Method for adaptive control of human-machine systems employing disturbance response

• US 5,555,495 A
• Filed: 10/25/1993
• Issued: 09/10/1996
• Est. Priority Date: 10/25/1993
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Bell, David A., Levine, Simon, Bell, Lon E., Koren, Yoram
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): BROWN, THOMAS
• Application Number:
  US08/142,208
• Time in Patent Office: 1,051 Days
• Field of Search: 364/148, 364/149, 364/158, 364/160-167.01, 364/176, 364/180, 364/190, 364/425, 364/424.03, 395/21, 395/22, 395/23, 395/61, 395/80, 395/81, 395/87, 395/88, 395/92, 395/903-905, 901/3-5, 180/907, 280/250.1, 280/304.1, 279/DIG. 4
• US Class Current: 700/38
• CPC Class Codes: A61G 2203/14 Joysticks
• CPC Class Codes: A61G 5/04 motor-driven A61G5/06 takes precedence; motor-operated rests A61G5/12; for vehicles with handlebars, equipped with three or more wheels B62K5/003, B62K5/023
• CPC Class Codes: B60W 40/08 related to drivers or passengers
• CPC Class Codes: Y10S 180/907 Motorized wheelchairs
• CPC Class Codes: Y10S 297/04 Wheelchair
• CPC Class Codes: Y10S 706/905 Vehicle or aerospace

Abstract

Adaptive control of a system with a human in the loop is accomplished by sensing human operator reactions to a disturbance in the system and characterizing the operator response to the disturbance. The operator response is characterized in one of several forms by predicting a response based on a model quantifying a response based on statistics or merely measuring a response for accumulation of data to be employed by an artificial intelligent system. The disturbance which provides the human operator reaction, is applied or occurs naturally based on other stimulus and is measured by the system. Quantifying the results of the disturbance and the operator response comparison allows selection of a control mode by identifying one or more categories of reaction response or a graduated modification of the control law employed in the system. Various modes or categories for control of the system incorporate different sensitivities on a macro scale or an entirely different control algorithm. Graduated adaptation alters sensitivity or other perimeters in the system at a micro level incrementally throughout given ranges of control.

Claims

1. An adaptive control method for human in the loop systems comprising the steps of:

(a) sensing human operator reaction to a disturbance in a control system;

(b) characterizing an operator response to the disturbance;

(c) comparing the operator reaction and the characterized response to produce a result;

(d) modifying an initial control law based on the result of the comparison to create a modified control law; and

(e) creating a control signal based on the modified control law.

2. A method as defined in claim 1, further comprising of the initial steps of:

(a) calculating a disturbance to be applied to the system; and

(b) applying the calculated disturbance to the system wherein the disturbance of the sensing step comprises the calculated disturbance.

3. A method as defined in claim 1, further comprising the initial step of measuring a disturbance in the system created by external stimulus, and wherein the disturbance of the sensing step comprises the measured disturbance.

4. A method as defined in claim 1, further comprising the initial step of measuring a disturbance in the system created by stochastic perturbation in the system, and wherein the disturbance of the sensing step comprises the measured disturbance.

6. A method as defined in claim 1, wherein characterizing an operator response to the disturbance comprises the steps of:

(a) measuring the response;

(b) storing the measurement in a database;

(c) acting on the database with an artificial intelligence system; and

(d) providing an output from the artificial intelligence system which characterizes the response.

7. A method as defined in claim 1, wherein characterizing an operator response to the disturbance comprises:

(a) preparing a model of human response characteristics based on an initial control law;

(b) predicting human operator response to the disturbance using the initial control law; and

wherein the characterized response comprises the predicted response.

8. A method as defined in claim 1, wherein characterizing an operator response employs a neural network.

9. A method as defined in claim 1, wherein the step of creating a control signal employs Bayesian modeling techniques.

5. An adaptive control method for human in the loop systems comprising the steps of:

(a) sensing human operator reaction to a disturbance in a control system;

(b) characterizing an operator response to the disturbance;

(c) comparing the operator reaction and the characterized response to produce a result;

(d) quantifying the comparison into at least two categories;

(e) identifying the category into which the result of the comparison falls;

(f) selecting a control law based on the category identified; and

(g) issuing control commands to the system using the selected control law.

10. An adaptive control method for a motorized wheelchair having a joystick control input and motorized wheel control comprising the steps of:

(a) applying a disturbance to the joystick;

(b) sensing human operator reaction to the disturbance applied;

(c) characterizing operator response to the disturbance;

(d) comparing the operator reaction and the characterized response to produce a result; and

(e) selecting a wheelchair operating mode based on the result of the comparison.

11. An adaptive control method for a motorized wheelchair having a joystick control input and motorized wheel control comprising the steps of:

(a) applying a disturbance to the motorized wheel control;

(b) sensing human operator reaction to the disturbance applied;

(c) characterizing operator response to the disturbance;

(d) comparing the operator reaction and the characterized response to produce a result; and

(e) selecting a wheelchair operating mode based on the result of the comparison.

12. A operator impairment testing method comprising the steps of:

(a) measuring a disturbance to a control system operated by the operator in an vehicle;

(b) sensing operator reaction to the disturbance;

(c) characterizing an operator response to the disturbance;

(d) comparing the operator'"'"'s reaction and the characterized response to identify a reaction inconsistent with the characterized response; and

(e) activating an output when an abnormal reaction is detected.

13. An adaptive control method for a vehicle having a manual control input device and motorized wheel control comprising the steps of:

(a) applying a disturbance to the manual control input device;

(b) sensing human operator reaction to the disturbance applied;

(c) characterizing operator response to the disturbance;

(d) comparing the operator reaction and the characterized response to produce a result; and

(e) selecting a vehicle operating mode based on the result of the comparison.

14. An adaptive control method for a vehicle having a manual control input device and motorized wheel control comprising the steps of:

(a) applying a disturbance to the motorized wheel control;

(b) sensing human operator reaction to the disturbance applied;

(c) characterizing operator response to the disturbance;

(d) comparing the operator reaction and the characterized response to produce a result; and

(e) selecting a vehicle operating mode based on the result of the comparison.