METHOD FOR ESTIMATING POSTURE OF ROBOTIC WALKING AID

• US 20170151070A1
• Filed: 12/29/2015
• Published: 06/01/2017
• Est. Priority Date: 11/27/2015
• Status: Active Application

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Sun, Kuan-Chun, Tsai, Yi-Jeng, Hu, Jwu-Sheng, Wu, Cheng-Hua
• Application Number:
  US14/982,881
• Publication Number:
  US 20170151070A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/112 Gait analysis
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/689 Alarm means, e.g. acoustic
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61H 1/0255 Both knee and hip of a patient, e.g. in supine or sitting position, the feet being moved in a plane substantially parallel to the body-symmetrical-plane A61H1/0214 takes precedence
• CPC Class Codes: A61H 1/0266 Foot
• CPC Class Codes: A61H 2201/0192 Specific means for adjusting dimensions
• CPC Class Codes: A61H 2201/1207 with electric or magnetic drive
• CPC Class Codes: A61H 2201/1628 Pelvis
• CPC Class Codes: A61H 2201/164 Feet or leg, e.g. pedal
• CPC Class Codes: A61H 2201/165 Wearable interfaces
• CPC Class Codes: A61H 2201/50 Control means thereof
• CPC Class Codes: A61H 2201/5061 Force sensors
• CPC Class Codes: A61H 2201/5064 Position sensors
• CPC Class Codes: A61H 2201/5069 Angle sensors
• CPC Class Codes: A61H 2201/5084 Acceleration sensors
• CPC Class Codes: A61H 2201/5097 wireless
• CPC Class Codes: A61H 2205/108 for the upper legs
• CPC Class Codes: A61H 3/00 Appliances for aiding patients or disabled persons to walk about apparatus for helping babies to walk A47D13/04; orthopaedic devices for correcting deformities of, or supporting, limbs A61F5/0102; exercising apparatus for the feet or toes A63B23/10; stairways or ramps E04F11/00
• CPC Class Codes: B25J 9/0006 : Exoskeletons, i.e. resembling a human figure
• CPC Class Codes: G05B 2219/37134 : Gyroscope
• CPC Class Codes: G05B 2219/37388 : Acceleration or deceleration, inertial measurement
• CPC Class Codes: G05B 2219/40305 : Exoskeleton, human robot interaction, extenders
• CPC Class Codes: H04W 4/02 : Services making use of location information
• CPC Class Codes: H04W 4/029 : Location-based management or tracking services

Abstract

A method for estimating posture of robotic walking aid comprises: providing a motor controller, a motor encoder and a motor on right and left hip joints, and right and left knee joints of a robotic walking aid, providing an inertial sensor on upper body of the robotic walking aid, wherein the motor controller, the motor encoder, the motor and the inertial sensor are coupled to a control unit; installing the robotic walking aid on a user; inputting the lengths of the upper body, two thighs, two shanks, two feet of the robotic walking aid to the control unit, wherein the upper body, two thighs, two shanks, two feet form a plurality of points; obtaining an angle of the upper body corresponding to a reference frame with the inertial sensor; obtaining angles of those joints with those motor encoders; and calculating 3 dimensional coordinates of each point with a motion model.

Claims

1. A method for estimating posture of a robotic walking aid, comprising the steps of:

providing a motor controller, a motor encoder and a motor on each of right and left hip joints, and right and left knee joints of a robotic walking aid, and providing an inertial sensor on upper body of the robotic walking aid, while coupling the motor controllers, the motor encoders, the motors and the inertial sensor to a control unit;

installing the robotic walking aid on a user;

with the robotic walking aid installed on the user, an angle of the upper body of the robotic walking aid being formed corresponding to a reference frame, and each of the aforesaid joints having an individual angle;

inputting the lengths of the upper body, two thighs, two shanks, two feet of the robotic walking aid to the control unit, while the upper body, two thighs, two shanks, two feet forming a plurality of end points;

using the inertial sensor to obtain the angle of the upper body corresponding to the reference frame;

using the motor encoders to obtain the individual angle of each of the aforesaid joints; and

using a motion model to calculate three dimensional ( 3D ) coordinates for each of the plurality of end points.

2. The method of claim 1, wherein after the step of using of the motion model to calculate 3D coordinates for each of the plurality of end points is performed, a process for calculating 3D coordinates of the center of gravity of the user is performed, and the process comprises the steps of:

calculating mass of the upper body, the two thighs, the two shanks and the two feet; and

using the 3D coordinates of each of the plurality of end points and the mass of the upper body, the two thighs, the two shanks and the two feet to calculate 3D coordinates of the center of gravity of the robotic walking aid.

3. The method of claim 2, wherein after the center of gravity of the robotic walking aid is obtained, a process for determining whether the 3D coordinates of the center of gravity of the user is abnormal is performed, and the process comprises the steps of:

using the two end points corresponding to the two feet to construct a base of support;

projecting the 3D coordinates of the center of gravity to the base of the support; and

determining whether the 3D coordinates of the center of gravity is projected and located outside the base of support; and

if so, issuing an alarm or enabling the robotic walking aid to rest;

otherwise, returning to the step of using the inertial sensor to obtain the angle of the upper body corresponding to the reference frame.

4. The method of claim 1, wherein the robotic walking aid is defined by a plurality of links, and the plurality of links include:

a first link and a second link, serially connected to each other to compose a pelvis;

a third link, a fourth link, and a fifth link, serially connected to one another to compose a right leg while allowing the right leg to couple to one end of the pelvis in a form that a node between the right leg and the pelvis is defined to be the right hip joint, a node between the third link and the fourth link is defined to be the right knee joint, and the fifth link is defined to be the right foot;

a sixth link, a seventh link, and an eighth link, serially connected to one another to compose a left leg while allowing the left leg to couple to one end of the pelvis that is not connected to the right leg in a form that a node between the left leg and the pelvis is defined to be the left hip joint, a node between the sixth link and the seventh link is defined to be the left knee joint, and the eighth link is defined to be the left foot; and

a ninth link, used as the upper body and one end thereof being connected to a node between the first link and the second link

5. The method of claim 4, wherein the plurality of end points include:

a first end point, disposed at an end of the ninth link that is connected to the first and the second links;

an upper body end point, disposed at an end of the ninth link that is opposite to the first end point;

a second end point, disposed at an end of the third link that is connected to the first link;

a third end point, disposed at an end of the third link that is connected to the fourth link;

a fourth end point, disposed at an end of the fourth link that is connected to the fifth link;

a fifth end point, disposed at an end of the fifth link that is opposite to the fourth end point;

a sixth end point, disposed at an end of the sixth link that is connected to the second link;

a seventh end point, disposed at an end of the sixth link that is connected to the seventh link;

an eighth end point, disposed at an end of the seventh link that is connected to the eighth link; and

a ninth end point, disposed at an end of the eighth link that is opposite to the eighth end point.

6. The method of claim 5, wherein in the step of using the motion model to calculate 3D coordinates for each of the plurality of end points, a direction that the user is walking toward is defined to be the positive direction of an x-axis in the reference frame;

the node between the upper body and the pelvis of the robotic walking aid is defined to be the origin of the reference frame while respectively defining the first end point to the ninth end point to be the origins of a sub-coordinate frame 1 to a sub-coordinate frame 9 and the upper body end point to be the origin of a sub-coordinate frame 0; and

consequently the 3D coordinates of each of the first end point to the ninth end point and the upper body end point corresponding to the reference frame can be obtained by a homogeneous transformation matrixes defined by the plurality of the aforesaid end points.

7. The method of claim 1, wherein the control unit is connected to a mobile communication device with GPS function and a database, wherein the mobile communication device with GPS function provides the GPS coordinates of the user with the robotic walking aid installed on, and the GPS coordinates of the user and the angles relating to the upper body and the aforesaid joints of the robotic walking aid are stored in the database for further use in remote service.

8. The method of claim 7, wherein the remote service includes a topography feedback process, a danger prompting process, a falling alert and distress call process, an exercise amount estimation process, a walking distance estimation process, a behavior monitoring process, an activity record process, and a rehabilitation feedback process.

9. The method of claim 8, wherein in the topography feedback process, the GPS coordinates of the user is matched to a map for identifying terrains of specific topographic marks, and when a user approaches any of those specific topographic marks, a remote prompting is issued for suggesting the user to alter his/her walking mode for adapting to the terrain of the approached topographic mark.

10. The method of claim 8, wherein in the danger prompting process, the GPS coordinates of the user is matched to a map for identifying dangerous locations, and when a user approaches any of those dangerous locations, a remote prompting is issued for alerting the user to cope with the coming danger.

11. The method of claim 8, wherein in the falling alert and distress call process, the posture of the user is obtained using the angles relating to the upper body and the aforesaid joints of the robotic walking aid, and when the posture is determined to be abnormal, a call is made to find out the condition of the user, and if there is no response from the user, an active distress call is issued to an emergency medical unit that is located nearest to the user according to the GPS coordinates of the user.

12. The method of claim 8, wherein in the exercise amount estimation process, an exercise amount is calculated and obtained using the following formula:

(m_r+m_h)×

g×

d=W_r+W_h;

and m_r is the mass of the robotic walking aid;

g is the gravitational acceleration;

m_h is the mass of the user;

d is the walking distance;

W_r is the mechanic energy generated by the robotic walking aid; and

W_h is the exercise amount of the user.

13. The method of claim 12, wherein W_r=W_mechanical=η

W_electrical; and

W_mechanical is the mechanical energy generated by the robotic walking aid;

W_electrical is the electrical energy consumed by the robotic walking aid; and

is the conversion efficiency.

14. The method of claim 8, wherein in the walking distance estimation process, a posture of the user is obtained remotely using the angles relating to the upper body and the aforesaid joints of the robotic walking aid and a step length of the user is estimated so as to be used for estimating and recording the walking distance.

15. The method of claim 8, wherein in the behavior monitoring process, postures of the user are obtained remotely using the angles relating to the upper body and the aforesaid joints of the robotic walking aid, and the postures of the user are classified into different behaviors according to a classification rule to be recorded.

16. The method of claim 8, wherein in the activity record process, the GPS coordinates of the user are matched to a map for identifying and recording places where the user perform his/her daily activities.

17. The method of claim 8, wherein in the rehabilitation feedback process, the posture, step length, step frequency, and exercise amount are recorded and provided remotely to a rehabilitation therapist for constructing a rehabilitation treatment accordingly.