WO2007017364A1

WO2007017364A1 - Method for automatically transferring a vehicle from a driving state into a stationary state

Info

Publication number: WO2007017364A1
Application number: PCT/EP2006/064528
Authority: WO
Inventors: Mark Baijens; Thomas Meurers
Original assignee: Continental Teves Ag & Co Ohg
Priority date: 2005-08-05
Filing date: 2006-07-21
Publication date: 2007-02-15
Also published as: DE102006034253A1

Abstract

In order to permit a stationary state of the vehicle in a predefined TARGET position of the vehicle when said vehicle is braked automatically, two activation conditions and a navigation system are provided which are used to determine the ACTUAL position of the vehicle and a TARGET position of the vehicle. According to the invention, a braking torque or a deceleration are determined as a function of the positions of the vehicle.

Description

Method for automatically transferring a vehicle from a driving state to a stationary state

The invention relates to a method for automatically transferring a vehicle from a driving state to a stationary state according to the preamble of claim 1.

The number of assistance functions in the vehicle is constantly increasing. For example, it is known from DE 3728709 to secure a vehicle from rolling away after completion of a braking operation leading to standstill in vehicles by automatic actuation of the service brake.

In addition, it is also known, for example, from DE 19838885 Al to keep a vehicle at a standstill by performing a possibly also automatic actuation of the parking brake. In addition, there is

Cruise control systems providing automatic intervention in engine management and braking when a preselected distance to a preceding vehicle is achieved. WO 02/06074 A1 describes a method and a device for controlling The speed of a vehicle that wants to reduce or limit the speed to very small values when driving downhill. For this purpose, it is provided that a low constant maximum speed can be specified.

EP 0679974 B1 describes an integrated

Vehicle positioning and navigation system for determining the terrestrial position of an autonomous vehicle at or near the surface of the earth.

A function under development is "Active Vehicle Stop" (AVS), which is intended to make braking easier for the driver, especially in automatic transmissions or automated manual gearboxes The driver can normally accelerate and brake, but as soon as the accelerator pedal is released, the car no longer rolls out, but is automatically released by the driver

Driving state transferred to the standstill state. The stopping is achieved by setting a braking torque or a delay. It is braked with fixed, predetermined values. After reaching the vehicle standstill, the vehicle is automatically held by the service brake of the traction help function.

By specifying a fixed amount for the deceleration or the braking torque, the stopping distance from the vehicle for the driver is not exactly predictable. The function It only guarantees that the vehicle will be brought to a standstill automatically and comfortably, leading to significant deviations in the daily use of this function.

The invention is therefore based on the object to change the stopping process of the car such that a defined vehicle target position is achieved when transferring to the standstill state.

Systems such as ACC Stop and Go can theoretically be brought to standstill behind stationary vehicles at a given distance, but require expensive additional environment detection systems. In contrast to the complex ACC systems, AVS controllers are cost-effective to implement at low speeds (city traffic). Both functions are activated via separate activation conditions but can share sensors.

The inventive solution to this problem is solved by the features of claim 1.

Advantageous developments are specified in the subclaims.

According to the invention, the vehicle is transferred from a driving state to an operating state of standstill by carrying out the following steps: a) activating the method after a first predetermined activation condition. Preferably, the first predetermined activation condition is a button which the driver must operate in order to activate the function.

Alternatively, as the first activation condition, the operation of a pedal at idle can be provided. b) activating the method according to a second predetermined activation condition. Preferably, the second activation condition is the release of the accelerator pedal. Only when the accelerator pedal is in its starting position, the vehicle is transferred to the standstill state. c) evaluating data of a navigation system with respect to a vehicle ACTUAL position and a vehicle TARGET position. Method and device for determining the position of a vehicle are known from DE 19915212 A1 or the already mentioned DE 69033964 T2. These methods and devices rely on navigation systems by means of which the vehicle's actual position can be determined. Based on the road maps stored in the navigation systems, vehicle target positions such as road intersections or the like can also be determined. Taking into account additional traffic information for the function of the vehicle-integrated route planning of the navigation system, which includes an internal digital road map, moreover makes it possible to recognize Vehicle congestion. Likewise, objects located on or on the road and provided with short range transmitters may be considered in evaluating the data of the navigation system. Such traffic sign detections as well as the traffic information of the broadcasters or the information of a vehicle-to-vehicle information allow a more accurate determination of the vehicle TARGET position. From the vehicle actual position and the vehicle target position, the distance to the vehicle target position can be calculated. Determining a braking torque or a delay as a function of a dependent on the vehicle positions size to reach the stationary state of the vehicle at the vehicle TARGET position. From the position of the vehicle and the distance to the vehicle TARGET position or the stopping point of the vehicle, the resulting deceleration or the required braking torque can be calculated. Vehicle-internal sensors or models can be used to determine additional driving condition information, which is taken into account when determining the braking torque or the deceleration. Depending on this driving state information, the deceleration or braking torque may be modified so that the vehicle can be safely transferred to the stationary state at the vehicle target position. An embodiment of the invention is illustrated in the drawing and will be described in more detail below.

1 shows an apparatus for carrying out the method according to the invention. A tax and

Evaluation unit 10 is connected to a first activation unit 11 and a second activation unit 12. The first activation unit is preferably designed as a button, which is operated by the driver and thus activates the device 10. The second activation unit 12 is the accelerator pedal of the vehicle. The accelerator pedal may be provided with an end switch, which detects the release of the accelerator pedal and the control and evaluation unit 10 provides this information by means of a signal. Alternatively, the release of the accelerator pedal can also be detected via engine torque values or drive torque variables. The control and evaluation unit 10 is further connected to vehicle dynamics regulations such as ABS, ASR, ESB or vehicle assistance systems or part of them. About the vehicle dynamics regulations 13 and over with these

Vehicle dynamics control 13 connected sensors 14, 15 receives the control and evaluation unit 10 driving condition information of the vehicle. This driving condition information may include information about the different tire / roadway combinations, that is, whether the vehicle is at high or low friction. About the vehicle dynamics control and the brake 21 assigned Raddrehzahlsensoren20 should be In addition, so-called μ-split driving situations can be determined and transmitted to the control and evaluation unit 10. If a temperature sensor is provided in the vehicle, a low friction situation can also be detected on the basis of the outside temperature in conjunction with the slip behavior of the vehicle. According to an alternative embodiment, no vehicle dynamics controls 13 are provided and the sensors are connected directly to the control and evaluation unit. In this case, the control and evaluation unit 10 determines the high or low friction value situation of the vehicle itself and does not assume it from the vehicle dynamics control system 13. The control and evaluation unit 10 is furthermore connected to a navigation system 16. The navigation system may be implemented as a NAVSTAR GPS in which four orbiting GPS satellites exist in each of six separate orbits. By means of the navigation system and the stored internal digital road map of the route guidance device of the vehicle, the absolute terrestrial position can be determined by the vehicle. The consideration of additional traffic information for the function of the internal digital road map contained vehicle-fixed route guidance device via a radio 17, which is connected to the evaluation and control unit 10. It is known that

Traffic information is transmitted in a standardized protocol. A location coding is used with which all traffic-relevant nodes of a country are listed, which are listed in a location table. In addition to the coding of the place contains the protocol a coding of the direction and the extent so as to define the area described by the traffic congestion. The traffic information is transmitted in the RDS system in addition to a broadcast and can be stored in the receiving device as a TMC signal (Traffic Message Channel), decoded and output in a suitable form. For any consideration of the traffic information by the route guidance device, the digital maps used in the route guidance device are provided with the details of the location table in order to be able to determine whether the route precalculated in the individual case is affected by current traffic information. The evaluation and control unit 10 is further connected to a traffic sign recognition 18 via data exchange lines.

A vehicle-mounted hands-free system 19 can be used as a voice control system and is also connected to the evaluation and control unit 10.

In addition, the AVS function may include a low cost proximity proximity sensor that can detect distances to objects. The sensor can easily be used to influence the AVS controlled braking if the vehicle is not equipped with an ACC system or the ACC system is deactivated.

The evaluation and control unit 10 operates as follows: The evaluation and control unit 10 receives information via the navigation system 16 in order to be able to determine the respective instantaneous position of the vehicle. For this purpose, a satellite navigation is combined with the evaluation of the vehicle sensors 20, 14, 15. As vehicle sensors come temperature sensors,

Raddrehzahlsensoren, steering angle sensors, yaw rate sensors and acceleration sensors and possibly Nahbereich- environment sensors into consideration. Furthermore, the navigation system contains at least one digital road map, which is part of the navigation system 16, for example as a CD-Rom. The internal digital road map of the navigation system is provided with information for a location coding, wherein the transmission of the route planning is done by the indication by the location coding in defined route sections that lie between the starting point and destination. Thus, the route planning can be coded in the smallest route sections, for example from intersection to intersection and in the evaluation and control unit in addition to the position of the vehicle and the vehicle TARGET position, namely the junction area of the road crossing the busy road are calculated. If the driver switches the button 11, the evaluation and control unit 10 releases the AVS function. The system is active. The vehicle is guided on the route by means of the steering movements and the control of the drive torque via the accelerator pedal by the driver. The evaluation and control unit 10 calculated as described above at predetermined intervals, the distance to the respective "end" of the road, that is, to the point which another street joins the route of the route. If the driver takes his foot off the gas as the second activation condition before an intersection or a similar end of a road, the evaluation and control unit 10 receives a second one

Activation signal describing the position of the accelerator pedal or a magnitude of the engine torque, for example, the idle speed. The evaluation and control unit 10 evaluates the second activation condition 12 as a request of the driver to stop at the crossing area. Based on the

Navigation Instrument is the current vehicle position and the vehicle TARGET position known. The

Navigation system sends via the bus a message to the evaluation and control unit 10, which includes the distance to a target position (standstill). In practice, a delay of 0.3g has been considered comfortable. This information is known to the control unit for the brakes. Based on the speed, the desired deceleration and the remaining distance can be calculated when the braking must be initiated.

Example: The vehicle drives to a crossroads at 100km away at 50km / h. This corresponds to a speed of 13.5m / s A delay of 0.3g is about 3m / s / s. This means that the vehicle needs 4.5s to come to a standstill with this delay. During this time a distance of 30m is covered. This means that in 70m from the current position the braking must be initiated with 0.3g. Since the navigation system continues to provide the distance to the intersection during braking, the control unit can check whether the required delay matches the required delay. If there is a deviation, the delay value can be corrected.

The desired delay is set by the brake control unit. The input information is the desired deceleration value and the wheel speeds of the wheels. From the wheel speeds of the wheels, the actual delay can be calculated. During ABS interventions, the delay needs to be extrapolated to advantage. A feedback PI controller can now be used to set a brake pressure to set the desired delay.

At the vehicle TARGET position or in the stopping point, the vehicle is kept stationary by the AVS function, in which the brake pressure is automatically maintained in accordance with a traction aid function. If an approach request of the driver is determined by the evaluation and control unit 10 by the driver operating the accelerator pedal, the brakes are released and switched back to the active function status.

The evaluation and control unit preferably incorporates traffic information via the radio 17 in the evaluation of the delay or the braking torque. Thus, congestion can be detected by means of a car-to-car communication, the affected vehicles can send corresponding information about their position to the evaluation and control unit 10 so that these in the calculation the delay or the braking torque can be considered and a shortened stopping distance can be specified. Furthermore, traffic sign recognition can also be taken into account as information so that priority roads or non-authorized roads can be recognized and taken into account when assessing the driver's request after the vehicle has been transferred from a driving state to a stationary state. Vehicle dynamics control systems and / or sensors provide the evaluation and control unit 10 with information by means of which the calculated braking torque or delays are modified.

In this way, corresponding vehicle TARGET positions can be maintained despite different slip conditions at high or low friction values. A modification of the braking torque or the delay can also be done via the operation of buttons and pedals on. For example, the cruise control lever can be used to influence the braking behavior of the vehicle. The driver has such an individual

Influence possibility over the strength of the braking force. An alternative possibility is the influence on the profile of the accelerator pedal operation. If the accelerator pedal has been released quickly, the car must also stop quickly. If the accelerator pedal is released slowly, the brake pressure is also modified accordingly. As another way of influencing so-called voice control systems can be used as in most vehicles nowadays speakerphones are installed, which have microphones. This allows commands from the driver when the function is switched on recorded and then evaluated with intelligent software in the evaluation and control unit 10. Thus, the driver can influence the stopping distance, commands "sharp braking", "slow braking", "stand in 100 meters" etc.

Claims

Patent claims

1. A method for automatically transferring a vehicle from a driving state to a stationary state comprising the steps of activating the method after a first predetermined activation condition activating the method after a second predetermined activation condition

Evaluating data of a navigation system with respect to a vehicle ACTUAL position and a vehicle TARGET position and determining a braking torque or a delay as a function of a size dependent on the vehicle positions to reach the stationary state of the vehicle at the vehicle TARGET position.

2. The method according to claim 1, characterized in that the first activation condition is a switch which is brought from a first position to a second position.

3. The method according to claim 1 or 2, characterized in that the second activation condition is the release of the accelerator pedal.

4. The method according to any one of claims 1 to 3, characterized in that supplementary traffic information for the

Determining the braking torque or the delay can be evaluated.

5. The method according to any one of claims 1 to 4, characterized in that supplementary driving state information for the determination of the braking torque or the delay are evaluated.

6. The method according to any one of claims 1 to 5, characterized in that

Setting means for modifying the determined braking torque or the delay are provided.