Bolstering Driver Braking Confidence Considerations for "Deceleration Adder" Technologies General Motors LLC

Format:

Book

Conference/Event

Author/Creator:

Antanaitis, David, author.

Conference Name:

Brake Colloquium & Exhibition - 43rd Annual (2025-09-21 : Grand Rapids, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2025

Summary:

Over the life of a typical vehicle (often estimated as 15 years or 300,00 km), an average driver can be expected to apply the brakes about 1.6 million times almost 9 times per mile and over 290 times per day, and an "exuberant" driver can be expected to do this over 2.2 million times. Without question, the driver becomes accustomed to how the vehicle responds to braking control (and all of the normal variation around it), and even develops expectations for how it will respond the next time the brakes are employed. In the rare event of a failure or malfunction in the brake system resulting in an appreciably different vehicle response to the brake input, this can be surprising and even alarming to the driver, sometimes to the extent of causing hesitation in braking. Fortunately, with the rise of mechatronic braking actuators in the 1980's and 1990's paved the way for features such as "Driver Brake Assist" (which provides additional pressure beyond what the primary brake actuator can at the time) and "Panic Brake Assist" (which provides additional pressure beyond what the driver is requesting, when the brake apply rate is above a calibratable threshold) to be developed. These features used the new (at the time) brake actuator, the hydraulic pump in the anti-lock brake unit, to provide additional assist to the driver if needed. Vehicles of today will often have multiple actuators capable of providing deceleration, including a mechatronic (or vacuum) brake booster, regenerative braking, electric parking brake actuators, and in some cases a secondary brake module. With these added degrees of freedom, comes added opportunity to improve performance and therefore the driver's confidence in the vehicle's braking capability, but also added complexity. With actuators able to increase - depending on their installation - braking on the front axle, the rear axle, or both, and with the ability to suppress hydraulics via valve control to reduce pedal travel, important considerations for brake balance and vehicle stability arise, which must be balanced with straight line performance and brake feel. The present work briefly examines the history of "deceleration adders" (supplemental brake actuators used to improve performance in certain operating conditions such as system failures), draws from published information to establish a framework for the performance necessary to maintain the driver's confidence, and discusses different actuator types and control strategies along with considerations for integrating them into the brake system

Notes:

Vendor supplied data

Publisher Number:

2025-01-0353

Access Restriction:

Restricted for use by site license