Metrics for Description of Human Capability in Execution of Operational Tasks

• US 20140100828A1
• Filed: 10/01/2013
• Published: 04/10/2014
• Est. Priority Date: 10/08/2012
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Dariush, Behzad
• Granted Patent: US 9,875,335 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: B60N 2/00 Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles railway seats B61D33/00; cycle seats B62J1/00; aircraft seats B64D11/06, B64D25/04, B64D25/10
• CPC Class Codes: G06F 30/15 Vehicle, aircraft or watercraft design
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics

Abstract

Manipulability metrics are used to evaluate the feasibility of a vehicle occupant package design. A manipulability metric quantifies the ability of a virtual human subject to carry out an operational task in the design. Examples of specific manipulability metrics include a force metric quantifying the subject'"'"'s ability apply a joint torque as a force to a component of the design, a velocity metric quantifying the subject'"'"'s ability to cause the component to achieve velocity, and a dynamic metric quantifying the subject'"'"'s ability to cause the component to achieve acceleration. Manipulability metrics are determined using a Jacobian determined as part of a determination of a posture of the subject carrying out the task. The manipulability metric is further determined using an endpoint direction of motion and a combination differential kinematics and static equilibrium considerations.

Claims

1. A computer-implemented method comprising:

accessing a vehicle occupant packaging design and a task to be accomplished by a virtual human subject within the design, the virtual human subject comprising a plurality of degrees of freedom, the task comprising an endpoint direction of motion;

accessing a set of constraints limiting how the degrees of freedom of the virtual human subject are manipulated to accomplish the task;

determining a Jacobian between the degrees of freedom and the task during accomplishment of the task, determining the Jacobian comprising determining a manipulation over time of the degrees of freedom of the virtual human subject that accomplishes the task while obeying the set of constraints; and

determining a manipulability metric based on the Jacobian and the endpoint direction of motion, the manipulability metric quantifying a capability of the virtual human subject to manipulate the task along the endpoint direction of motion.

2. The method of claim 1,

wherein the set of constraints comprises a contact constraint preventing motion by the virtual human subject away from a component present in the design;

and

wherein determining the Jacobian comprises prioritizing the contact constraint over accomplishment of the task.

3. The method of claim 1, wherein the set of constraints comprises at least one objective from the group consisting of:

a discomfort objective,

a joint limit objective,

a collision avoidance objective,

a self-penetration avoidance objective; and

wherein determining the Jacobian comprises weighting the manipulation of the degrees of freedom based on the at least one objective.

4. The method of claim 1, wherein determining the Jacobian further comprises:

processing a closed loop inverse kinematics (CLIK) equation comprising a weighting matrix that is weighted by the set of constraints.

5. The method of claim 1, wherein determining the manipulability metric comprises processing a differential kinematics equation including the conjunction with a static equilibrium equation also including the Jacobian.

6. The method of claim 4, wherein the differential kinematics equation provides a mapping between the degrees of freedom of the virtual human subject and the task.

7. The method of claim 4, wherein the static equilibrium equation provides a relationship between a force applied to the task and a torque applied to the degrees of freedom.

8. The method of claim 1, wherein the manipulability metric is an acceleration manipulability metric, and wherein the manipulability metric is further based on at least one of:

a velocity bias term including the effects of accelerations from velocity;

a gravity bias term including the effects of accelerations from gravity; and

at least one joint limit torque for at least one of the degrees of freedom.

9. The method of claim 1, wherein the manipulability metric is a force manipulability metric, and further comprising:

evaluating a feasibility of the design, wherein the design is feasible if the force manipulability metric is above a threshold.

10. The method of claim 1, wherein the manipulability metric is a velocity manipulability metric, and further comprising:

evaluating a feasibility of the design, wherein the design is feasible if the velocity manipulability metric is below a threshold.

11. The method of claim 1, wherein the manipulability metric is an acceleration manipulability metric, and further comprising:

evaluating a feasibility of the design, wherein the design is feasible if the acceleration manipulability metric is above a threshold.

12. A non-transitory computer-readable storage medium containing executable computer program code, the code comprising instructions configured to:

access a vehicle occupant packaging design and a task to be accomplished by a virtual human subject within the design, the virtual human subject comprising a plurality of degrees of freedom, the task comprising an endpoint direction of motion;

access a set of constraints limiting how the degrees of freedom of the virtual human subject are manipulated to accomplish the task;

determine a Jacobian between the degrees of freedom and the task during accomplishment of the task, determining the Jacobian comprising determining a manipulation over time of the degrees of freedom of the virtual human subject that accomplishes the task while obeying the set of constraints; and

determine a manipulability metric based on the Jacobian and the endpoint direction of motion, the manipulability metric quantifying a capability of the virtual human subject to manipulate the task along the endpoint direction of motion.

13. The non-transitory computer-readable storage medium of claim 12,

wherein the set of constraints comprises a contact constraint preventing motion by the virtual human subject away from a component present in the design;

and

wherein determining the Jacobian comprises prioritizing the contact constraint over accomplishment of the task.

14. The non-transitory computer-readable storage medium of claim 12,

processing a closed loop inverse kinematics (CLIK) equation comprising a weighting matrix that is weighted by the set of constraints.

15. The non-transitory computer-readable storage medium of claim 12, wherein determining the manipulability metric comprises processing a differential kinematics equation including the conjunction with a static equilibrium equation also including the Jacobian.

16. The non-transitory computer-readable storage medium of claim 15, wherein the differential kinematics equation provides a mapping between the degrees of freedom of the virtual human subject and the task.

17. The non-transitory computer-readable storage medium of claim 15, wherein the static equilibrium equation provides a relationship between a force applied to the task and a torque applied to the degrees of freedom.

18. A system for comprising:

a processor for executing executable computer program code;

a computer-readable storage medium containing the executable computer program code configured to;

access a vehicle occupant packaging design and a task to be accomplished by a virtual human subject within the design, the virtual human subject comprising a plurality of degrees of freedom, the task comprising an endpoint direction of motion;

access a set of constraints limiting how the degrees of freedom of the virtual human subject are manipulated to accomplish the task;

determine a Jacobian between the degrees of freedom and the task during accomplishment of the task, determining the Jacobian comprising determining a manipulation over time of the degrees of freedom of the virtual human subject that accomplishes the task while obeying the set of constraints; and

determine a manipulability metric based on the Jacobian and the endpoint direction of motion, the manipulability metric quantifying a capability of the virtual human subject to manipulate the task along the endpoint direction of motion.

19. The system of claim 18,

wherein the set of constraints comprises a contact constraint preventing motion by the virtual human subject away from a component present in the design;

and

wherein determining the Jacobian comprises prioritizing the contact constraint over accomplishment of the task.

20. The system of claim 18,

processing a closed loop inverse kinematics (CLIK) equation comprising a weighting matrix that is weighted by the set of constraints.

21. The system of claim 18, wherein determining the manipulability metric comprises processing a differential kinematics equation including the conjunction with a static equilibrium equation also including the Jacobian.

22. The system of claim 21, wherein the differential kinematics equation provides a mapping between the degrees of freedom of the virtual human subject and the task.

23. The system of claim 21, wherein the static equilibrium equation provides a relationship between a force applied to the task and a torque applied to the degrees of freedom.