Anti-rollback system for an electric motor and method therefor

• US 6,731,084 B2
• Filed: 10/15/2002
• Issued: 05/04/2004
• Est. Priority Date: 10/18/2001
• Status: Expired due to Fees

• Current Assignee: Liber-T Medtech, Inc.
• Original Assignee: Liber-T Medtech, Inc.
• Inventors: Gagnon, Eric, Cliche, Thomas
• Primary Examiner(s): Masih, Karen
• Application Number:
  US10/281,044
• Publication Number:
  US 20030117096A1
• Time in Patent Office: 567 Days
• Field of Search: 318/372, 318/139, 318/67, 318/587, 318/369, 318/269, 318/280, 318/445, 318/63, 318/86, 318/757, 180/65
• US Class Current: 318/372
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The present method and system allows minimization of a rollback effect when an electric vehicle, such as a wheelchair, brakes on a slope. The system comprises secondary brake, a controller, and a monitor that allows to apply both a control voltage and the secondary brakes according to an appropriate sequence to provide stops and starts with a minimized rollback effect. An updated armature resistance value is advantageously used to take into account evolutive conditions of the vehicle.

Claims

1. A method for managing stops of a wheel driven by an electric motor using a secondary brake, said method comprising:

providing the secondary brake application time;

upon receiving a stop triggering signal;

controlling the electric motor so as to bring the wheel to a stop;

applying said secondary brake;

waiting at least a period of time corresponding to said secondary brake application time while collecting data related to the voltage applied during the braking and removing voltage from the electric motor; and

upon receiving a start triggering signal;

using said collected data to apply on the electric motor about said voltage applied during braking;

removing said secondary brake; and

controlling the electric motor so as to bring power to the wheel.

2. A method as recited in claim 1, further comprising:

using an updated armature resistance value while controlling the electric motor and applying voltage thereto.

3. A system for managing stops of a wheel driven by an electric motor, said system comprising:

a controller to be connected to the electric motor;

a secondary brake for selectively stopping the wheel;

said secondary brake having a brake application time;

a monitoring device connected to both said controller and the electric motor;

said controller being configured for,

upon receiving a stop triggering signal;

controlling the electric motor so as to bring the wheel to a stop;

applying said secondary brake;

waiting at least a period of time corresponding to said secondary brake application time while collecting data related to the voltage applied during the braking and removing voltage from the electric motor; and

upon receiving a start triggering signal;

using said collected data to apply on the electric motor about said voltage applied during braking;

removing said secondary brake; and

controlling the electric motor so as to bring power to the wheel.