Brake Pressure Calculation Device for Consistent Deceleration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The coefficient of friction between a brake shoe and a wheel varies with rotational speed and temperature, leading to inconsistent braking force and deceleration, which can diverge from target values, especially when traveling on hills or experiencing changes in gravity.

Innovation Solution

A brake pressure computing apparatus that acquires a target cylinder pressure correction value based on deceleration differential information, allowing for dynamic adjustment of brake cylinder pressure to maintain consistent deceleration, using a system with a target cylinder pressure acquirer, deceleration differential information acquirer, and pressure differential information acquirer to control air pressure in the brake cylinder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the air pressure of the brake cylinder is kept constant, then the device complexity is reduced, but the car deceleration diverges from the target value due to changes in friction coefficient and gravity

Engineering Contradiction:
Improvebrake control system complexityVSAvoiddeceleration control accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The brake control system dynamically adjusts the target cylinder pressure based on real-time deceleration feedback. The controller modifies the pressure command in response to deviations between actual and target deceleration, transforming a static pressure control system into a dynamic one that adapts to changing friction conditions and gravity effects.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements a feedback mechanism where the actual deceleration is measured and compared with the target deceleration. The deceleration differential information is fed back to adjust the target cylinder pressure, creating a closed-loop control system that continuously corrects deviations caused by friction coefficient changes or gravitational effects.

Inventive Principle:
Principle #23Feedback

2Reliability

If the target cylinder pressure is adjusted dynamically based on deceleration feedback, then the deceleration control accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvedeceleration control accuracyVSAvoidbrake control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system changes the control parameter from a fixed target cylinder pressure to a dynamically adjusted one based on deceleration differential information. By modifying the pressure parameter in response to measured deceleration deviations, the system achieves higher control accuracy without requiring complex mechanical adjustments.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution effectively reduces the difference between target and actual deceleration, ensuring consistent braking performance even with varying friction coefficients and environmental conditions, such as hills, by dynamically adjusting brake cylinder pressure.

Implementation Method 1

a brake apparatus that pushes a brake shoe against a wheel to produce braking force

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2669139B1Brake pressure calculation device, brake control system, and program
Publication Date: 2019.03.20 MITSUBISHI ELECTRIC CORP
  • EP2669139B1 patent drawingFigure 1
  • EP2669139B1 patent drawingFigure 2
  • EP2669139B1 patent drawingFigure 3

AI summary

A brake pressure computing apparatus (100) acquires a target cylinder pressure which is a target value of the pressure inside the brake cylinder (104) of an air brake, and is equipped with a target cylinder pressure acquirer (120), a deceleration differential information acquirer (141), and a target cylinder pressure correction value acquirer (142). The target cylinder pressure acquirer (120) acquires a target cylinder pressure on the basis of a required braking force and a target cylinder pressure correction value. The deceleration differential information acquirer (141) acquires deceleration differential information indicating the difference between the target value of the deceleration and the actual value of the deceleration. The target cylinder pressure correction value acquirer (142) acquires the target cylinder pressure correction value on the basis of the deceleration differential information.