Publication number	US-11672443-B2
Application number	US-202016815360-A
Country	US
Kind code	B2
Filing date	Mar 11, 2020
Priority date	Nov 20, 2019
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A joint bending state determining device comprises a sensor group and a processor. The sensor group comprises first and second gravity sensors. The first/second gravity sensor generates a first/second polar angle and a first/second azimuth angle. The processor obtains a first length corresponding to the first gravity sensor and a second length corresponding to the second gravity sensor, obtains a set of coordinates of a joint in a coordinate system according to the first polar angle, the first azimuth angle and the first length, obtains a set of coordinates of the second gravity sensor in the coordinate system according to the set of coordinates of the joint, the second polar angle, the second azimuth angle and the second length, and obtains a joint angle according to the set of coordinates of the second gravity sensor in the coordinate system, the first length and the second length.

First claim

What is claimed is:

1. A joint bending state determining device, comprising:
a sensor group comprising:
a first gravity sensor configured to generate a first polar angle and a first azimuth angle; and
a second gravity sensor configured to generate a second polar angle and a second azimuth angle; and

a processor connected with the sensor group, and configured to obtain a first length corresponding to the first gravity sensor and a second length corresponding to the second gravity sensor, to obtain a set of coordinates of a joint in a coordinate system according to the first polar angle, the first azimuth angle and the first length, to obtain a set of coordinates of the second gravity sensor in the coordinate system according to the set of coordinates of the joint, the second polar angle, the second azimuth angle and the second length, and to obtain a joint angle according to the set of coordinates of the second gravity sensor in the coordinate system, the first length and the second length;
wherein the first length is associated with a distance between the first gravity sensor and the set of coordinates of the joint, and the second length is associated with a distance between the second gravity sensor and the set of coordinates of the joint; and
wherein the processor is further configured to obtain a first charge level of the first gravity sensor and a second charge level of the second gravity sensor, to control the first gravity sensor to capture the second polar angle and the second azimuth angle from the second gravity sensor and return the second polar angle and the second azimuth angle to the processor in response to determining that the first charge level is higher than the second charge level, and to control the second gravity sensor to capture the first polar angle and the first azimuth angle from the first gravity sensor and return the first polar angle and the first azimuth angle to the processor in response to determining that the first charge level is lower than the second charge level; or
wherein the first gravity sensor has the first charge level and is further configured to obtain the second charge level of the second gravity sensor, to capture the second polar angle and the second azimuth angle from the second gravity sensor and transmit the second polar angle and the second azimuth angle to the processor in response to determining that the first charge level is higher than the second charge level, and to transmit the first polar angle and the first azimuth angle to the second gravity sensor in response to determining that the first charge level is lower than the second charge level.

2. The joint bending state determining device according to claim 1 , wherein the processor obtains the set of coordinates of the joint by obtaining a first x coordinate according to the first length, a sine value of the first polar angle and a cosine value of the first azimuth angle, obtaining a first y coordinate according to the first length, the sine value of the first polar angle and a sine value of the first azimuth angle, obtaining a first z coordinate according to the first length and a cosine value of the first polar angle, and grouping the first x coordinate, the first y coordinate and the first z coordinate to form the set of coordinates of the joint.

3. The joint bending state determining device according to claim 2 , wherein the processor obtains the set of coordinates of the second gravity sensor in the coordinate system by obtaining a second x coordinate according to the first x coordinate, the second length, a sine value of the second polar angle and a cosine value of the second azimuth angle, obtaining a second y coordinate according to the first y coordinate, the first x coordinate, the second x coordinate and a tangent value of the second azimuth angle, obtaining a second z coordinate according to the first z coordinate, the second length and a cosine value of the second polar angle, and grouping the second x coordinate, the second y coordinate and the second z coordinate to form the set of coordinates of the second gravity sensor in the coordinate system.

4. The joint bending state determining device according to claim 1 , wherein the processor obtains the joint angle by obtaining a distance between an origin and the set of coordinates of the second gravity sensor in the coordinate system, and obtaining the joint angle according to the distance between the origin and the set of coordinates of the second gravity sensor in the coordinate system, the first length, the second length and a cosine rule.

5. The joint bending state determining device according to claim 1 , wherein before obtaining the set of coordinates of the joint, the processor is further configured to determine that a predetermined axis of the first gravity sensor matches a gravity axis to ground and accordingly determine that the first gravity sensor corresponds to the first length.

6. The joint bending state determining device according to claim 1 , wherein before the processor obtains the set of coordinates of the joint, the first gravity sensor is further configured to determine that a predetermined axis of the first gravity sensor matches a gravity axis to ground and notify the processor to allow the processor to determine that first gravity sensor corresponds to the first length.

7. The joint bending state determining device according to claim 1 , wherein the processor is disposed on a same circuit board as the first gravity sensor or the second gravity sensor.

8. The joint bending state determining device according to claim 1 , further comprising an input interface that is connected with the processor and configured to receive the first length and the second length.

9. A joint bending state determining method, comprising:
obtaining a first length corresponding to a first gravity sensor and a second length corresponding to a second gravity sensor;
using one of the first gravity sensor and the second gravity sensor which has a higher charge level to collect information of a first polar angle and a first azimuth angle generated by the first gravity sensor and a second polar angle and a second azimuth angle generated by the second gravity sensor and to transmit the information to a processor;
obtaining a set of coordinates of a joint in a coordinate system according to the first polar angle, the first azimuth angle and the first length;
obtaining a set of coordinates of the second gravity sensor in the coordinate system according to the set of coordinates of the joint, the second polar angle, the second azimuth angle and the second length; and
obtaining a joint angle according to the set of coordinates of the second gravity sensor in the coordinate system, the first length and the second length;
wherein the first length is associated with a distance between the first gravity sensor and the set of coordinates of the joint, and the second length is associated with a distance between the second gravity sensor and the set of coordinates of the joint; and
wherein using the one of the first gravity sensor and the second gravity sensor which has the higher charge level to collect the information of the first polar angle and the first azimuth angle generated by the first gravity sensor and the second polar angle and the second azimuth angle generated by the second gravity sensor and to transmit the information to the processor comprises:
obtaining a first charge level of the first gravity sensor and a second charge level of the second gravity sensor;
controlling the first gravity sensor to capture the second polar angle and the second azimuth angle from the second gravity sensor and return the second polar angle and the second azimuth angle in response to the first cha

Assignees

• Wistron Corp

Inventors

• Hsu Chunpeng
• Liao Hsin-Hui
• Kao Yi-Sheng
• Tsai Tsung-Yu
• Chen tai-yun

Classifications

• G01B21/22 Primary

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• A61B5/0024

  for multiple sensor units attached to the patient, e.g. using a body or personal area network · CPC title

• A61B5/1121 Primary

  Determining geometric values, e.g. centre of rotation or angular range of movement · CPC title

• A61B5/1126

  using a particular sensing technique · CPC title

• A61B5/4528

  Joints (A61B5/4533, A61B5/4538 take precedence) · CPC title