Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, gear ratios on vehicles. A front vehicle can shift a gear which, via a vehicle-to-vehicle communication link, can cause a rear vehicle to shift gears. To maintain a gap, vehicles may shift gears at various relative positions based on a grade of a road.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, gear ratios on vehicles. A front vehicle can shift a gear which, via a vehicle-to-vehicle communication link, can cause a rear vehicle to shift gears. To maintain a gap, vehicles may shift gears at various relative positions based on a grade of a road.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, gear ratios on vehicles. A front vehicle can shift a gear which, via a vehicle-to-vehicle communication link, can cause a rear vehicle to shift gears. To maintain a gap, vehicles may shift gears at various relative positions based on a grade of a road.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, gear ratios on vehicles. A front vehicle can shift a gear which, via a vehicle-to-vehicle communication link, can cause a rear vehicle to shift gears. To maintain a gap, vehicles may shift gears at various relative positions based on a grade of a road.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, relative distance, relative acceleration or deceleration, and speed. In some aspects, a lead vehicle can wirelessly transmit information from various electronic control units (ECUs) to ECUs in a rear vehicle. A rear vehicle can then apply transformations to the information to account for a desired following distance and a time offset. ECUs onboard the rear vehicle may then be controlled based on the ECUs of the lead vehicle, the desired following distance, and the time offset.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, relative distance, relative acceleration or deceleration, and speed. In some aspects, a lead vehicle can wirelessly transmit information from various electronic control units (ECUs) to ECUs in a rear vehicle. A rear vehicle can then apply transformations to the information to account for a desired following distance and a time offset. ECUs onboard the rear vehicle may then be controlled based on the ECUs of the lead vehicle, the desired following distance, and the time offset.

Abstract: Systems and methods for coordinating and controlling vehicles, for example heavy trucks, to follow closely behind each other, or linking to form a platoon. In one aspect, on-board controllers in each vehicle interact with vehicular sensors to monitor and control, for example, gear ratios on vehicles. A front vehicle can shift a gear which, via a vehicle-to-vehicle communication link, can cause a rear vehicle to shift gears. To maintain a gap, vehicles may shift gears at various relative positions based on a grade of a road.

Abstract: A microvalve device for controlling fluid flow includes a body defining a chamber having first and second ends. The first end is in communication with a source of command pressure. The second end in communication with a source of load pressure. A micromachined spool valve is disposed in the chamber between the first and second ends for sliding movement by differential pressure across the spool between a first position in which allows fluid flow between the source of load pressure and a source of supply pressure and a second position which allows fluid flow between the source of load pressure and a pressure vent. The spool valve has a closed position intermediate the first position and the second position which restricts fluid flow between the source of load pressure and both the source of supply pressure and the pressure vent. The spool valve is moveably connected to the body.

Abstract: A microvalve device for controlling fluid flow includes a body defining a chamber having first and second ends. The first end is in communication with a source of command pressure. The second end in communication with a source of load pressure. A micromachined spool valve is disposed in the chamber between the first and second ends for sliding movement by differential pressure across the spool valve between a first position in which allows fluid flow between the source of load pressure and a source of supply pressure and a second position which allows fluid flow between the source of load pressure and a pressure vent. The spool valve has a closed position intermediate the first position and the second position which restricts fluid flow between the source of load pressure and both the source of supply pressure and the pressure vent. The spool valve is moveably connected to the body.

Abstract: A brake control system determines utilizes a sensed amount of brake travel and a sensed amount of master cylinder pressure in determining a base brake control signal for an electro-hydraulic brake management system. The system also provides a springer function to provide an appropriate amount of brake jump-in, based on vehicle velocity and pedal travel. For pure brake-by-wire systems that have no hydraulic components, brake force is substituted for master cylinder pressure in determining a base brake control signal.

Abstract: An electronic brake management system for controlling the application of fluid pressure to the brakes associated with wheels on a vehicle is disclosed. The system comprises a plurality of hydraulic valves for controlling the application of fluid to the brakes and a plurality of valve drivers for controlling the valves in accordance with respective electrical control signals for the plurality of valves. The system further includes a valve pulse width modulation controller for generating the respective electrical valve control signals applied to the valve drivers. The electrical valve control signals from the pulse width modulation controller are modulated to reduce the amount of electrical power supplied by the individual ones of the electrical signals once the valve associated with the one of the electrical signals has changed its opening to a desired position.

Abstract: A brake control system determines when a wheel is unstable or stable during a braking condition. An unstable wheel is determined when the wheel speed is different from the estimated vehicle speed by greater than a fixed amount. When the wheel is determined to be unstable, an amount of brake pressure reduction is determined according to a proportional-plus-integral compensation. The proportional-plus-integral compensation is a function of the difference between the wheel speed and the estimated vehicle speed, as well as a wheel deceleration value. When the wheel is determined to be stable, brake pressure is applied according to an exponential rate. A hold mode is entered when the wheel is determined to be no longer decelerating during a dump cycle.

Abstract: An improved electro-hydraulic brake system having features for improving the pedal feel of the system, while further having design features which contribute to the economy of manufacture of certain components of the system. The system provides for an electrically powered normal source of pressurized hydraulic brake fluid, and a manually powered backup source of pressurized hydraulic brake fluid to the vehicle brakes in the event of failure of the normal source. During normal braking, fluid from the backup source is redirected from the vehicle brakes to a pedal simulator. The pedal simulator preferably includes arrangements of spring loaded pistons, expansion volumes, and damping orifices, together with valves selectively controlling the flow of fluid to and from the pedal simulator which provides for an improved pedal feel during vehicle braking.

Abstract: A dynamic rear proportioning system is integrated with an existing vehicle anti-lock braking system (ABS) and performs the function of the rear brake pressure proportioning where ABS is not required. The rear brake hydraulic channel(s) are isolated from the master cylinder by activating the rear isolation valves, provided in the ABS, to provide the optimum brake force balance, regardless of vehicle loading, without the use of a load sensing mechanism. The system estimates vehicle and wheel deceleration, vehicle speed, and lateral acceleration as well as the rear wheel slip to dynamically control the rear brake force. By continually updating these control parameters, the system can further increase or decrease the rear brake pressure to maintain the optimum brake force balance throughout the braking maneuver.

Abstract: A method and system for controlling an anti-lock brake system cycle rate in a vehicle wherein the cycle includes a primary apply stage and a secondary apply stage in which increasing pressure is applied to the brake. The primary and secondary stages are separated by a hold stage in which a substantially constant pressure is applied to the brake for a time interval which varies as a function of the estimated average vehicle deceleration.

Abstract: A method and system for modifying anti-lock brake control to a vehicle braking on a split mu surface. Each of the wheel speeds are sensed and compared to a wheel speed reference. If the speed of only one of the front wheels departs from the wheel speed reference in excess of a predetermined slip threshold, a split mu control is activated. Upon detecting a departure of the high mu wheel, a first pressure control profile is applied to the low mu wheel, while a second control pressure profile different from the first pressure control profile is applied to the high mu wheel. Once the vehicle has transitioned from braking on a split mu surface to braking on a homogeneous mu surface, normal ABS control pressure is applied to the wheels.

Abstract: The method and system for controllably restricting the on time of a pump of an electro-hydraulic control system for a hydraulic brake system by modeling the amount of hydraulic brake fluid in a low pressure accumulator (LPA) of the hydraulic brake system. Sensors sense wheel speed of their respective wheels of a vehicle. Control valves, including isolation and dump valves, together with the pump, vary the amount of brake fluid in the LPA. A control unit electrically coupled to the pump, the control valves and the wheel speed sensors, initially detects an electro-hydraulic control event based on the sensed wheel speeds and then activates the control valves and pump which vary the amount of brake fluid in the LPA. The control unit models the amount of brake fluid in the LPA during the activation and controls the state of the pump based on the modeled amount of brake fluid in the LPA.

Abstract: A method and system for modifying anti-lock brake control to a vehicle experiencing drivetrain-induced oscillations. A wheel speed of each of the wheels is sensed to generate a corresponding speed signal. A drivetrain-induced oscillation condition is detected in one of two ways. First, a wheel speed peak count is determined for each of the wheels. A drivetrain-induced oscillation is then detected if multiple peaks occur within a predetermined period of time. Alternatively, a frequency of oscillation for each of the wheel speeds is determined and compared to a predetermined frequency threshold. Upon determining that the vehicle is experiencing drivetrain-induced oscillation during an ABS event, brake pressure is applied to the driven wheels at approximately the same frequency as the frequency of oscillation of the drivetrain-induced oscillation.

Abstract: An improved electro-hydraulic brake system having features for improving the pedal feel of the system, while further having design features which contribute to the economy of manufacture of certain components of the system. The system provides for an electrically powered normal source of pressurized hydraulic brake fluid, and a manually powered backup source of pressurized hydraulic brake fluid to the vehicle brakes in the event of failure of the normal source. During normal braking, fluid from the backup source is redirected from the vehicle brakes to a pedal simulator. The pedal simulator preferably includes arrangements of spring loaded pistons, expansion volumes, and damping orifices, together with valves selectively controlling the flow of fluid to and from the pedal simulator which provides for an improved pedal feel during vehicle braking.