Hydraulic hybrid vehicle method of safe operation
AssigneeThe United States of America as represented by the Administrator of the U.S. Environmental Protection Agency
InventorCharles L. Gray, Jr.
Life of this patent
Estimating the term…
Abstract
A hydraulic hybrid vehicle includes elements such as a hydraulic pump driven by an internal combustion engine and arranged to draw in low pressure fluid and pump the fluid at high pressure to an accumulator. A hydraulic motor is powered by the pressurized fluid. Safety processes are provided for detecting and addressing a number of conditions that may arise in the operation of the hydraulic hybrid vehicle, including an initialization procedure for start-up of the vehicle, a shut-down procedure, and procedures for detecting and responding to failure of the pump or motor, internal and external fluid leaks, and non-responsive actuation and mode control systems.
Claims24
A process for initializing a hydraulic hybrid vehicle system, comprising:
- signaling initialization of the system;
- checking a position of a mode valve of the system;
- checking a displacement setting of a hydraulic motor of the system;
- coupling a high-pressure fluid supply to the system only if the mode valve is at a neutral position or if the displacement setting is at zero;
- and
- enabling operation of the vehicle only if, after performing the coupling step, the mode valve is at the neutral position and the displacement setting is at zero.
A process for initializing a hydraulic hybrid vehicle system, comprising:
- signaling initialization of the system;
- checking a position of a mode valve of the system;
- checking a displacement setting of a hydraulic motor of the system;
- coupling a high-pressure fluid supply to the system if either the mode valve is at a neutral position or the displacement setting is at zero;
- commanding the displacement setting to zero if, after performing the coupling step, the displacement setting is not at zero;
- rechecking the displacement setting of the hydraulic motor after performing the commanding step;
- decoupling the high-pressure fluid from the system if, after performing the coupling step and the rechecking step, the displacement setting is not at zero;
- and
- enabling operation of the vehicle if, after performing the coupling step and the rechecking step, the mode valve is at the neutral position and the displacement setting is at zero.
A process for initializing a hydraulic hybrid vehicle system, comprising:
- signaling initialization of the system;
- checking a position of a mode valve of the system;
- checking a displacement setting of a hydraulic motor of the system;
- coupling a high-pressure fluid supply to the system if either the mode valve is at a neutral position or the displacement setting is at zero;
- enabling operation of the vehicle if, after performing the coupling step, the mode valve is at the neutral position and the displacement setting is at zero
- checking a position of a shift selector after the signaling step and before performing the coupling step;
- and
- canceling the enabling step if the shift selector is not in either a park or a neutral position.
Dependencies are inferred from the claim text.