Vehicle having independently driven and controlled right and left drive wheels

Patent metadata

Field	Value
Publication number	US-10293853-B2
Application number	US-201715490157-A
Country	US
Kind code	B2
Filing date	Apr 18, 2017
Priority date	Jun 15, 2011
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A self-propelled vehicle includes a maneuvering unit, a drive unit including first and second drive sections, which are driven and controlled by drive wheel control commands, a drive wheel unit including left and right drive wheels driven by the first and second drive sections, respectively, at least one caster wheel which is controlled by a caster wheel control command, a bank detector for detecting a degree of bank of the vehicle and a control unit including a drive wheel control section for generating the drive wheel control commands. The control unit further includes a caster wheel control section which generates the caster wheel control command for controlling the steering angle of the caster wheel during a bank traversing travel, based on the bank degree so as to resolve a difference between a target travel and the actual travel which occurs during the bank traversing travel.

First claim

The invention claimed is:

1. A self-propelled vehicle comprising:
a vehicle body;
a maneuvering unit mounted on the vehicle body and operated by a driver aboard on the vehicle body;
a drive unit including a first drive section and a second drive section which are driven and controlled independently of each other by respective drive wheel control commands;
a drive wheel unit including a left drive wheel driven for traveling by the first drive section and a right drive wheel driven for traveling by the second drive section;
at least one caster wheel which is controlled in a steering angle thereof by a caster wheel control command;
a bank detector for detecting a degree of bank of the vehicle; and
a control unit including a drive wheel control section for generating said drive wheel control commands based on an operational amount of the maneuvering unit, said control unit further including a caster wheel control section which generates the caster wheel control command for controlling the steering angle of the caster wheel: α=Q(θ) during bank-traversing of the vehicle, based on said degree of bank: θ (=roll angle) during the bank-traversing of the vehicle so as to cancel out an inclinedly downwardly turning tendency occurring on the caster wheel.

2. A self-propelled vehicle according to claim 1 , wherein:
said at least one caster wheel includes a left caster wheel and a right caster wheel; and
the vehicle further comprises a caster wheel drive section for driving the caster wheel for traveling,
wherein said caster wheel control section generates a caster wheel rotation control command based on said degree of bank: θ during the bank-traversing of the vehicle, and
wherein said caster wheel drive section outputs a caster driving torque: Z=F(θ) based on said caster wheel rotation control command so as to cancel out the inclinedly downwardly turning tendency occurring on the caster wheel.

3. A self-propelled vehicle according to claim 1 , wherein the drive unit and the caster wheel drive section are constituted of electric motors.

4. A self-propelled vehicle according to claim 2 , wherein said caster wheel control command and/or said caster wheel rotation control command are/is outputted based on an operation of a manual operational tool.

5. A self-propelled vehicle comprising:
a vehicle body;
a maneuvering unit mounted on the vehicle body and operated by a driver aboard on the vehicle body;
a control unit for generating a control amount for changing a travel speed and a travel direction of the vehicle, based on an operational amount of the maneuvering unit;
a pair of left and right freely steerable caster wheels;
a drive unit including a first drive section and a second drive section which are driven and controlled independently of each other by said control amount;
a drive wheel unit including a left drive wheel driven for traveling by the first drive section and a right drive wheel driven for traveling by the second drive section, the travel direction being changed by a rotation difference between the left drive wheel and the right drive wheel;
a bank detector for detecting a degree of bank of the vehicle and outputting it to said control unit; and
a caster wheel drive section for driving the caster wheel for traveling;
wherein said control unit includes:
a drive torque calculation section for calculating drive torque required for said first drive section and said second drive section;
a compensation torque calculation section for calculating a compensation torque for resolving a travel direction difference between a target travel direction and an actual travel direction in a bank travel, for said first drive section and said second drive section based on said bank degree;
a correction section for correcting said control amount based on said required drive torque and said compensation torque; and
a caster wheel control section, wherein said caster wheel control section generates a caster wheel rotation control command based on said degree of bank: θ (=roll angle) during the bank-traversing of the vehicle, and wherein said caster wheel drive section outputs a caster driving torque: Z=F(θ) based on said caster wheel rotation control command so as to cancel out an inclinedly downwardly turning tendency occurring on the caster wheel.

6. A self-propelled vehicle according to claim 5 ,
wherein said caster wheel control section controls a steering angle of the caster wheel during the bank travel, based on said bank degree so as to resolve the travel direction difference.

7. A self-propelled vehicle comprising:
a vehicle body;
a maneuvering unit mounted on the vehicle body and operated by a driver aboard on the vehicle body;
a drive unit including a first drive section and a second drive section which are driven and controlled independently of each other by respective drive wheel control commands;
a drive wheel unit including a left drive wheel driven for traveling by the first drive section and a right drive wheel driven for traveling by the second drive section;
a pair of left and right caster wheels which is controlled in a steering angle thereof by a caster wheel control command;
a bank detector for detecting a degree of bank of the vehicle;
a caster wheel drive section for driving the caster wheel for traveling; and
a control unit including a drive wheel control section for generating said drive wheel control commands based on an operational amount of the maneuvering unit, said control unit further including a caster wheel control section, wherein said caster wheel control section generates a caster wheel rotation control command based on said degree of bank: θ (=roll angle) during the bank-traversing of the vehicle, and wherein said caster wheel drive section outputs a caster driving torque: Z=F(θ) based on said caster wheel rotation control command so as to cancel out an inclinedly downwardly turning tendency occurring on the caster wheel.

8. A self-propelled vehicle according to claim 1 , wherein:
said caster wheel includes a left caster wheel and a right caster wheel; and
the steering angle of the left caster wheel: αL=QL(θ) and the steering angle of the right caster wheel: αR=QR(θ), each controlled by the caster wheel control command, are calculated by equations that are independent of each other.

Assignees

• Kubota Kk

Inventors

• Koike Kazuo
• Ito Hirokazu
• Togoshi Yoshikazu

Classifications

• B62D6/04 Primary

  responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel · CPC title

• B60L15/36

  with automatic control superimposed, e.g. to prevent excessive motor current · CPC title

• B62D11/003

  Electric or electronic control systems · CPC title

• Y02T10/645

  Cross-Sectional Technologies · mapped topic

• A01D34/006

  Control or measuring arrangements · CPC title