Daimler Chrysler Ag

Mercedes-benz Aktiengesellschaft

Other

Daimler-benz Ag

Daimchrysler Ag

Hubert Bohner

Martin Moser

Reinhold Schneckenburger

Mathias Hartl

Wolfgang Schrock

Gerhard Kurz

Rainer Freitag

Tobias Speidel

Wolfgang Schuliers

Karl-Eugen Laubacher

Bernd Schiek

Martin Rothmund

Hendrik Loos

Karsten Gerdes

Vehicle steering system

A vehicle steering system has a steering grip, in particular a steering wheel, which is operated by the driver, an actuating unit which operates steered vehicle wheels, and a manual force regulator which is coupled via a flexible coupling element with the steering grip and simulates parameter-dependent steering forces on the steering grip. A damping device is provided for reducing the formation of vibrations between the steering grip and the manual force regulator. The damping device interacts with the steering grip either directly or indirectly to damp relative motions between the steering grip and the manual force regulator.

A steering system functions in accordance with the &ldquo;steer by wire&rdquo; 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.

Steering system for motor vehicles

A steering system for motor vehicles, in which a steering member or steering wheel and the steered vehicle wheels are hydraulically positively coupled for the steering actuation of the wheels. An additional servo system is provided which is responsive to torque transmitted between the steering wheel and master unit of the hydraulic system.

Motor vehicle steering system

A steering system is provided for motor vehicles, in which, during the normal operation, the driver adjusts an actual steering angle value generator by way of a steering handle. A control and automatic control arrangement correspondingly operates the steered vehicle wheels by a motor-operated adjusting assembly. For an emergency, a forced coupling is provided between the steering handle and the steered vehicle wheels which switches on automatically. This forced coupling is constructed such that a centering mode can be switched on, during which, when the forced coupling is at least partially switched off, the manual steering wheel can be adjusted until a position is reached. Thereby, in the straight-ahead position of the steered vehicle wheels, the manual steering wheel takes up a defined normal position.

A steering system for motor vehicles, has a steering handle, for example steering handwheel, capable of being operated by the driver. A steering actuating drive provides for the steering adjustment of steerable vehicle wheels. A steering-angle desired-value encoder is capable of being operated by the steering handle, and a steering-angle actual-value encoder operates via the steerable vehicle wheels. A regulating and control arrangement operates the steering actuating drive as a function of a comparison of the desired and actual values of the steering angle. The risk of a collision between a vehicle equipped with the steering system and an obstacle is reduced, and the steering system is suitable for steer-by-wire operation by equipping the steering system with collision prevention apparatus which determine steering angles (collision steering angles) making a collision possible between the motor vehicle and an obstacle. The regulating and control arrangement hinders or prevents the setting of a desired steering angle coinciding with one of the collision angles.

A steering valve arrangement of a hydraulic steering system has a rotary valve with a first and a second control part that are rotationally movable relative to one another. By rotational adjustment of the control parts a hydraulic servomotor is controlled which is connected drivewise with the steered wheels of a vehicle. An electric motor is mounted in a fixed location for actuating the rotary valve relative to the first control part and is connected drivewise with the second control part. The driving connection from the electric motor to the second control part is provided indirectly by a step-down transmission, including a small gear fixed to the motor drive shaft and a large gear connection with the second control part. The steering valve and the motor are disposed side by side and parallel to one another in a compact design.

Steering valve arrangement of a hydraulic steering system

A hydraulic power steering system for motor vehicles which is suitable for a steer-by-wire operation, having a steering handle which can be operated by a driver. A servo motor operates steered vehicle wheels. A servo valve operates the servo motor and is constructed as a rotary slide valve arrangement having mutually rotationally movable control parts which, together, are pushed by a spring system into a normal position relative to one another. An actuator is coupled with the control parts for their rotational adjustment relative to one another and operates the servo valve. A desired steering angle value generator is operated by way of the manual steering handle. An actual steering angle value generator is operated by way of the steered vehicle wheels. An automatic control circuit operates the actuator as a function of a comparison of the desired and actual steering angles. In order to improve this power steering system with respect to its control performance, an angle sensor is coupled with the control parts which detects their relative angular position. The automatic control circuit takes into account this relative angular position when operating the actuator.

Power steering system for motor vehicles

A way is provided to simulate the steering handle manual torques which correspond to a steering stop of the steered vehicle wheels for a vehicle steering system which can be operated in a normal mode and in an emergency mode. The steering system is capable of being switched between a steer-by-wire level assigned to the normal mode, on which level a steering handle is connected to steered vehicle wheels via an electric or electronic control system, and a fall-back level assigned to the emergency mode, on which level the steering handle is positively coupled mechanically and/or hydraulically to the steered vehicle wheels. The fall-back level is activated in normal mode if the steered vehicle wheels are displaced into the region of the steering stop.

Method for operating a vehicle steering system

A steering system for vehicles can be operated in a normal mode, in which a steering handle actuated by the driver and steered vehicle wheels are connected to one another via a control system, and in an emergency mode, in which the steering handle and the steered vehicle wheels are positively coupled. To achieve a steering system which increases the operational reliability of the steering system by simple design measures, a steering-angle control unit for a steering-angle actuator actuates the steered vehicle wheels. The control unit contains a first steering-angle control system, and a manual-torque control unit for a manual-torque actuator actuates the steering handle for the purpose of simulating manual torques. The control unit also contains a first manual-torque control system, and the steering-angle control unit comprises a second manual-torque control system, which is connected redundantly with the first manual-torque control system of the manual-torque control unit. The manual-torque control unit comprises a second steering-angle control system which is connected redundantly with the first steering-angle control system of the steering-angle control unit.

Steering system for a vehicle

In order to allow a traffic-lane following device in a vehicle to be used at relatively high vehicle speeds, a steering system is provided with a steering handle and a steering run which couples the steering handle to vehicle steered wheels. A servomotor is coupled to the steering run. A servovalve is arranged in the steering run and has a first control part (which is associated with a section on the steering handle side of the steering run) as well as a second control part (which is associated with a section on the vehicle steered wheel side of the steering run) to operate the servomotor as a function of relative movements between the control parts. An actuating drive is coupled to the section on the steering handle side of the steering run and is used to produce a steering force. A regulating and control arrangement uses a sensor system to determine required steering angle values which allow a traffic lane to be followed and uses a steering angle sensor to determine actual steering angle values. The actuating drive is operated as a function of a comparison of the required and actual steering angles, in which the steering angle sensor interacts with the section on the vehicle steered wheel side of the steering run.

Steering system for a vehicle equipped with a traffic-lane following device

A steering system of a non-tracked motor vehicle has steered vehicle wheels are connected in 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, 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. This also takes place if the performance limit of the adjusting drive is reached so that the driver is capable of assisting the adjusting drive by the driver's manual force on the steering handle.

Steering system for non-tracked motor vehicles

A steering system has a steering wheel and steered vehicle wheels which are normally connected only controlwise by a control system, with the steering wheel actuating a steering angle setpoint generator and with the steered vehicle wheels adjusting a steering angle actual value generator so that the control system can actuate a motorized steering control assembly in accordance with a setpoint-actual value comparison of the steering angle during control of the steered vehicle wheels by steering. Axial displaceability of the steering wheel is provided so that stable mounting prevents vibrations of the steering wheel and the feedback effects on the steering angle setpoint generator originating therefrom.

Steering system

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.

A steering system of a non-track-bound motor vehicle having steered vehicle wheels which are operatively connected to a steering handle in normal operation only via an electronic regulating arrangement which checks itself continuously for correct operation. In a manner dependent on a desired-value transmitter actuated by the steering handle and on an actual-value transmitter actuated by way of the vehicle wheels, this regulating arrangement actuates an actuating drive for the steering displacement of the steered vehicle wheels. If the regulating arrangement malfunctions, a positive coupling between the steering handle and the steered vehicle wheels is automatically activated. This also occurs if a characteristic variable correlated with the desired/actual value deviation of the steering angle is outside tolerance thresholds.

Growing community of inventors

Boeblingen, Germany

Hubert Bohner