A Method to Capture and Analyze Brake Dynamic Drag 2021-26-0477

At present, all automobile manufacturers are fighting climate change through various emission reduction approach. In vehicle Brake system, one of the major factor which contributes to vehicle tail pipe emission in residual brake drag. A residual brake drag shall be defined as the resistance torque produced by brake in brake released condition. In Caliper brake assemblies which is a commonly used foundation brake, to reduce residual drag, low drag caliper is used. Low drag in caliper is achieved using positive retraction clip and increased caliper piston seal roll back. In general residual drag is measured in static test condition and there is no standard test procedure to assess residual drag in dynamic condition. Vehicle manufactures pays higher price for this low drag caliper owing to its benefit towards vehicle emission reduction. However, the current assessment method of running vehicle back to back in same condition with and without low drag caliper and evaluate fuel efficiency is not proven to be accurate and useful.

In the present work, a novel data based approach has been developed to estimate dynamic drag of foundation brake using brake dynamometer. This approach allows us to capture, analyze and compare dynamic drag of a foundation brake say a caliper under any tests such as wear test, performance test etc. This is done by capturing drag data in dynamometer and synchronizing this data with actual test stops. The Non-brake zone is segregated and analyzed to study the dynamic drag. A MATLAB based data processing tool is developed to perform above mentioned tasks. The approach and tool enables the user to determine the effect of drag in terms of work done and also compare with the other brake. With this approach, low drag caliper proposals shall be assessed for its fuel efficiency improvement with more accuracy.