Chassis Dynamometer Braking Force Control via Driven Wheel Feedback

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Solution Overview

Problem

Conventional chassis dynamometers require excessive operating force on brakes to simulate deceleration in two-wheel drive vehicles, leading to brake overheating and tire damage, and necessitate complex preliminary settings for each vehicle type, burdening operators.

Innovation Solution

A chassis dynamometer with a driving wheel side power absorbing part and a braking force measuring part that sets the control target value for the driving wheel side power absorbing part using measured braking force, reducing the operating force on brakes and eliminating the need for preliminary braking force settings for each vehicle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If large operating force is applied to driving wheel side brakes to achieve desired deceleration, then deceleration performance is improved, but brake overheating and tire damage occur

Engineering Contradiction:

Improvedeceleration rateVSAvoidbrake temperature

Core Design Contradiction:

SpeedVSTemperature

Solution Approach 1:

The braking function is segmented between two independent braking systems: driven wheel side brakes and driving wheel side brakes. The driven wheel side brakes handle primary deceleration while the driving wheel side brakes provide secondary braking, distributing the thermal load and preventing overheating of any single brake system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The driven wheel side roller acts as an intermediary power absorbing component that converts kinetic energy to thermal energy through controlled friction, serving as a mediator that reduces the burden on the driving wheel side brakes and prevents their overheating.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If large operating force is applied to driven wheel side brakes to achieve desired deceleration, then deceleration performance is improved, but brake lock-up and tire damage occur

Engineering Contradiction:

Improvedeceleration rateVSAvoidbrake control stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The driven wheel side brakes apply partial braking force rather than full braking force, with the driving wheel side brakes providing supplementary braking. This partial action approach prevents excessive braking force that would cause lock-up while still achieving the desired deceleration rate.

Inventive Principle:

Principle #16Partial or excessive action

3Ease of operation

If preliminary braking force settings are made for each vehicle type to reduce operating force, then operator burden is reduced, but setting complexity increases

Engineering Contradiction:

Improveoperator burdenVSAvoidbraking force setting complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The chassis dynamometer system automatically determines and adjusts braking forces based on vehicle characteristics and test conditions without requiring manual preliminary settings by operators. The control unit performs self-service by calculating appropriate braking forces and adjusting the braking systems accordingly, eliminating complex setup procedures.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system uses feedback from sensors measuring vehicle parameters, braking force, and roller speed to automatically adjust braking forces during testing. This closed-loop control eliminates the need for manual preliminary settings while maintaining optimal braking performance across different vehicle types.

Inventive Principle:

Principle #23Feedback

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

The solution allows for accurate simulation of actual road runs with reduced brake operating force, minimizing heat generation and operator burden, and eliminating the need for complex preliminary settings.

Implementation Method 1

not only on the driving wheel side, but operating force exerted on the driven wheel side brakes is increased to increase a calorific value

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

a braking force measuring part that measures braking force exerted on the driven wheel side roller

Methodology Applied

Scientific EffectTorque: Torque

Data Source

PatentEP3591368B1Chassis dynamometer, control method for the same, and chassis dynamometer program

Publication Date: 2023.03.22 HORIBA LTD

Figure 1

AI summary

The present invention is one that allows a chassis dynamometer, which tests two-wheel drive vehicle, to accurately reproduce an actual road run. A chassis dynamometer 100 that tests a two-wheel drive vehicle 10 includes: a driving wheel side roller 2 on which the driving wheels 11 of the vehicle 10 are placed; a driven wheel side roller 3 on which the driven wheels 12 of the vehicle 10 are placed; a driving wheel side power absorbing part 4 connected to the driving wheel side roller 2; a driven wheel side power absorbing part 5 connected to the driven wheel side roller 3; a braking force measuring part 8 that, via the driven wheel side power absorbing part 5, measures braking force exerted on the driven wheel side roller 3; and a control part 6 that with use of the braking force measured by the braking force measuring part 8, sets the control target value of the power absorbing force of the driving wheel side power absorbing part 4 to control the driving wheel side power absorbing part 4.