Brake control device for electric vehicle

• US 8,010,271 B2
• Filed: 05/30/2007
• Issued: 08/30/2011
• Est. Priority Date: 05/30/2007
• Status: Active Grant

• Current Assignee: Nexgen Control Systems LLC
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Harada, Ryotaro
• Primary Examiner(s): Boehler; Anne Marie M
• Assistant Examiner(s): ARCE, MARLON ALEXANDER
• Application Number:
  US12/159,478
• Publication Number:
  US 20100049416A1
• Time in Patent Office: 1,553 Days
• Field of Search: 701/81, 701/83, 701/78, 701/71, 477/182, 180/65.1, 180/65.265, 180/65.285, 180/65.31, 903/947, 903/930
• US Class Current: 701/81
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60T 13/665 the systems being specially adapted for transferring two or more command signals, e.g. railway systems B60T13/662 takes precedence
• CPC Class Codes: B60T 13/746 and mechanical transmission of the braking action
• CPC Class Codes: B60T 17/228 for railway vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements
• CPC Class Codes: Y10S 903/947 Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A brake control device for an electric vehicle includes an instruction controller, a pattern generator, and comparators. The instruction controller generates an instruction signal for instructing a motor about electric brake force. The pattern generator generates a first pattern signal for changing over electric brake force to machine brake force and a second pattern signal obtained by shifting the first pattern signal by a predetermined frequency. One of the comparators outputs, as an electric-brake force pattern, smaller one of the instruction signal and the first pattern signal. The other of the comparators outputs, as a notification signal, a signal output when the second pattern signal becomes equal to or smaller than the instruction signal.

Claims

1. A brake control device for an electric vehicle, comprising:

a motor controller that outputs a motor control signal for controlling at least one motor that drives the electric vehicle;

an electric brake controller that outputs a brake-force signal indicating electric brake force generated by the motor, and a notification signal for notifying, at a defined time before, that an electric brake is to be released; and

a machine brake controller that controls total force consisting of electric brake force and machine brake force based on the brake-force signal and the notification signal, wherein

the electric brake controller includes

an electric-brake-force instruction controller that generates an instruction signal for instructing the motor with respect to electric brake force;

a comparison pattern generator that generates a first pattern signal for, while reducing electric brake force to zero at a closing speed of the electric brake, changing over the electric brake force to machine brake force, and a second pattern signal obtained by shifting the first pattern signal by a predetermined frequency to a side on which motor frequency increases;

a first comparator that compares the instruction signal with the first pattern signal, and outputs, as an electric-brake force pattern, a smaller one of the instruction signal and the first pattern signal to the motor controller; and

a second comparator that compares the instruction signal with the second pattern signal, and outputs, as the notification signal, a signal output at a timing when the second pattern signal becomes equal to or smaller than the instruction signal to the machine brake controller.

2. The brake control device according to claim 1, wherein the predetermined frequency by which the first pattern signal is shifted is calculated based on a position of a master controller of the electric vehicle.

3. The brake control device according to claim 1, wherein the comparison pattern generator includes

a first reference table for calculating electric brake force of the motor corresponding to operation frequency of the motor;

and

a second reference table for calculating an amount of change in electric brake force corresponding to a position of a master controller of the electric vehicle as the predetermined frequency by which the first pattern signal is shifted, wherein

the comparison pattern generator outputs, as the second pattern signal, a signal obtained by subtracting a value of output calculated by the second reference table from a value of output calculated by the first reference table to the second comparator.