Gm Global Technolgoy Operations, Inc.

Margaret C Richards

Patrick J Monsere

Jon K Logan

Danny Y Mui

Lan Wang

Zhong Wang

Tony T Hoang

Daryl A Wilson

Wenbo Wang

Kevin S Kidston

Brandon R Jones

Jonathan King

Matthew S Stout

Cody D Berman

Ryan M Ashby

Tony Wingett

A system of selecting charging modes for a rechargeable energy storage unit in an autonomous device includes a controller having a processor and tangible, non-transitory memory on which is recorded instructions. The controller is configured to determine availability of at least one charging station and at least one parking lot through a survey of local charging infrastructure and local parking infrastructure, respectively, within a predefined radius of the autonomous device. The controller is configured to determine if it is cost-effective during an excursion to incur a charging fee at the charging station or incur a parking fee at the parking lot. If it is cost-effective to incur the charging fee, then the controller is configured to selectively employ at least one of a plurality of charging modes, including an open-ended charging mode and a defined departure charging mode.

Selection of charging modes for autonomous device

A method that compensates for fluid pressure variations in a vehicle brake system so that the fluid pressure, brake torque and/or brake force at the wheel more accurately reflects that requested by the driver. In an exemplary embodiment, the method determines the braking intent of the driver, determines a current stage of the braking event (e.g., an apply stage, release stage, etc.), uses the braking event stage and the driver braking intent to select a pressure compensation, and uses the pressure compensation to generate compensated brake command signals for operating the vehicle brake system. This method is well suited for use with brake-by-wire systems, such as an electrohydraulic braking (EHB) system.

Method for operating a vehicle brake system

A control system for evaluating a brake booster system includes an engine evaluation module that detects an engine off condition. A pressure evaluation module, during the engine off condition, monitors hydraulic brake line pressure, detects a change in brake booster pressure, and determines a brake booster vacuum decay rate based on the change in brake booster pressure. A fault reporting module detects a brake booster system fault based on the brake line pressure and the brake booster vacuum decay rate.

Brake booster leak detection system

A method that compensates for temperature-related effects in a vehicle brake system. According to one embodiment, the method determines the temperature of a brake pad, calculates a temperature-based modifier, and then uses the temperature-based modifier to adjust one or more brake command signals provided to the vehicle brake system so that they are compensated for temperature-related changes in the coefficient of friction (&#x3bc;) of the brake pad and rotor. The method may be used with brake-by-wire systems such as electrohydraulic braking (EHB) systems and electromechanical braking (EMB) systems.

Method for operating a vehicle brake system using brake temperature

A leak diagnostic system for a vehicle comprises a calculation module and a diagnostic enabling module. The calculation module calculates a decay rate of a brake booster vacuum. The diagnostic enabling module selectively enables the decay rate calculation based on mass airflow (MAF) into an engine and engine vacuum.

Braking booster system leak diagnostics

A method for controlling braking in a vehicle having a brake pedal includes the steps of obtaining a first measure of braking intent based on movement of the brake pedal, obtaining a second measure of braking intent based on a force applied to the brake pedal, controlling the braking based on the first measure provided that a transition parameter is less than a first predetermined value, controlling the braking based on the second measure provided that the transition parameter is greater than a second predetermined value, and controlling the braking based on the first measure and the second measure provided that the transition parameter is greater than the first predetermined value and less than the second predetermined value.

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Royal Oak, MI, United States of America

Margaret C Richards