Operating modes for stair climbing in a cluster-wheel vehicle

• US 6,343,664 B2
• Filed: 01/09/2001
• Issued: 02/05/2002
• Est. Priority Date: 03/15/1999
• Status: Expired due to Term

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: Deka Products Limited Partnership
• Inventors: Morrell, John B., Kerwin, John M.
• Primary Examiner(s): Hurley, Kevin
• Application Number:
  US09/757,230
• Publication Number:
  US 20010001992A1
• Time in Patent Office: 392 Days
• Field of Search: 180/8.1, 180/8.2, 180/8.3, 180/65.1, 180/65.8, 701/36, 701/37, 701/38, 701/48, 701/65
• US Class Current: 180/8.2
• CPC Class Codes: A61G 2203/14 Joysticks
• CPC Class Codes: A61G 2203/46 for temperature
• 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: A61G 5/061 for climbing stairs
• CPC Class Codes: B60K 7/00 Disposition of motor in, or adjacent to, traction wheel roller-skate driving mechanisms A63C17/12
• CPC Class Codes: B62D 57/00 Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track sledges B62B; motor sledges B62M
• CPC Class Codes: G05B 13/042 in which a parameter or coefficient is automatically adjusted to optimise the performance

Abstract

A method for operating a device ascending or descending stairs. The device has a plurality of wheels rotatable about axes that are fixed with respect to a cluster arm, where the cluster arm itself is rotated about an axis so that wheels rest on successive stairs. The wheels and cluster arms are controlled according to separate control laws by a controller. Whether the device ascends or descends the stairs is governed by the pitch of the device relative to specified front and rear angles.

Claims

1. A method for governing motion on stairs of a device, the device characterized by an instantaneous pitch angle and having a plurality of wheels, each wheel rotatable about an axis fixed with respect to a cluster arm, the cluster arm rotatable about a cluster axis, the method comprising:

a. setting a front angle and a rear angle defined with respect to a vertical direction;

b. actuating the cluster arm to provide descent of the device if the instantaneous pitch exceeds the front angle; and

c. actuating the cluster arm to provide ascent of the device if the instantaneous pitch is less than the rear angle.

2. A method according to claim 1, wherein the step of setting a front angle and a rear angle includes changing at least one of the front angle and rear angle on the basis of the cluster angle.

3. A method according to claim 1, further comprising:

d. monitoring a sensor signal characterizing the temperature of the cluster arm; and

e. engaging a brake for braking the cluster arm when the sensor signal exceeds a preset threshold so as to allow the cluster arm to rotate freely in such a manner that the device assumes a statically stable configuration on the stairs.

4. A method according to claim 1, further comprising:

d. monitoring the temperature of the actuator;

e. detecting an over-temperature condition; and

f. limiting the cluster actuator load by allowing cluster rotation only in the direction of descent for the duration of the over-temperature condition.