Motor amplifier and control for a personal transporter

• US 6,288,505 B1
• Filed: 12/18/2000
• Issued: 09/11/2001
• Est. Priority Date: 10/13/2000
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Morrell, John B., Heinzmann, John David, Yundt, George B.
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US09/739,192
• Time in Patent Office: 267 Days
• Field of Search: 318/580, 318/586, 318/587, 318/625, 318/53, 318/59, 318/66, 318/105, 318/106, 318/112, 318/139, 318/268, 318/500, 180/180, 180/181, 180/21, 180/218, 180/171, 180/209, 701/82, 701/22
• US Class Current: 318/139
• CPC Class Codes: A63C 17/12 with driving mechanisms
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B62K 11/007 Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for controlling a motorized balancing transporter that has two wheels in contact with the ground in normal operation. A signal substantially proportional to the shaft velocity is produced, and, at a rate less than 200 times per second, a voltage is calculated based at least on the shaft velocity signal and a specified transporter velocity and a voltage is applied to the motor based on the calculated voltage. A method is also provided for yaw control of the motorized balancing transporter that includes calculating a command to a motor amplifier based on balancing requirements of the transporter and augmenting the command to the motor amplifier based on a specified direction of motion.

Claims

1. A method for controlling an electrical motor in a balancing transporter, the transporter having precisely two wheels in contact with the ground in normal operation and having a balancing controller characterized by a frame rate, the electric motor driving a shaft for coupling power to one of the precisely two wheels, the shaft characterized by an instantaneous shaft velocity, the method comprising:

(a) controlling the output of the power stage by means of an inner loop characterized by a first bandwidth;

(b) producing a signal substantially proportional to the shaft velocity in response to the output of the power stage;

(c) calculating, at a rate equal to the frame rate and less than one third of the first bandwidth, a voltage command signal based at least on the shaft velocity signal and a specified transporter velocity; and

(d) controlling a voltage applied to the motor based on the voltage command signal.

2. A method in accordance with claim 1, further including the step of providing the specified transporter velocity by means of a user input device.

3. A method in accordance with claim 1, wherein the step of producing a signal substantially proportional to the shaft velocity includes differentiating a signal from a shaft position sensor.

4. A velocity controller for a balancing personal transporter, the velocity controller comprising:

(a) a motor having a shaft for driving a wheel of the balancing personal vehicle;

(b) a motor amplifier for supplying power to the motor, the amplifier controlled at a rate characterized by an inner loop bandwidth;

(c) a shaft feedback sensor for measuring angular velocity of the shaft and providing a shaft velocity signal;

(d) a user input for receiving specification of a commanded vehicle velocity;

(e) a controller for calculating, at a rate less than one third of the inner loop bandwidth, a voltage command signal based at least on the shaft velocity signal and the commanded transporter velocity; and

(f) an amplifier for applying a voltage based on the voltage command signal across the motor.

5. A method for controlling the yaw of a motorized balancing transporter having precisely two laterally disposed wheels, each wheel being actuated by a motor, each motor being driven by a motor amplifier, the method comprising:

(a) calculating a command to a motor amplifier based on balancing requirements of the transporter;

(b) augmenting the command to the motor amplifier based on a specified direction of motion;

(c) generating an amplifier output based in part on the augmented command;

(d) sensing the amplifier output;

(e) modifying the command based on the amplifier output; and

(f) applying the amplifier output to a wheel motor.

6. The method of claim 5 wherein the amplifier output is a voltage.

7. A method of claim 5 further comprising the steps of:

(g) sensing a velocity of each wheel; and

(h) modifying the command to each of two wheel amplifiers based on the wheel velocities.