101 results about "Steering ratio" patented technology

A steering control apparatus for a vehicle including a steering input unit movable to set a steering input, and a steering output unit arranged to output a steering output, the steering input unit being connected via a cable to a body of the vehicle, includes a steering ratio control unit, a steering limiter, and a cable-attachment diagnostic controller. The steering ratio control unit regulates a variable steering ratio as a rate of change in the steering output with respect to a change in the steering input. The steering limiter restricts movement of the steering input unit to limit the steering input. The cable-attachment diagnostic controller is activated in a cable-attachment diagnostic mode, to control the steering ratio in such a manner that the steering input unit is movable over an allowable region defined by the steering limiter when the cable is correctly attached.

An object of the present invention is to reduce the possibility of a power assistance failure because of the phenomenon that steering assisting power which an electric power steering unit can generate is lower than the steering assisting power which is required for the electric power steering unit. A vehicle steering control device comprises an electric power steering unit, a steering ratio varying unit which drives an output member relative to an input member driven by steering operation of a driver to vary a steering ratio, and a control means which controls the steering ratio varying unit. The control means decreases in magnitude the relative drive velocity of the output member driven by the steering ratio varying unit relative to the input member when the magnitude of a difference between the maximum value of the steering drive velocity range of said steerable wheels which allows said power steering unit to generate a required steering assisting power and an actual steering drive velocity of said steerable wheels is small in contrast to the large difference.

The invention belongs to self-steering systems for automatic navigation of agricultural machines and particularly relates to a self-steering proportional control valve block and a navigation hydraulic system based on the self-steering proportional control valve block. The valve block is provided with a first pressure oil feed inlet, a second pressure oil feed inlet, an oil return port, a first steering hydraulic cylinder connector, a second steering hydraulic cylinder connector, a first load pressure feedback port and a second load pressure feedback port and comprises a load sensing oil port and a three-position and five-way proportional directional valve, a fixed-differential reducing valve, a one-way valve and a differential pressure type overflow valve, wherein the median function of the three-position and five-way proportional directional valve is in the Y type. An automatic navigation system can be formed by connecting the valve block with a core-opening full-hydraulic steering gear or a core-closing full-hydraulic steering gear or a load sensing type core-closing full-hydraulic steering gear. When the navigation system works, the quantity of oil flowing into the steering hydraulic cylinder is only related to the opening degree of the three-position and five-way proportional directional valve and is basically not affected by the change of the load of the steering hydraulic cylinder. According to the self-steering proportional control valve block, heat loss is small, the control accuracy is high, and the response speed is high.

A method for calculating the steering ratio at road cross based on genetic algorithm and maximum entropy model includes inputting flow rate data in certain time slot at study road cross and adjacent road cross, setting operator and control parameter of said algorithm and defining its search space and total frequency of solving solution, initializing calculation environment of said algorithm, executing genetic algorithm, calculating entropy of obtained solution and judging whether said total frequency is up or not if precision of obtained solution is satisfied and using solution corresponding maximum entropy as final solution if it is.

A dolly for the transport of elongated loads which includes an adjustable steer linkage assembly, an adjustable steer ratio, means for switching between rear- and forward-steering, and manual over-ride of the self-steering configuration. All of these adjustments can be achieved without the need to manually delink subassemblies.

A vehicle for line marking, having a steering mechanism (10) including: a directional wheel (5) that pivots about a steering shaft (12) coupled to a steering actuator (13); a control actuator (21) responsive to a steering wheel (22); and a universal joint coupling the control actuator (21) and the steering actuator (13) at a fixed angle between 20° to 70°, preferably 30° to 60°; the angle of the universal joint acting to produce a varying steering ratio as the steering wheel is moved away from its centred position. The vehicle includes a hydraulic pump circuit for a motor (101) driven line marking spray device (77) having a hydraulic supply line (105) for the motor with a check valve (107) and a high pressure accumulator (109) between the check valve and the motor and a pressure actuated ram (102) to deactivate the pump (100) when the pressure exceeds a threshold; the motor return line having a low pressure accumulator (110) and a restricted (112) bypass line (111).

A personal watercraft can have a steering nozzle pivoting in accordance with the operation of a steering handle unit to change the traveling direction of a vehicle body. A steering position sensor can be configured to detect the steering angle of the steering handle unit. An actuator can be arranged to pivot the steering nozzle to change the steered angle thereof. A running speed sensor can be configured to detect the running speed of the vehicle body, and a control device. The control device can determine an operational amount of the actuator and control the actuator based upon the detection amount of the steering position sensor, the running speed sensor, and a steering ratio preset with reference to the steering angle and the running speed. The steering ratio is set to be smaller as the running speed becomes larger.

A steering arrangement including a first, second, third and fourth hydraulic chamber, the first and third chambers being operable to steer in a first direction and the second and fourth chambers being operable to steer in a second direction. A pump system supplies fluid to a steering system, which is operable to supply the pressurised fluid to one or more of the first, second, third and fourth hydraulic chambers. The steering system having a first mode wherein fluid is supplied to the first and third hydraulic chambers to steer in the first direction, or pressurised fluid is supplied to the second and fourth hydraulic chambers to steer in the second direction. The steering system having a second mode to steer in the first direction, or to steer in the second direction, such that the steering ratio is higher in the second mode than in the first mode.

The invention relates to a vehicle steering control method and system. An angle sensor is arranged on a steering wheel and used for detecting the rotating angle of the steering wheel. A control unit calculates the wheel target steering angle according to the signal of the angle sensor. According to the differential value between the wheel target steering angle and the wheel actual steering angle,the control unit outputs corresponding steering proportional direction valve control current, and a steering proportional direction valve controls steering of a vehicle through a steering oil cylinder. The system is convenient to install, steering control is convenient and reliable, and the cost can be reduced effectively.

According to an active front steering system (AFS) of the invention, an actuator assembly that receives steering input from a driver and AFS input from a motor is mounted to a gear box that reciprocates a rack bar connected to tie rods that are connected to wheels. Therefore, the entire size of the AFS is reduced and a decelerator that changes the steering ratio includes a single planetary gear that outputs final steering through rack bar after the steering input from the driver and the AFS input from motor are inputted across each other.