Self-propelled vehicles that include swiveling caster wheels and independent drive wheels are disclosed. The self-propelled vehicles are selectively steered in a caster wheel steering mode or a drive wheel steering mode. The vehicle includes a steering position sensor to measure the position of the steering system. A control unit varies the rotational speed of first and second drive wheels based at least in part of the signal from the steering position sensor.

A power steering electrohydraulic system is provided for an electric vehicle, including: at least one reservoir of hydraulic fluid; and at least one hydraulic actuator for actuating a steering rack shaft of the vehicle; at least two electric motor pump units in parallel for supplying the actuator with hydraulic fluid from the reservoir and adjusting the flow rate of the hydraulic fluid supplied to the actuator, and each electric motor pump unit is a motor pump unit operating at a voltage of 24V. A vehicle equipped with such a system is also provided.

A power steering electrohydraulic system is provided for an electric vehicle, including: at least one reservoir of hydraulic fluid; and at least one hydraulic actuator for actuating a steering rack shaft of the vehicle; at least two electric motor pump units in parallel for supplying the actuator with hydraulic fluid from the reservoir and adjusting the flow rate of the hydraulic fluid supplied to the actuator, and each electric motor pump unit is a motor pump unit operating at a voltage of 24V. A vehicle equipped with such a system is also provided.

Parallel parking systems, vehicles equipped therewith, and methods of parallel parking a vehicle. Such a vehicle includes front and rear ends disposed on opposite ends of a longitudinal axis of the vehicle. At least one front wheel is disposed near the front end of the vehicle, at least one rear wheel is disposed near the rear end of the vehicle, a first steering mechanism is operatively coupled to the front wheel to change a turn angle of the front wheel, and a second steering mechanism operatively is coupled to the rear wheel to change a turn angle of the rear wheel independently of the front wheel.

Parallel parking systems, vehicles equipped therewith, and methods of parallel parking a vehicle. Such a vehicle includes front and rear ends disposed on opposite ends of a longitudinal axis of the vehicle. At least one front wheel is disposed near the front end of the vehicle, at least one rear wheel is disposed near the rear end of the vehicle, a first steering mechanism is operatively coupled to the front wheel to change a turn angle of the front wheel, and a second steering mechanism operatively is coupled to the rear wheel to change a turn angle of the rear wheel independently of the front wheel.

Provided is a power steering device capable of causing control that uses a pump device and control that uses an electric motor on an input shaft to cooperate with each other. The power steering device includes a power cylinder including a pair of hydraulic chambers partitioned by a piston and configured to generate a steering assist force for a steered wheel, a pump device configured to be driven through control by a first electric motor and configured to discharge working fluid, a rotary valve configured to selectively supply the working fluid supplied from the pump device to the pair of hydraulic chambers in accordance with relative rotation between the input shaft and the output shaft, a second electric motor provided so as to surround at least a part in an axial direction of the input shaft and configured to control the rotation of the input shaft, and a second electric motor control part installed in a control device and configured to output a control signal for controlling driving of the second electric motor based on a revolution number signal of the first electric motor.

Provided is a power steering device capable of causing control that uses a pump device and control that uses an electric motor on an input shaft to cooperate with each other. The power steering device includes a power cylinder including a pair of hydraulic chambers partitioned by a piston and configured to generate a steering assist force for a steered wheel, a pump device configured to be driven through control by a first electric motor and configured to discharge working fluid, a rotary valve configured to selectively supply the working fluid supplied from the pump device to the pair of hydraulic chambers in accordance with relative rotation between the input shaft and the output shaft, a second electric motor provided so as to surround at least a part in an axial direction of the input shaft and configured to control the rotation of the input shaft, and a second electric motor control part installed in a control device and configured to output a control signal for controlling driving of the second electric motor based on a revolution number signal of the first electric motor.

Systems and methods for curb detection for parking are disclosed. An example vehicle parking assist system includes a processor and memory. An example program stored in the memory is configured to move a vehicle using a set of maneuvers to park the vehicle in a parking space based on an estimated location of a curb. The example program is also configured to compare a first yaw rate to a reference yaw rate to detect when the vehicle contacts the curb. Additionally, the example program is configured to move the vehicle using an adjusted set of maneuvers based on an actual location of the curb.

The present invention provides a power assist steering system for a vehicle having a wheel. The steering system includes a first reciprocating member coupled to the wheel such that reciprocating movement of the first reciprocating member provides turning movement of the wheel, a steering input engaged with the first reciprocating member such that rotation of the steering input provides reciprocating movement of the first reciprocating member, and a steering assist assembly including a second reciprocating member engaged with the steering input such that reciprocating movement of the second reciprocating member provides an assist force to the steering input. Preferably, the first and second reciprocating members engage the steering input at locations opposed to each other and also move along paths that are substantially parallel to each other.

A steering rack piston assembly (10) employed in a power steering rack and piston assembly. The assembly includes a shaft (bar) (11) upon which there is mounted a piston (12). The shaft (11) has a longitudinal axis (13), that is also the longitudinal axis of the piston (12). The piston (12) has an outer groove (15) that receives a seal (16) that slidably engages in a cylindrical surface of an outer housing that is not illustrated. The piston (12) and shaft (11) move along the axis (13) relative to the outer housing as a result of pressure within the fluid located on opposite sides of the piston (12).