Abstract: A vehicle steering apparatus includes a steering input section having at least a steering wheel to which steering input is applied, and a steering output section having at least a steering rack shaft and operatively associated with left and right steered wheels for steering the steered wheels by steering-rack-shaft movement produced by a steering force determined based on the steering input and transmitted directly or indirectly to the steering rack shaft. The steering rack shaft is split into left and right movable rack shaft portions. Also provided is a steer angle converter enabling a differential rack stroke between left and right rack strokes of the left and right movable rack shaft portions. The steer angle converter is constructed by at least one of a variable-pitch dual rack arrangement and a dual taper-pulley arrangement of a cable back-up mechanism.

Abstract: In a power steering system employing a power cylinder for steering assistance, hydraulic pressure is supplied through a pair of fluid lines to respective hydraulic chambers of the power cylinder. Check valves are provided to charge a hydraulic pressure in a communicating circuit intercommunicating the two fluid lines. Also provided is a solenoid-actuated directional control valve for relieving the hydraulic pressure charged in presence of a power steering system failure. An opening of the directional control valve varies depending on a solenoid attracting force and a pressure differential between the hydraulic pressure in the communicating circuit and hydraulic pressure in a reservoir. A relatively low exciting current is applied to the solenoid when the hydraulic pressure charged exceeds a predetermined pressure value. A relatively high exciting current is applied to the solenoid when the hydraulic pressure charged is less than or equal to the predetermined pressure value.

Abstract: Device for manoeuvring a tension wheel in a chassis of a tracked vehicle, in which the tension wheel is rotatably mounted on a telescopic rocker arm (12). The rocker arm can, on the one hand, be lengthened and shortened by a first hydraulic cylinder and, on the other hand, swivelled about a transverse axis (14) by a second hydraulic cylinder for the purpose of raising and lowering the tension wheel. The first hydraulic cylinder is designed to act upon a lever arm (58) of a sleeve (54) rotatable in a hub part (20) of an inner part (18) of the rocker arm (12), which sleeve has an eccentrically mounted crank pin (52) which is hinge-connected to an outer part (22) of the rocker arm for the purpose of displacing the latter relative to the inner arm part, in the event of a mutual rotation motion between the sleeve (54) and the hub part (20) of the inner rocker arm part, in such a way that the rocker arm is lengthened upon a downward swivel motion of the arm and the tension wheel.

Abstract: A manual control device for electrically driven and controlled steering, and/or accelerating and/or decelerating of a road vehicle, that includes a hand grip device, sensors for sensing a force and/or a movement imposed on the hand grip device which correspond to a desired steering direction, and/or acceleration and/or deceleration of the vehicle, as well as a manual lever device comprising at least one mechanical connection for mechanically steering, and/or accelerating, and/or decelerating (e.g. maintenance parking etc.) of the vehicle in the absence of electric power (e.g. in the case of an electric power failure or in the case of electric power switched off) maintenance, garage parking etc., the manual lever device being swivelable or rotatable about at least one axis for actuating said at least one mechanical connection.

Abstract: A vehicle steering system is provided with a primary steering system, a backup steering system and a control system that switches from the primary steering system to the backup steering system when a defect is determined in the primary steering system such as a defeat in a steering reaction force actuator. The vehicle steering system has a pair of clutches that mechanically disconnect the steering wheel from the steerable vehicle wheels in normal situations, and connect them when the steering reaction force actuator is determined to be defective. The control system has a steering malfunction detection section that detects a malfunction in the steering reaction force actuator, and a steering control limiting section that limits the control commands to the steering gear unit actuator from when the steering reaction force actuator is determined to be malfunctioning to when both the clutches are connected.

Abstract: A power steering system includes a reversible pump for supplying hydraulic fluid to pressure chambers of a power cylinder through first and second passages, an assisting-force detector for detecting a steering assisting force to be provided to a steering wheel, a motor control circuit outputting a drive signal to an electric motor in accordance with the detected steering assisting force so as to obtain a desired hydraulic pressure, a communication passage for providing fluid communication between the first and second passages, a solenoid valve for switching between communication and interruption of the communication passage, and a current detector for detecting a current passing through an energization circuit of the solenoid valve and between the solenoid valve and a ground.

Abstract: A steering system, e.g., a hydraulic rack and pinion steering system for motor vehicles, includes a steering handle for prescribing a steering intention, a pressure medium source and a control valve device for controlling a flow of pressure medium to and from a servomotor in order to deflect vehicle wheels. The control valve device has a closed center, and a pressure medium accumulator is provided for producing and/or assisting a flow of pressure medium to and from the servomotor.

Abstract: In steering apparatus and method for an automotive vehicle, a turning section that turns steered road wheels is provided, a clutch is installed in a predetermined position in a midway through a steering system from an operation input section to the steered road wheels to link between the operation input section and the steered road wheels, a steering angle of the operation portion is detected, a turning angle is detected, an elastically deformable member is interposed between the operation portion and the turning portion to transmit a steering torque inputted from the operation input section to the steered road wheels when the clutch causes the operation input portion and the steered road wheels to be connected; and an angular deviation between the steering angle detection value and the turning angle detection value developed due to a deformation of the member is calculated.

Abstract: The present invention involves a system and method of re-configurable control for a vehicle steer-by-wire system. A steer-by-wire control system includes a steering wheel control system and a road wheel control system for a vehicle. Each control system is provided with a respective controlled plant and a re-configurable controller. The controllers receive output measurement signals from the respective controlled plants and produce control command signals for the controlled plants for re-configurable control of the steer-by-wire system. An adaptive re-configurable control is provided with fault detection and isolation, fault decision, parameter identification for the steer-by-wire controlled plant, and the re-configurable controllers with automatic adjustable structure and/or parameters. The re-configurable controllers automatically adjust their structure and parameters to maintain stability and certain performance requirements despite faults that occur in the steer-by-wire system.

Abstract: The vehicle steering system includes a steering operating device operable by the driver, in particular a hand steering wheel, each one electromechanical actuator for controlling of each steerable wheel of a wheel pair on a steerable vehicle axle at the right and left side of a vehicle body, means which, in the event of failure or a malfunction of one of the two actuators associated with a steerable vehicle axle, ensure the control of the two vehicle wheels of this vehicle axle by the respectively other, still functioning actuator, at least one set-value transducer for a steering angle being adjusted that is operable by the steering operating device, at least one actual-value transducer recording the steering angle of the vehicle wheels, a central control unit which controls the electromechanical actuators in dependence on a comparison of a signal of the actual-value transducer (actual value) with a signal of the set-value transducer (set value), and a data transmission unit which establishes a data communicat

Abstract: In a vehicle steering apparatus, a steering actuator is controlled so that the steering angle varies in accordance with the operation of an operating member. A transmission mechanism connects an operating side rotating member that is mechanically connected to the operating member and a vehicle wheel side rotating member that is mechanically connected to the vehicle wheels so that the mutual transmission of rotation is possible. Furthermore, the rotational transmission ratio between the operating side rotating member and the vehicle wheel side rotating member can be varied.

Abstract: A steering system functions in accordance with the “steer by wire” concept and has a normal operating system without positive coupling between the steering handle and the steered vehicle wheels, as well as an emergency operating system, which functions with positive coupling between the steered vehicle wheels and the steering handle. An auxiliary operating system is additionally provided, which, in response to malfunctions of the normal operating system, assumes its tasks and, in a transitional phase, adapts the performance characteristics of the steering system to those of the emergency system, which is switched on upon conclusion of the transitional phase. Thus, at the transition from the normal operating system to the emergency operating system, the driver is given time to become accustomed to the other steering performance.

Abstract: Provision of a fail-safe circuit which is capable of allowing a sub circuit to operate with reliability when a main circuit encounters abnormal conditions even in a system with only one supply source of pressure oil. A plurality of solenoid type control valves (3, 6) connected to an actuator (1) in parallel have centering springs respectively and are maintained at a neutral position in normal conditions. Each control valve is provided with a supply port, a return port and two actuator ports and is configured such that in the neutral position, the supply port and the return port are communicated with each other and interrupts communication with the actuator ports.

Abstract: The present invention comprises a steering system selectively operable in one of three modes: steer-by-wire, electronic power assist steering (EPAS), and manual steering. The steer-by-wire system includes a driver interface system (DIS), a road wheel actuator system (RWAS), and a controller for monitoring and implementing the preferred control strategy. The steering system of the present invention operates normally in a steer-by-wire mode. In each of the EPAS mode and manual mode, the controller causes a clutch mechanism to engage, thus creating a mechanical linkage between the steerable member and the rack and pinion system. In the EPAS mode, one of the road wheel actuator or the reaction torque generator is available to assist in the steering operation. Alternatively, in the manual mode, both the DIS and the RWAS are deactivated and the vehicle is steerable through entirely mechanical means.

Abstract: A power steering apparatus includes a motor, a torque sensor, and a motor resolver. The motor generates an assisting force to reduce the steering force of the steering wheel. The torque sensor detects the steering torque of the steering wheel. The motor resolver detects the rotational angle of the motor. An electronic control unit (ECU) detects the absolute position of the steering wheel based on a detection signal Rt sent from a second resolver of the torque sensor and a detection signal Rm sent from a motor resolver. As a result, the cost is reduced and the absolute position of the steering wheel is accurately detected.

Abstract: An apparatus and method for steering a vehicle (not shown) provides an input member or steering wheel for receiving steering inputs from a user; a steering-torque sensor mechanically coupled to the input member for sensing the torque applied to the steering wheel; a control circuit electronically coupled to the steering-torque sensor for producing a signal corresponding to the measured driver steering torque; an output actuator electronically coupled to the control circuit and road wheel for receiving the electronic signal and translating it into mechanical motion; and an output member or road wheel mechanically coupled to the output actuator for steering the vehicle (not shown).

Abstract: A steering system functions in accordance with the “steer by wire” concept and has a normal operating system without positive coupling between the steering handle and the steered vehicle wheels, as well as an emergency operating system, which functions with positive coupling between the steered vehicle wheels and the steering handle. An auxiliary operating system is additionally provided, which, in response to malfunctions of the normal operating system, assumes its tasks and, in a transitional phase, adapts the performance characteristics of the steering system to those of the emergency system, which is switched on upon conclusion of the transitional phase. Thus, at the transition from the normal operating system to the emergency operating system, the driver is given time to become accustomed to the other steering performance.

Abstract: An apparatus (10) for turning the steerable wheels (17) of a vehicle in response to the turning of the steering wheel (12). The apparatus (10) includes a drive mechanism (16), a first motor (24), a second motor (74), a sensor (78) for sensing that the first motor (24) is inoperative, and a torque sensor (80). In response to the turning of the steering wheel (12), the drive mechanism (16), is actuated, resulting in a turning the steerable wheels (17). The first motor (24), for inputting motion to the drive mechanism (16), is hydraulically powered. The second motor (74), for inputting motion to the drive mechanism (16), is electrically powered. The sensor (78) for sensing that the first motor (24) is inoperative produces an enabling signal and communicates the enabling signal to the second motor (74) to enable the operation of the second motor (74). The torque sensor (80) responds to the turning of the steering wheel (12) and controls the second motor (74) when the second motor (74) is enabled.

Abstract: A steering device for self-propelled working machines. Steering cylinders are associated with each pair of wheels and a fluid which is suppliable from a valve unit to the cylinders. At least one hydraulic pump is connected to the valve unit via hydraulic lines, and the valve unit includes a respective switching unit (16, 19) incorporating on-off valves (24, 25, 25′) associated with each steering cylinder (8, 9). In the event of a fault, the on-off valves (24, 25, 25′) are automatically switchable in a manner such that the steering cylinders (8, 9) can be controlled by a single steering control unit (18).

Abstract: An arrangement for steering a motor vehicle having at least two steerable wheels including steering equipment for setting the position of the steerable wheels as a function of a desired steering angle signal and braking equipment which is present in the vehicle and which, in the event of a fault in the steering equipment, produces selectively different braking forces at the wheels as a function of the desired steering signal. A method for steering a motor vehicle in the event of failure of the steering equipment includes the step of applying different braking forces to the vehicle wheels in accordance with a desired steering angle signal.

Abstract: High functional reliability for a vehicle steering system that can be switched between a normal mode with a steer-by-wire level and an emergency mode with a fall-back level is achieved by providing that the fall-back level has a hydraulic system which contains a manual-side double-acting piston-cylinder unit which is actuated with a steering handle, e.g. steering wheel. The unit is positively coupled hydraulically to a wheel-side double-acting piston-cylinder unit which actuates steered vehicle wheels. A hydraulic charging system has a hydraulic pump, the inlet side of which is connected to a hydraulic-fluid reservoir. Switchable hydraulic couplings are provided for hydraulically coupling and decoupling the hydraulic system of the fall-back level and the hydraulic charging system to and from one another, respectively.

Abstract: A steering system for a motor vehicle is not trackbound and has steered vehicle wheels which are connected only operationally in normal operation to a steering handwheel via an electronic control arrangement which actuates a steering actuator in accordance with a desired-value stipulation by way of the steering handwheel. In emergencies, a mechanical positive coupling becomes effective between the steering handwheel and the steered vehicle wheels. The operational state of the clutch is monitored by a sensor system in the case of normal operation, with the result that the normal operation can remain switched on only if the clutch is unambiguously open.

Abstract: A steering system of a non-tracked motor vehicle whose steered vehicle wheels are connected in the normal operation with respect to the effect with a steering handle only by way of an electronic automatic control unit which continuously monitors itself with respect to a correct operation. As a function of a desired-value generator, which is operated by the steering handle, and an actual-value generator operated by the vehicle wheels, this automatic control system operates an adjusting drive for the steering adjustment of the steered vehicle wheels. In the event of a malfunctioning of the automatic control system, a forced coupling is automatically switched effective between the steering handle and the steered vehicle wheels. When the forced coupling is switched on, the steering system operates as much as possible in the manner of a conventional power steering system.

Abstract: A motor driven system for steering a vehicle is provided, the system including a steering control device and a steering device connected through a motorized device, the motorized device transmitting movement to the steering device, the movement having an amplitude different from the movement given to the control device by the driver. The change in amplitude is controlled by a control unit according to various parameters. In this way, the degree of movement of the steering control device is changed by the motorized device such that operators having diminished physical capacity are able to operate the steering control.

Abstract: A vehicle steering system has a steering handle as well as steered vehicle wheels connected with one another with respect to the effect at least in the normal operation only by way of a control device ("steer by wire") which compares the signals of a steering angle actual value generator operated by the vehicle wheels and of a steering angle desired value generator operated by the handle. The control device controls a motor used as a manual force adjuster which is coupled with the handle by way of a torsionally elastic shaft arrangement. The extent of the torsionally elastic deformation is analyzed for determining the actual value of the manual force.

Abstract: A steering system for mobile machines includes at least two hydraulic pumps; at least one steering gear connected to the at least two hydraulic pumps by hydraulic lines, the hydraulic lines being brought together to form a single feed line that is connected to the steering gear; at least one steering cylinder connected to the steering gear; and a return element being provided in each of the hydraulic lines connecting the respective pumps and at least one steering gear; wherein the at least two hydraulic pumps are variable displacement pumps that have pressure and feed current regulators, the regulators being adjustable to predetermined, variable load-sensing differential pressures.

Abstract: In a hydraulic power steering for a motor vehicle including a steering control element, a position setting means connected to the steering control element to be operated thereby, a control motor connected to the position setting means by way of a control circuit and a servo valve having control parts interconnected by a torsion bar so as to be retained in a predetermined position relative to each other, a hydraulic servo motor is operatively connected to the steered wheels of the motor vehicle and in communication with the servo valve such that hydraulic fluid is supplied to the hydraulic servo motor depending on the relative position of the control parts of the servo valve.

Abstract: An emergency backup steering system for a wheeled vehicle controls steering of the vehicle upon failure of the primary vehicle steering system, by unequal braking of wheels on opposite sides of the vehicle.

Abstract: A device for the parameter-dependent control of a reaction force at an operating element, in particular a steering wheel of a motor vehicle, of a hydraulic power steering system. In this case, a parameter-dependent additional force is generated by an electric motor in addition to a hydraulically generated servo positioning force.

Abstract: In a hydraulic power steering for motor vehicles having a steering control element, a position setting unit connected to the steering control element, a control motor connected to the position setting unit by way of a control circuit and a servo valve having control parts which are supported so as to be rotatable relative to each other but operatively interconnected by spring means retaining them in a central open position relative to each other, one of the control parts is operatively connected to the control motor and the other is connected to a steering gear mechanism associated with the steered wheels of the motor vehicle, and a hydraulic servomotor is associated with the vehicle wheel steering mechanism and hydraulically connected to the servo valve to receive hydraulic fluid therefrom depending on the relative rotary positions of the servo valve control parts.

Abstract: A vehicular brake booster using fluid pressurized by a hydraulic power steering system hydraulic pump. Fluid pressure is controlled by using a pressure regulator in the pump output and by electronically switching fixed orifices in a boost developing valve controlling fluid flow within the power steering system. Additional control is effected by electronically opening and closing apply and relief valves controlling fluid flow respectively to and from a brake power booster for differing periods.

Abstract: A vehicle has a steering control system including a first mode in which the front and rear steering mechanisms operate and a second mode in which only the front steering mechanism operates. When the control system is switched from the first mode to the second mode by a master switch, the change to the second mode is prevented unless and until the rear steering mechanism is in a straight-ahead condition. This condition is sensed by an alignment sensor which is activated by the switching of the master switch to the state corresponding to the second mode.