DE102008040631A1 - Method for distance and speed control of a motor vehicle and distance sensor - Google Patents

Abstract

The invention relates to a method for controlling the distance and speed of a motor vehicle (13) by means of a distance sensor (1) which detects objects (12) in the direction of travel in front of the vehicle (13) and has determined a preceding object (12) as the target object (12) in which values for the variables distance, relative speed and side angle of the target object (12) with respect to the controlled motor vehicle (13) can be stored and in which a stopping distance to the target object (12) can be predetermined, wherein at least one distance value to a first part (18 ) and a further distance value to a second part (15) of the target object (12) can be measured and stored and a distance sensor (1). The following method steps are used: A loss of the first part (18) is detected and a status bit is set and when the target object (12) stops, the controlled vehicle (13) stops depending on the distance value to the first part (18) of the distance value to the second part (15) and the relative speed of the second part (15).

Description

The The invention relates to a method for distance and speed control a motor vehicle by means of a distance sensor, the objects detected in front of the vehicle in the direction of travel and a preceding vehicle Object has been determined as the target object in which values for the Sizes distance, relative speed and if necessary Side angle of the target object with respect to the regulated Motor vehicle can be stored and in which a stopping distance is predeterminable to the target object, wherein at least one distance value to a first part and a further distance value to a second part Part of the target object can be measured and stored and a distance sensor.

From the DE 10 2004 046 873 A1 Such a method and such a distance sensor for distance and speed control of a motor vehicle are known. The distance sensor transmits cyclically radar or Lidarstrahlung, which are reflected by a fixed or preceding object. The radiation of one cycle or of successive cycles is reflected by different points of the object. Due to different reflection points, a size of the detected object can be determined and a classification can be carried out. In other words, reflection points move over the object over time or the reflection point jumps on an object surface. Reflection points are characterized by the variables relative velocity, side angle and distance of the detected object. Due to a same relative speed, a same side angle and a same distance, better a same relative speed, a nearly equal side angle and a nearly equal distance different reflection points can be assigned to a single object.

Has a vehicle by means of the distance sensor a preceding vehicle recognized as driving in its own lane and drives with adjusted speed behind this vehicle, so will the tracked vehicle as a relevant object, as a target or follower object, the speed-adjusted vehicle as ACC-controlled or regulated vehicle or briefly referred to as ACC vehicle.

In the distance sensor becomes five for the target object Values for the parameters distance, relative speed, Side angle to the ACC controlled vehicle, and width and length of the target object. For cost reasons a distance sensor is used which has a small opening angle in the vertical direction. Is a truck as a target object detected by the distance sensor, so may due to the structure of the Lorries both a rear surface a first part, as a rear surface or as a trailing edge referred to as well as another spaced from the trailing edge, detected further forward part under the truck detected be. Such a further forward arranged part, also as second Part designated is a tank, a tool box, a differential gear or an axle of the preceding truck not exceeding two meters from the trailing edge is spaced. In the distance sensor is the distance value that value for the part of the target object stored closest to the regulated vehicle is. If you drive too close, you have a high rear edge lost. The trailing edge of the first part is no longer from detected by the distance sensor. The loss of the trailing edge is noticeable. As a distance value to the target object, a value is then used and stored, one of the trailing edge nearest Part is associated. This is, for example, the toolbox, Also referred to as a tool container, which is one meter from the rear edge is removed, or the differential gear, the 2 meters from the trailing edge. In the memory of the distance sensor the distance value to the first part is overwritten and get lost. This is an exchange of distance values inside the memory of the distance sensor instead, the exchange is also called a migration of the distance value. It's from therefore set a stopping distance of five meters, so that of the distance sensor, so the ACC-controlled vehicle when stopping the target object, ie the truck in at least three meters, maximum five meters distance to Truck comes to a stop. Although the stopping distance to the stopped target object in the memory of the distance sensor with 5 meters, the actual distance varies to the stopped target object. An actual distance from three meters to the stopped vehicle is perceived as comfortable. But behind a motor vehicle or a truck with the trailing edge down, so is an actual one Distance of 5 meters respected. The actual distance of 5 meters is perceived as uncomfortable too big. Other vehicles overtake and shear in front of the ACC Vehicle.

Of the Invention is therefore the object of an improved Provide distance sensor and an improved method by means of which a comfortable distance is adjustable.

This object is achieved with the features of the main claims. The method according to the invention comprises the following method steps: A loss of the first part is detected and a status bit is set, and when the target object stops, the controlled vehicle stops as a function of time of the distance value to the first part, the distance value to the second part and the relative speed of the second part. If the first part is no longer detected by the distance sensor, then a loss of the first part is detected and set in the distance sensor, a status bit, called English flag bit. The last measured distance value or last measured distance values between the first part of the target object and the controlled motor vehicle are retained. The regulated motor vehicle is then close behind the target object. If the target object stops, the regulated vehicle also stops. Relative speeds and distance values to different parts of the target object can be stored in the distance sensor. From the relative speed and the distance value, an absolute speed in connection with the speed of the ACC-regulated motor vehicle can be determined from a single component or both components. By means of the relative speed alone or by means of the relative speed and the distance value, relative accelerations and absolute accelerations for the various parts can be derived. All of these quantities and values are provided in different programming levels of the distance sensor and are used individually or in conjunction with each other for controlling the ACC-controlled motor vehicle, thus also for stopping the controlled motor vehicle. In a first alternative, a difference between the first and the second part of the target object is calculated and, starting from the distance to the second part, a comfortable distance is set. In a second alternative, only the speed of the second part is observed, and when the target object is stopped, the last measured distance value is used to maintain the comfortable distance. Advantageously, the last measured or one of last measured distance values is used. Alternatively, a mean value which takes into account the last measured distance values is used as the distance value to the first part. This minimizes errors in the distance calculation.

In Advantageously, the stopping distance is dependent can be specified from the first part. This takes into account the circumstance that in a truck with lowered trailing edge of the Stopping distance, also referred to as nominal stop distance, not corrected must become.

In Advantageously, the stopping distance is a value between two and four meters, advantageously between two and a half and three and a half meters, in particular with three meters predeterminable. A stopping distance of three meters is perceived as comfortable.

In Advantageously, depending on the status bit, a Difference between the first and the second part of the predeterminable Distance added. This is at loss of the first part and captured second part compensated to always the comfortable Stopping distance of three meters.

increases the distance between the ACC controlled motor vehicle and the Target object, so a recognition of the trailing edge is not given. In addition, an uncertainty increases over time a pursuit of the captured second part. In an advantageous manner Way is the target stopping distance of therefore after a predetermined Period of time to four to six meters, in an advantageous manner 5 meters to enlarge.

To the better understanding of the invention are below embodiments explained in more detail with reference to the drawing.

It demonstrate

1 a block diagram of a distance sensor,

2 an ACC-regulated motor vehicle and a plurality of parts of a truck identified as a target object detected by the distance sensor of the motor vehicle, in a schematic illustration,

3 the ACC-regulated motor vehicle and a plurality of parts of the target object, which are arranged below the target object and are detected by the distance sensor of the motor vehicle, in a schematic representation,

4 a distance-time diagram for various arranged on the target object and detected by the distance sensor of the motor vehicle parts and

5 the ACC-controlled motor vehicle and a detected by the distance sensor of the motor vehicle lower trailing edge of a recognized as a target truck in a schematic representation.

In The different figures are similar or the same Elements designated by like reference numerals.

1 shows a distance sensor 1 with a distance and speed control device 2 that has an input circuit 3 and an object sensor 4 having. By means of the input circuit 3 are the distance and speed control device 2 , also as a distance and speed controller 2 designates, input signals can be fed. As input signals are measured variables of the object sensor 4 provided that works with a radar or laser radiation. This object sensor 4 emits electromagnetic waves reflected from objects in front of the ACC-controlled vehicle. Reflected radiation is emitted by the object sensor 4 received again. Based on the signal propagation time of the electromagnetic waves and the Doppler shift of the radiations, the distance between the ACC-controlled vehicle and the preceding object, the relative speed of the preceding object with respect to the ACC-controlled vehicle, and the side angle of the preceding object with respect to a sensor main axis of the distance sensor 1 determined. The input circuit 3 For example, measured quantities are supplied to objects located within the sensor detection area with respect to each reflection point. It is possible that only one or more reflection points are measured per detected object. The membership of several reflection points to a single object can be detected by means of equal relative velocities for the different reflection points as well as on the same side angles and distances. Furthermore, the input circuit 3 a speed signal of a speed sensor 5 supplied, which represents the speed of the ACC-regulated, so the own vehicle. This makes it possible, the relative speed, the object sensors 4 measures and makes available to convert into absolute values. Furthermore, the input circuit 3 Signals of an operating device 6 be fed, by means of the motor vehicle driver of the ACC-controlled vehicle, the distance and speed controller 2 on and off, as well as driver-specific system settings to make the distance and speed controller 2 to adjust according to his wishes. The input circuit 3 of the distance and speed controller 2 supplied input signals are by means of a data exchange device 8th to a calculating device 7 forwarded. The calculation device 7 , which can be executed for example as a microprocessor or signal processor, determined from the input signals supplied to it output signals that can be output to downstream elements. The inventive method is, for example, as a program code in the calculation device 7 stored in the process according to the invention, the input signals are processed. The calculation device 7 determined in response to the input signals supplied to it actuating signals by means of the data exchange device 8th to the output circuit 9 to get redirected. The output circuit 9 forwards these actuating signals to downstream actuating devices, wherein in the case of a calculated acceleration requirement, a power-determining control element 10 an internal combustion engine is controlled. The power-determining control element 10 The drive device can be, for example, as an electrically controllable throttle valve or as an electrically controlled fuel quantity measuring device of a fuel injection system. Is by the calculation device 7 determines a delay requirement of the own vehicle, so gives the output circuit 9 Control signals to the delay devices 11 the vehicle continues. These are transmitted by means of an electrically controllable brake booster to the vehicle brakes, which delay the vehicle according to the control signals.

2 shows a truck 12 that of a distance sensor 1 a subsequent ACC-regulated motor vehicle 13 captured and as a target object 12 is determined. Both vehicles 12 and 13 drive at low speed. The truck 12 has a structure 14 , a cuboid container 15 below the construction 14 and wheels 16 on an axis. A right end of the container 15 is at a distance 17 from a meter from a trailing edge 18 of the construction 14 , the axis of the rear wheels 16 is at a second distance 19 from two meters from the trailing edge 18 arranged. The ACC-regulated motor vehicle 13 has a third distance 20 from more than eight meters to the truck 12 on. The distance sensor 1 captures the trailing edge 18 , the container 15 and the axle of the truck 12 , Due to a same speed, the three parts become as to the truck 12 , ie as an object 12 associated detected. The distances of the various parts to the ACC-controlled motor vehicle 13 are saved. Radar or lidar radiation of the distance sensor 1 becomes under a vertical opening angle 21 broadcast. At a fourth distance 22 from about six to eight meters to the preceding truck 12 loses the distance sensor 1 the trailing edge 18 ,

3 shows the ACC-controlled vehicle 13 at a fifth distance 23 from three meters behind the truck 12 , Due to the small vertical opening angle 21 now only the container 15 and the axis of the wheels 16 from the distance sensor 1 detected. Stops the truck 12 , comes the motor vehicle 13 at a fifth distance 23 from three meters behind the truck 12 to a halt.

4 FIG. 13 shows distances sR1, sB1 and sK1 to sRn, sBn and sKv measured at different times t1 to tn from the distance sensor 1 to the axle of the wheels 16 to the container 15 and to the trailing edge 18 be measured. The distance 17 corresponds to the distance between sB3 and sK3, the second distance 19 corresponds to the distance between sR7 and sK7. At the time tv loses the Ab level sensor 1 the contact with the trailing edge 18 ,

5 shows the truck 12 with a rear bumper 24 and the motor vehicle 13 that at a sixth distance 25 from three meters to the stationary truck 12 comes to a standstill.

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 102004046873 A1 [0002]

Claims (10)

Method for adjusting the distance and speed of a motor vehicle ( 13 ) by means of a distance sensor ( 1 ), objects ( 12 ) in the direction of travel in front of the vehicle ( 13 ) and a preceding object ( 12 ) as the target object ( 12 ) in which values for the distance and relative velocity variables of the target object ( 12 ) with regard to the regulated motor vehicle ( 13 ) are storable and in which a stopping distance to the target object ( 12 ), wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, comprising the following steps: - a loss of the first part ( 18 ) is determined and set a status bit and - when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ), the distance value to the second part ( 15 ) and the relative speed of the second part ( 15 ). Method for adjusting the distance and speed of a motor vehicle ( 13 ) by means of a distance sensor ( 1 ), the objects 12 in the direction of travel in front of the vehicle 13 captured and a preceding object 12 as a target object 12 has determined in the values for the sizes distance, relative speed and side angle of the target object 12 with regard to the regulated motor vehicle ( 13 ) are storable and in which a stopping distance to the target object 12 can be predetermined, wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, comprising the following steps: - a loss of the first part ( 18 ) is determined and set a status bit and - when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ) and the distance value to the second part ( 15 ). Method for adjusting the distance and speed of a motor vehicle ( 13 ) by means of a distance sensor ( 1 ), objects ( 12 ) in the direction of travel in front of the vehicle ( 13 ) and a preceding object 12 as target object ( 12 ) in which values for the distance and relative velocity variables of the target object ( 12 ) with regard to the regulated motor vehicle ( 13 ) are storable and in which a stopping distance to the target object ( 12 ), wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, comprising the following steps: - a loss of the first part ( 18 ) is determined and set a status bit and - when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ) and the relative speed of the second part ( 15 ). Method according to one or more of the preceding claims 1 to 3, characterized in that the stopping distance as a function of the first part ( 18 ) can be specified. Method according to one or more of the preceding Claims 1 to 4, characterized in that the stopping distance with a value between two and four meters, advantageously between two and a half and three and a half meters, especially with three meters can be specified. Method according to one or more of the preceding claims 1 to 5, characterized in that a difference between the first and the second part ( 15 . 18 ) is added to the predetermined distance. Method according to one or more of the preceding Claims 1 to 6, characterized in that the stopping distance After a predetermined period of time to a value of four to six Meters can be advantageously increased to five meters is. Distance sensor ( 1 ) for the distance and speed control of a motor vehicle ( 13 ), objects ( 12 ) in the direction of travel in front of the vehicle 13 detected and a preceding object ( 12 ) as the target object ( 12 ) in which values for the distance and relative velocity variables of the target object ( 12 ) with regard to the regulated motor vehicle ( 13 ) are storable and in which a stopping distance to the target object ( 12 ), wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, characterized in that a loss of the first part ( 18 ) and a status bit in the distance sensor ( 1 ) is settable and when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ), the distance value to the second part ( 15 ) and the relative speed of the second part ( 15 ). Distance sensor ( 1 ) for the distance and speed control of a motor vehicle ( 13 ), objects ( 12 ) in the direction of travel in front of the vehicle 13 detected and a preceding object ( 12 ) as the target object ( 12 ) in which values for the distance and relative velocity variables of the target object ( 12 ) with regard to the regulated motor vehicle ( 13 ) are storable and in which a Abhalteab stood to the target object ( 12 ), wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, characterized in that a loss of the first part ( 18 ) and a status bit in the distance sensor ( 1 ) is settable and when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ) and the distance value to the second part ( 15 ). Distance sensor ( 1 ) for the distance and speed control of a motor vehicle ( 13 ), objects ( 12 ) in the direction of travel in front of the vehicle 13 detected and a preceding object ( 12 ) as the target object ( 12 ) in which values for the distance and relative velocity variables of the target object ( 12 ) with regard to the regulated motor vehicle ( 13 ) are storable and in which a stopping distance to the target object ( 12 ), wherein at least one distance value to a first part ( 18 ) and another distance value to a second part ( 15 ) of the target object ( 12 ) are measurable and storable, characterized in that a loss of the first part ( 18 ) and a status bit in the distance sensor ( 1 ) is settable and when stopping the target object ( 12 ) stops the controlled vehicle ( 13 ) depending on the distance value to the first part ( 18 ) and the relative speed of the second part ( 15 ).