DE102009015365A1 - Electrical servo steering device for steering motor vehicle, has electric motor for generating support steering moment and detection unit for detecting energy requirement of electric motor - Google Patents

Abstract

The electrical servo steering device has an electric motor for generating a support steering moment. A detection unit is provided, which detects an energy requirement of the electric motor during the generation of the support guidance moment. A regulating unit is provided at a steering wheel.

Description

The The present invention relates to an electrically assisted Power steering device for steering a motor vehicle according to the Preamble of claim 1.

From the DE 198 22 170 A1 is a generic electrically assisted power steering device for generating a steering assistance in response to a steering control signal known. This has a steering torque sensor which is operatively connected to a vehicle steering wheel for generating a torque signal corresponding to an applied steering torque. An electric motor control module is connected to the torque sensor and to an electric motor and at the same time has an outer loop control device for generating a desired torque signal responsive to the applied steering torque. The controller in turn has a phase delay network connected in series with a second order network for balancing the desired torque signal. Further, the electric motor control module includes an inner loop controller for generating a motor drive signal, the inner loop applying the motor drive signal to the electric motor to produce a desired assist torque. With this power steering device, a steering system is to be created, which has stability, low vibration and low fuel consumption.

From the DE 10 2004 047 545 A1 a device for generating a haptic driver feedback is known, with driving condition detecting means which detect the actual driving state of the vehicle, which is then evaluated in an evaluation unit. A feedback device is controlled by the evaluation unit as a function of the evaluation result and produces an excitation variable generating the haptic driver feedback with a sinusoidal time profile.

Finally, out of the DE 10 2005 008 875 A1 a method for assisting a vehicle driver in the control of a target position known. Here, the driver is given a haptic feedback whether he moves along a previously determined target trajectory to achieve the target position of the current vehicle position, being signaled via variable auxiliary forces on the steering wheel, whether the vehicle moves along the desired trajectory in which the For applying the steering wheel of the driver to be applied forces is increasingly greater, the further the vehicle moves away from the target trajectory and opposite.

Especially in so-called "steer-by-wire" steering, which no direct steering connection between a steering handle and the steered vehicle wheels, is the driver over a corresponding adjusting device a counter-steering torque on the steering handle applied, but which is usually constant to at least to simulate a certain steering resistance. adversely However, this is that the constant applied to the steering handle Countersteering moment no real relation to the actual driving or steering situation possesses.

The The present invention therefore deals with the problem of for an electrically assisted power steering of the generic type, an improved or to provide at least one alternative embodiment, the is characterized in particular by a real steering behavior.

This Problem is inventively by the subject of the independent claim 1 solved. advantageous Embodiments are the subject of the dependent Claim.

The The present invention is based on the general idea, on a Steering handle in a motor vehicle a realistic To generate counter-steering torque, which at least to an actual Steering resistance is approximated. This is used in electrically assisted power steering with an electric motor for generating an assist steering torque. The electric motor is according to the invention associated with a detection device, which detects an energy requirement of the electric motor when generating the Stützlenkmoments. At the steering handle of the power steering device is an adjusting device provided, which is a haptic recognizable by a driver countersteering torque generated on the steering handle, and in response to the Energy consumption of the electric motor when generating the Stützlenkmoments.

hereby In particular, a steering against an obstacle, for example. Against one Curb, haptic directly reported to the driver. Likewise a stiction of the road is communicated to the driver so that this haptically acceptable to the driverally acceptable border area can feel. Reduced with increasingly smoother road surface this is the applied by the electric motor Stützungslenkmoment and thereby its power consumption, which in turn also from the Setting device on the steering handle generated Gegenlenkmoment reduced will, so the driver due to the decreasing steering resistance can recognize on the steering handle, as the roadway is designed and in particular from when to fear the loss of traction is.

at an advantageous embodiment of the invention Solution, is a size of the actuator on the steering handle generated Gegenlenkmoments proportional to recorded energy consumption of the electric motor. Proportionality between energy consumption of the electric motor and generated counter-steering torque on the steering handle improves the haptic perception of each Steering situation by the driver considerably, which makes driving in particular with steer-by-wire steering becomes safer.

A electrical superposition steering, in particular an electrical superposition steering with Emergency steering function, which is preferably used in four-axle vehicles finds contrary to the steer-by-wire steering a direct steering connection - a mechanical penetration - between the steering handle and the steered vehicle wheels on. Thus, especially in a superposition steering with emergency steering function a reduction of the engine torque of the electric motor is sufficient, in order to achieve an increased steering force, the proportionality between energy consumption of the electric motor and generated counter-steering torque at the steering handle by a haptic feedback one clear distinction between comfort steering and emergency steering allows.

As a general rule has the power steering device according to the invention the great advantage that the generated at the steering handle Gegenlenkmoment in a real relation to the actual Steering situation, for example, to steer against an obstacle, stands. By the immediate haptic feedback by the at the steering handle generated counter-steering torque can the driver a particularly realistic Steering behavior can be simulated, resulting in increased driving safety contributes.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19822170 A1 [0002]
• - DE 102004047545 A1 [0003]
• DE 102005008875 A1 [0004]

Claims (2)

Electrically assisted power steering device for steering a motor vehicle with an electric motor for generating a Stützungslenkmomentes characterized in that - a detection device is provided which detects an energy demand of the electric motor when generating the Stützlenkdreomentes, - is provided on a steering handle an adjusting device on the steering handle a Gegenlenkmoment or generates an at least reduced torque depending on the power consumption of the electric motor. Power steering device according to claim 1, characterized that is a size of the actuator the steering handle generated Gegenlenkmoments proportional to the detected Energy consumption of the electric motor is.