Method and apparatus for lane control of a vehicle

Abstract

Apparatus for controlling dynamics of a vehicle determines a current course angle (α) of the vehicle. A desired course angle (α.sub.psi) is defined and assigned to a first point on a temporal profile of a desired driving line. The first point is on the desired driving line at a first preview time from a location assigned to an instantaneous vehicle position. A course angle deviation of the current course angle (α) from the desired course angle (α.sub.psi) is determined. A target angle (α.sub.ta) is defined and assigned to a second point on the temporal profile of the desired driving line. The second point is on the desired driving line at a distance of a second preview time from the location. A steering wheel angle (δ) is determined as a total of the target angle (α.sub.ta) reinforced with a first parameter and the course angle deviation reinforced with a second parameter.

Claims

1. An apparatus (300) for controlling the lateral dynamics of a vehicle, the apparatus (300) comprising: a detection device (302), an output device (304) and a computing device (306), the detection device (302) being configured to detect or to determine a current course angle (α) of the vehicle, the output device (304) being configured to output a steering wheel angle (δ) with which the vehicle is controllable, and the computing device (306) being configured to define a desired course angle (α.sub.psi) that is assigned to a first point (120) on a temporal profile of a desired driving line (110), the first point (120) being arranged on the desired driving line (110) at a distance of a first preview time (T.sub.PreviewYaw) from a location (116) assigned to an instantaneous vehicle position, and the computing device (306) being configured to determine a course angle deviation (α.sub.psi−α) of the current course angle (α) from the desired course angle (α.sub.psi) and to define a target angle (α.sub.ta) that is assigned to a second point (124) on the temporal profile of the desired driving line (110), the second point (124) being arranged on the desired driving line (110) at a distance of a second preview time(T.sub.PreviewXY) from the location (116), and the computing device (306) being configured to determine the steering wheel angle (δ) in accordance with a sum total of the target angle (α.sub.ta) amplified by a first parameter (P.sub.ta) and of the course angle deviation (α.sub.psi−a) amplified by a second parameter (P.sub.psi), the first parameter and the second parameter being known information pertaining to vehicle performance.

2. The apparatus (300) of claim 1, wherein the computing device (306) is configured to define the first preview time (T.sub.PreviewYaw) and to determine the first point (120) on the desired driving line (110), the first point being at a distance of the first preview time (T.sub.PreviewYaw) from the location (116) and to define the second preview time (T.sub.PreviewXY), and to determine the second point (120) on the desired driving line (110), the second point being at a distance of the second preview time (T.sub.PreviewXY) from the location (116).

3. The apparatus (300) of claim 2, wherein the computing device (306) is configured to determine a direction (128) from a point with a fixed geometrical reference with respect to the vehicle, in particular from a center of gravity (112) or front axle center point of the vehicle in accordance with a model (102) of the vehicle or from a driver's position to the second point (124), and to determine the target angle (α.sub.ta) in accordance with an angle by which the direction (128) deviates from a vehicle longitudinal axis (106) in accordance with the model (102) of the vehicle.

4. The apparatus (300) of claim 1, further comprising an input device (308) for inputting the first parameter (P.sub.ta) and/or the second parameter (P.sub.psi) and/or the first preview time (T.sub.PreviewYaw) and/or the second preview time (T.sub.PreviewXY).

5. A method for controlling lateral dynamics, of a vehicle, the method comprising: detecting a current course angle (α) of the vehicle; defining a desired course angle (α.sub.psi) that is assigned to a first point (120) on a temporal profile of a desired driving line (110), the first point (120) being on the desired driving line (110) at a distance of a first preview time (T.sub.PreviewYaw) from a location (116) assigned to an instantaneous vehicle position; determining a course angle deviation (α.sub.psi−α) of the current course angle (α) from the desired course angle (α.sub.psi); defining a target angle (α.sub.ta) assigned to a second point (124) on the temporal profile of the desired driving line (110), the second point (124) being arranged on the desired driving line at a distance of a second preview time (T.sub.PreviewXY) from the location (116); determining a steering wheel angle (δ) in accordance with a sum total of the target value (α.sub.ta) amplified by a first parameter (P.sub.ta) and of the course angle deviation (α.sub.psi−α) amplified by a second parameter (P.sub.psi), the first parameter and the second parameter being known information pertaining to vehicle performance; and outputting the steering wheel angle (δ).

6. The method of claim 5, further comprising: defining the first preview time (T.sub.PreviewYaw); determining the first point (120) on the desired driving line (110), the first point (120) being at a distance of the first preview time (T.sub.PreviewYaw) from the location (116); defining the second preview time (T.sub.PreviewXY); and determining the second point (124) on the desired driving line (110), the second point being at a distance of the second preview time (T.sub.PreviewXY) from the location (116).

7. The method of claim 6, further comprising: determining a direction (128) from a point with a fixed geometrical reference with respect to the vehicle in accordance with a model (102) of the vehicle or from a driver's position to the second point (124); and determining the target angle (α.sub.ta) in accordance with an angle by which the direction (128) deviates from a vehicle longitudinal axis (106) in accordance with the model (102) of the vehicle.

8. The method of claim 5, further comprising identifying an input, and determining the first parameter (P.sub.ta) and/or the second parameter (P.sub.psi) and/or the first preview time (T.sub.PreviewYaw) and/or the second preview time (T.sub.PreviewXY) in accordance with the input.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagrammatic illustration of controller variables.

(2) FIG. 2a is a diagrammatic illustration of a course angle deviation.

(3) FIG. 2b is a diagrammatic illustration of a target angle deviation.

(4) FIG. 3 is a diagrammatic illustration of a lane controller.

(5) FIG. 4 is a flow chart that shows the steps of a method in accordance with one embodiment of the invention.

DETAILED DESCRIPTION

(6) FIG. 1 illustrates control variables of a lane controller in a model 100 using the example of a single track model 102 of a vehicle. The single track model 102 has a first wheel 104 and a second wheel 108. The second wheel 108 is steerable by a steering angle δ with respect to a vehicle longitudinal axis 106. A desired driving line 110 is defined for the vehicle 102. A different model of the vehicle may also be used.

(7) In the example, a center of gravity 112 of the vehicle in the single track model 102 is arranged with respect to the desired driving line 110 on the vehicle longitudinal axis 106 between the wheels and offset from the desired driving line 110 by a distance 114. A perpendicular to the desired driving line 110 leads through a location 116 on the desired driving line 110, with the location 116 being assignable to an instantaneous position of the vehicle, and through the center of gravity 112. The distance 114 defines a transverse deviation of the vehicle from the desired driving line 110.

(8) FIG. 1 shows a first preview period 118 for a desired course angle α.sub.psi at a first point 120, and a second preview period 122 for a target angle α.sub.ta at a second point 124, on the desired driving line 110. In FIG. 1, the second point 124 is farther from the location 116 in a direction of travel of the vehicle 102 than the first point 120. However, the second point 124 does not have to be farther from the location 116 than the first point 120. The preview periods can be selected as desired, and thus the first point 120 and the second point 124 do not have to be arranged in a fixed sequence on the desired driving line 110. The first point 120 and the second point 124 may lie one above the other. The first point 120 can be farther from the location 116 than the second point 124.

(9) A first preview time T.sub.PreviewYaw specifies a duration of the first preview period 118. By way of example, FIG. 1 illustrates a course 126, i.e. a desired orientation of the vehicle longitudinal axis 106, at the first point 120 as a tangent to the desired driving line 110 at the first point 120. A second preview time T.sub.PreviewXY specifies a duration of the second preview period 122. A viewing direction 128 of a driver of the vehicle to a target point on the desired driving line 110 is illustrated in FIG. 1 by way of example as the section from the center of gravity 112 to the second point 124.

(10) The two separate preview times T.sub.PreviewYaw and T.sub.PreviewXY facilitates a simulation of a reaction time of the vehicle, the viewing direction of a human driver and the knowledge of the human driver about a vehicle performance.

(11) In the example, the points of the desired driving line 110 are defined in the form of a table of values. In the table of values, the following is assigned to a point on the desired driving line 110:

(12) Distance from the location 116 of the vehicle along the desired driving line 110, course angle α, x-coordinate of the point, y-coordinate of the point.

(13) In the example described and illustrated herein, the control by the lane controller is parameterized and influenced by the following four parameters: first preview time T.sub.PreviewXY first P component P.sub.ta, second preview time T.sub.PreviewYaw, second P component P.sub.psi.

(14) For the course angle α and the desired course angle α.sub.psi, FIG. 2a diagrammatically illustrates a course angle deviation (α.sub.psi−a) between the vehicle longitudinal axis 106 and the course 126.

(15) FIG. 2b diagrammatically illustrates the target angle deviation α.sub.ta between the vehicle longitudinal axis 106 and the viewing direction 128.

(16) The steering wheel angle δ required for maintaining the desired driving line 110 is then defined by the lane controller as follows:
δ=α.sub.ta*P.sub.ta+(α.sub.psi(T.sub.PreviewYaw)−α)*P.sub.psi
This lane controller is usable for lane control, i.e. lateral control, in vehicle simulation models or in circuit simulations. This lateral control on the vehicle also may be used within the scope of a prototypical implementation.

(17) It is advantageous that only P controllers are required for the lateral control. Owing to a corresponding performance of the vehicle, the control quality is nevertheless high. This lane control functions even in vehicle movement dynamics situations.

(18) FIG. 3 diagrammatically illustrates a lane controller 300. The elements shown in FIG. 3 and described elsewhere in this disclosure may be implemented in various forms of hardware, software or combinations thereof. Preferably, these elements are implemented in a combination of hardware and software on one or more appropriately programmed general-purpose devices that may include a processor, memory and input/output interfaces. The term “connected” as used herein and implied by FIG. 3 is defined to mean directly connected to or indirectly connected through one or more intermediate components. Such intermediate components may include both hardware and software-based components.

(19) It will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry, hardware and software embodying the principles of the disclosure. Similarly, any functions or methods implied by these block diagrams may be represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. The lane controller 300 comprises a detection device 302 that is configured to detect or to determine a current course angle α. The detection device 302 may comprise sensors incorporated into the vehicle for sensing the steering wheel angular alignment, the alignment of the second wheel 108 as well as cameras or positioning devices incorporated into the vehicle.

(20) The lane controller 300 of FIG. 3 comprises an output device 304 that is designed to output the steering wheel angle δ. The output device may include a dashboard display and/or communication hardware and/or communication software. The lane controller 300 also comprises a computing device 306 that may communicate with the output device and is configured to determine the steering wheel angle δ in accordance with the current course angle α of the first preview time T.sub.PreviewXY the first P component P.sub.ta, the second preview time T.sub.PreviewYaw and the second P component P.sub.psi. As noted above, the computing device 306 may be implemented as a combination of hardware and software on one or more appropriately programmed general-purpose devices that may include a processor, memory and input/output interfaces.

(21) The computing device 306 that is configured to determine the steering wheel angle δ in accordance with the current course angle α of the first preview time T.sub.PreviewXY the first P component P.sub.ta, the second preview time T.sub.PreviewYaw and the second P component P.sub.psi will be described below for the location 116 on the desired driving line 110, onto which the perpendicular through the center of gravity 112 falls. In the illustrated and/or described example, the location 116 is assigned an instantaneous position of the vehicle that is controlled by the lane controller 300.

(22) The computing device 306 is configured to define, for the location 116, the desired course angle α.sub.psi that is assigned to the first point 120. The first point 120 is arranged on a temporal profile of the desired driving line 110 at a distance of the first preview time T.sub.PreviewYaw from the location 116.

(23) The computing device 306 is configured to determine the course angle deviation α.sub.psi−α of the current course angle α from the desired course angle α.sub.psi.

(24) The computing device 306 also is configured to define the target angle α.sub.ta for the second point 124. On the temporal profile of the desired driving line 110, the second point 124 is arranged at a distance of the second preview time T.sub.PreviewXY from the location 116 on the desired driving line. The computing device 306 is configured to determine, as the target angle α.sub.ta an angle that the viewing direction 128 and the vehicle longitudinal axis 106 enclose for the points.

(25) The computing device 306 is configured to determine the steering wheel angle δ in accordance with a sum total of the target angle α.sub.ta reinforced with the first parameter P.sub.ta and of the course angle deviation α.sub.psi−α reinforced with a second parameter P.sub.psi.

(26) In addition, the lane controller 300 can comprise an input device 308 for inputting the first P component P.sub.ta and the second P component P.sub.psi and/or the first preview time T.sub.PreviewYaw and/or the second preview time T.sub.PreviewXY The input device 308 may comprise appropriate known hardware, wired or wireless interconnections or interfaces and/or appropriate software. As a result, the lane controller 300 is adjustable in a particularly simple manner.

(27) The lane controller 300 also can carry out, for example, the method described below with reference to FIG. 4.

(28) In a parameterizing operation, an optional step 400 can be provided for the method shown in FIG. 4. In the step 400, for example for parameterizing the lane controller 300, an input is identified defining values for the first parameter P.sub.ta, the second parameter P.sub.psi, the first preview time T.sub.PreviewYaw and/or the second preview time T.sub.PreviewXY

(29) In this case, the first parameter P.sub.ta and/or the second parameter P.sub.psi and/or the first preview time T.sub.PreviewYaw and/or the second preview time T.sub.PreviewXY can be determined in accordance with the input.

(30) As a result, the lane controller 300 can be parameterized in a simple manner.

(31) Step 402 includes determining a current course angle α of the vehicle at the location 116 and assigning the current course angle α to the instantaneous vehicle position. The current course angle α can be measured or calculated from measured signals.

(32) Step 404 includes defining the first preview time T.sub.PreviewYaw and determining the first point 120 on the desired driving line 110. The first point 120 is arranged on the desired driving line 110 at a distance of the first preview time T.sub.PreviewYaw from the location 116.

(33) Step 404 includes defining the second preview time T.sub.PreviewXY and determining the second point 124 on the desired driving line 110. The second point 124 is at a distance of the second preview time T.sub.PreviewXY from the location 116.

(34) Step 404 includes defining the desired course angle α.sub.psi that is assigned to the first point 120.

(35) Step 406 includes determining a course angle deviation α.sub.7−α of the current course angle α from the desired course angle α.sub.psi.

(36) Step 408 includes defining a target angle α.sub.ta that is assigned to the second point 124. The illustrated and described example includes determining the viewing direction 128 from the center of gravity 112 of the vehicle in accordance with the single track model 102 to the second point 124. However, the method can include determining a direction to the second point 124 starting from any other point with a fixed geometrical reference with respect to the vehicle. Examples of other points are a front axle center point of the vehicle or a driver's position in accordance with the model 102 of the vehicle. The target angle α.sub.ta is determined in accordance with the angle by which the viewing direction 128 deviates from an orientation of the vehicle longitudinal axis 106 at the location 116 in accordance with the single track model 102 of the vehicle.

(37) Step 410 includes determining the steering wheel angle δ. The steering wheel angle δ is determined in accordance with a sum total of the target angle α.sub.ta reinforced with a first parameter P.sub.t, and of the course angle deviation α.sub.psi−α reinforced with a second parameter P.sub.psi.

(38) The steering wheel angle δ is output in a subsequent step 412. The vehicle subsequently is controlled, in a step 414, with the steering wheel angle δ.

(39) Subsequently, for example in the event of the parameterization process, the step 402 or otherwise the step 404 is carried out. The method ends, for example, when the lane control is ended.