DE2256915A1 - METHODS OF MEASURING, CONTROLLING AND / OR DISPLAYING THE MOVEMENT OF LAND VEHICLES - Google Patents

Description

Method for measuring, regulating and / or indicating the movement of Land vehicles The invention relates to methods for measuring, regulating and / or displaying the movement of land vehicles in relation to preferably unmarked surroundings and Facilities for carrying out these procedures.

Such methods and devices are already known per se. Included a distinction must be made between procedures that relate to anti-lock protection, those that cause undesired changes in direction due to an intervention in the control system compensate, as well as those that provide information about the behavior of other road users display and Ln dangerous situations in the control, braking or drive system automatically intervention.

On the other hand, it is a very important measure to increase road safety the measurement of the distance to the vehicle in front and generation of warning and Control signals when the speed of your own vehicle is undershot related safety distance. Known systems that are without-street-mounted Aids get by have — in principle — disadvantages because of the straight-line propagation which is the graining rays (IR, radar, laser) in question for the distance measurement a distance measurement in curves and crests cannot be carried out. In addition, there is the risk of oncoming traffic, trees, roadsides, bridges and the like. The measurement distort. As a remedy is only known road and foreign vehicles with special to provide complex auxiliary equipment.

The object of the present invention is therefore to provide methods and devices of the type mentioned to create, which by direct contactless distance measurement in relation to unmarked surroundings, e.g. obstacles on the roadway, the disadvantageous Avoid the uncertainties of known procedures and make them particularly easy and can be realized more economically. This object is achieved according to the invention solved in that for the purpose of measuring the distance between the vehicle and a obstacle in the direction of travel using at least one optical, a grid in an image plane and at least one assigned to this grid, the grating scanning photoelectric receiver having, as well as mechanical Movement of an optical component or through polarizing or color splitting optical components or by a corresponding offset of two grids or grid structures a correlator system generating signals containing directional information Image structure of the obstacle is detected and from the amplitudes of the output signals of the correlator system the distance or its change, from the frequency and the The phase position of these signals, on the other hand, is the relative speed transverse to the direction of travel between vehicle and obstacle can be obtained after a comparison with the Gene speed of one's own biitzeuga over ground one the speed of one's own Pikrzeuga influencing servo system and / or a display and / or warning device are fed.

For the purpose of detecting the approach speed the following Vehicles will use a rear-facing optical, at least a grid in an image plane and at least one assigned to this GX ter, having photoelectric receivers scanning the grating Correlator system at least one image structure of the following vehicle is detected and the approach speed as well as the distance of the following vehicle proportional signals are generated, after a comparison with the speed of one's own vehicle, a display and / or warning device are supplied.

A device for measuring the distance between the vehicle and a The obstacle in the direction of travel comprises a direction-of-travel obstacle optical, preferably at least suitable for measurement in two coordinate directions a grid in an image plane and at least one assigned to this grid, the grating scanning photoelectric receiver having, as well as for example by mechanical movement of an optical component or by polarizing resp. Optical components splitting up according to color containing directional information Correlator system generating signals, which utilizes the perspective of the object and their change, the electrical output signals obtained, each perpendicular to the viewing direction running coordinate direction fed to a downstream comparison stage will. This comparison stage comprises a summing stage, a differential stage and / or ratio-forming stage, this comparison stage being followed by an arithmetic unit is to which signals from a distance measuring system are additionally fed. At the output of the arithmetic unit there is an influencing speed of the vehicle Servo system and / or a display and / or warning system connected.

To record the approach speed of following vehicles, is an optical, at least one, which is directed backwards with its line of sight Grid in an image plane as well as at least one assigned to this grid, the Grid Correlator system comprising scanning photoelectric receivers provided, its electrical output signals together with the speed the own vehicle proportional electrical signals of a comparison device are fed, which is followed by a warning device.

Embodiments of devices for carrying out the above-described Processes are shown schematically in the drawings and described below. 1 and 1a show an optical correlator system which provides directional information containing two-coordinate signals generated, Fig. 2 sketches to explain a Anti-collision device, Fig. 3 the functional diagram of a device with optical Correlation systems to avoid collisions with those in the direction of travel Obstacles.

In Figure 1, the reference numeral 1 denotes a moving object, whose relative speed is to be measured. This object 1 is from a Lamp 2 illuminated via a condenser 3. An objective 4 forms the object 1 in the plane of a grid 25 from. The grid 25 consists of on a support 26 in a large number of existing similar, with the edges of their bases parallel to each other and adjacent pyramids 27. Through the normals of the pyramid surfaces two pairs of directions are defined in the plane of the grating, four of which are photoelectric Receiver 28-31 with four Kondeusoren 32-39 are assigned.

Since the object structure, as on the object 1, by dark areas indicated that the light reflects different degrees, contain the output signals of the photocells 28-31 change the brightness distribution over time in the plane of the grid 25 as a result of the movement of the object 1. By the superposition the object structure with the structure of the grid results in a filtering out of the Image structure components whose spatial frequency corresponds to the lattice constant. Be there additional lower-frequency image components are allowed to pass through as a disruptive constant light component. With the aid of this grid arrangement, a push-pull signal pair can be obtained for each coordinate direction to win. An elimination is obtained by forming the difference between each pair of signals the in-phase constant light components and an addition of the anti-phase signal components the filtered spatial frequency. When moving the object relative to the grid, then, as is known, the spatial frequency in speed-proportional time frequency implemented and measured. As indicated, a drive 15 is present, the such engages the movably mounted grid 25 that this is perpendicular to the optical axis and is preferably moved in the direction of the diagonal of its grid elements. Does if this is the case, one also obtains when the object is stationary at the output of the receiver a time frequency which, depending on the direction of movement of the object, is either the sum or is proportional to the difference between the speed of movement of the object and the speed of the grid.

These signals can be compared in a known manner with a signal derived only from the grid movement (e.g. by means of a phase-sensitive Rectifier) determine the size and direction of the object movement. Should the location are measured, the number of continuous periods must be at the output of the comparator can be counted taking into account the directional information that is also available. Of course, it is possible to assign each of them to a coordinate direction to replace the photoelectric receiver with a single photoelectric receiver, alternating between the two, for example by means of an oscillating mirror Send directions of leaving the grid Assigned to the bundle of rays is. The signal quality of the correlator system can be improved in that the object structures that mainly contribute to signal generationXund have large spatial frequency components in the measuring direction, compared to other object structures preferred in their sharpness of image. This is in a device according to the invention realized for two-coordinate measurement according to FIG. The surface of a traffic route 1 is illuminated by a lamp 2 via a condenser 3. An objective 4 forms the traffic route 1 into the level of a pyraxide grid 25. In the entrance pupil of the lens 4 a cross-slit diaphragm 6 is arranged, the slots of which are parallel to the pyramid sides of the grid 25 and thus to the measuring directions. the The light fluxes penetrating the grid 25 are via a common condenser 32 are each supplied to a pair of photoelectric receivers 28, 29 and 30, 31. The processing the resulting signals at the receivers is the same as in Fig.l facility shown. It has been shown that this improves the signal by the Factors 3 and larger are possible.

Instead of generating direction signals with the help of the drive 15, which can swing the grid 25 in the direction of one of its diagonals a stationary arrangement can also be chosen. In this case the grid is stationary mounted and a polarizing splitter (e.g. a Wollaston prism) in the beam path inserted in such a way that its direction of splitting coincides with the direction of a diagonal of the Grid matches.

With the aid of FIGS. 2a-2d, basic points of view are given below the distance measurement explained. Leave alone by means of distance measuring assemblies the problems of distance measurement of vehicles cannot be solved, since the Distances to obstacles that are not on would be measured Collision course (e.g. oncoming vehicles, roadside in curves, etc.) As a result, it must Additional information can be derived, both on the approach speed as well as the lateral movement of the obstacle: in the figures 2a and 2c show an obstacle which is on a collision course.

This is expressed in the picture impression by the fact that the contours and Structures of the obstacle symmetrical to the one indicated by the "crosshairs" Line of sight 'grow' In Figures 2b. And 2d, however, the 'growth is a lateral Image shift superimposed, the obstacle is e.g.

a vehicle that is currently being overtaken and is therefore no longer on a collision course lies.

The growth of the image structures together with the distance gives the Approach speed, the lateral displacement of the image along with the Distance is the side speed of the obstacle. The ratio of both speeds in addition to the size and distance of the obstacle, the question of whether there is a risk of collision or not.

When cornering, for example, although a certain distance (and thus the direction of travel) the opposite side of the road is an obstacle, but that moves out of sight at a certain lateral speed (Fig.2e). The approach speed v a is only one component of the relative movement, and the side speed v5 shows the observer that there is no risk of collision consists.

From these considerations one recognizes that in addition to the distance and their change (approach speed) detects the lateral movement of the image must be, and relatively to the one corresponding to the direction of travel "optical axis".

As a result, it is necessary to look in the direction of travel by means of a aligned lens in an image plane to design an image, its proportions wander across the image field according to the angular velocity. Objects that are at Drive straight ahead, lie exactly in the direction of travel and do not make any movements of their own. have no angular movement. In relation to the image field, this means that in Direction of the optical axis a point without lateral relative movements exists. The greater the angle of the image-generating rays to the direction of travel, the greater At a given distance and relative speed, the angular speed increases and thus the speed1 with which the pixels move across the image field.

If, as shown in FIG then apart (or together) with the same and opposite speed, if there is no lateral movement: For a given distance and approach speed, v or ve increases with x due to the above-described dependency of the angular speed on the angle between the direction of travel and the direction of view. If, for example, one were to attach an image speedometer measuring in the x-direction at a distance x to the left and right of the bisector, then the approximation speed could be determined from the size and sign of the image point displacement speeds measured there by arithmetic mean value formation (sum signal) and the lateral velocity could be determined by formation of the difference.

If, for energetic reasons, one wants to use a large-area image speed meter in each of the image halves, the dependence of the values on z interferes, but only as long as linearly divided spatial frequency filters are used for this purpose in, for example, optical correlators. If one uses e.g. a sinusoidal non-linear periodic division, one can obtain signals of the same type for a certain approach speed over large value ranges of x.

If you halve the image instead of two x halves, you also halve it into two y halves by a second straight line that runs horizontally through the "rest point", then applies analogously the same as already described. In fact, the pixels run radially "Resting point" away.

As a result, circular arcs are suitable for the task described non-linear divisions similar to a Fresnel zone plate or sections thereof optimal as a spatial frequency filter (Fig. 2g).

In land vehicles there is generally only sideways movement, i. E. Displacement in one dimension in question.

Therefore, two image speed sensors are sufficient in the image field. Naturally it is also possible for other applications to use corresponding sensors for the second Insert coordinate and from four sensor signals also the direction of one Determine transverse movement in four quadrants.

In FIG. 3 is a structure designed on the basis of the above considerations for a passive anti-collision device shown schematically. As can be seen a speed correlation system 1 '' 'measuring according to four quadrants is provided, their output signals assigned to a coordinate direction each to a summing stage 34 be 341 and a difference generator 33 or 352 are supplied. The outputs of these stages become a. Verbältnisbildner 36 supplied to the in each case the sum and the difference of the signals associated with a coordinate direction relates to each other.

An arithmetic unit 37 is connected downstream of it. The lorrelatorsystem is a distance measuring system 38 assigned whose output signals are also in the Arithmetic unit 37 can be entered. The output signals of the arithmetic unit can be like indicated, are evaluated in different ways.

once it is possible to create a servo system with these output signals 39 to feed, which slows down the speed of one's own vehicle for so long until the vehicle's own speed is less than or equal to that of the other vehicle. Acts The appropriate object, on the other hand, is an immovable object, so your own vehicle is braked. In addition to such a servo system is a display device 40 and / or a warning device 41 can be provided by which the emerging danger is clearly represented It is beneficial to the to mount both measuring systems 1 '' 'and 38 behind the windshield of the vehicle, where they are protected from the elements.

The advantage over the new passive anti-collision device What is known is that obstacles are on a collision course with other obstacles (e.g. roadside) can be clearly distinguished because they are in the measuring system do not generate an asymmetrical signal component.

By using photoelectric responsive to IR rays It is also possible for receivers to receive signals from a vehicle in front to be received when there is no daylight and the reverse lighting for the vehicle in front has failed.

It is advantageous to provide two optical correlator systems on the vehicle, one of which measures in two coordinate directions and the front end of the Vehicle is assigned, while the other, only measuring transversely to the direction of travel Correlator system is assigned to the rear end of the vehicle. This arrangement is necessary for the early detection of the breaking away of the rear of the vehicle.

As has been shown, the signal quality of the correlator system thereby further improving1 by the respective object structures, which preferably contribute to signal generation and have large spatial frequency components in the measuring direction, This is preferred over other object structures in terms of their image sharpness can be achieved, for example, by entering the beam path of the correlator system, preferably in the aperture area or in a confocal area of its imaging area Optics, a slit diaphragm or, in the case of two-coordinate measurement, a cross-slit diaphragm arranged such that the longitudinal axis of each slot is perpendicular to a direction of measurement of the grid is. It has been shown that by using such a slit diaphragm Signal improvements by a factor of 3 and more are possible.

Claims (9)

Claims 1. Method of measuring, regulating and / or displaying the movement of Land vehicles over preferably unmarked surroundings, especially according to patent ... (Patent application P 22 15 576.6-52), characterized in that for the purpose of ongoing distance measurement between the vehicle and one on the road Obstacle using at least one optical, one grid (25) in one Image plane and at least one assigned to this grid that scans the grid photoelectric receiver (28, 29, 30, 31) having, as well as mechanical Movement of an optical component or by polarizing or splitting according to scars optical components a correlator system generating signals containing orientation information (1'2) an image structure of the obstacle is detected and from the amplitudes of the Output signals of the correlator system provide information about the distance or its Change is gained after comparing it with the speed of your own Vehicle above ground at least one display and / or warning device (4c, 41) is fed. 2. The method according to claim 1, characterized in that for the purpose of detecting an obstacle in the direction of travel, the correlator system (1't ') is directed forward, from the frequency and phase position of its output signals in addition to the relative speed across the direction of travel between the vehicle and a signal proportional to the obstacle is obtained, which signal is then used to influence a servo system (39) which influences the speed of the own vehicle. having a correlator system an image structure of the following vehicle is detected and the approximation speed as well as the distance to be followed Vehicle proportional signals are generated that after comparing it with the speed of your own Vehicle assigned to a display and / or warning device 3. Device for carrying out the method according to claim t, characterized in that that one aligned in the direction of travel, preferably for measurement in two coordinate directions suitable optical, at least one grating (25) in an image plane and at least a photoelectric receiver assigned to this grating and scanning the grating (28, 29,30, 31) exhibiting, as well as by mechanical movement of an optical Components or by polarizing or color-splitting optical components Correlator system (1.11) generating signals containing directional information proceeded, its taking advantage of the object perspective and changing it The electrical output signals obtained are always perpendicular to the direction of view Coordinate directions are fed to a downstream comparison stage that this comparison stage a summing stage (34, 34t), a difference @ stage (35, 331) and / or ratio-forming stage (36) and that this comparison stage comprises a Arithmetic unit (37) is connected downstream, which additionally consists of a distance measuring system (38) originating signals are fed, and that at the output of the R * ohenwerke (37) a servo system (39) and / or odor influencing the driving speed of the vehicle a display and / or warning system (40, 41) is connected. 4. Device for performing the method according to claim 1, characterized characterized in that an optical, at least one grid in an image plane or at least one assigned to this grid, Correlator system comprising the photoelectric receiver scanning the grating is provided whose electrical output signals together with the speed the own vehicle proportional electrical signals from a comparison device are supplied, which is followed by a warning device 5. Establishment according to claim 3 or 4, characterized in that the correlator system in the vehicle is arranged behind the windshield or the rear window. 6. Device according to one of claims 3 or 4, characterized in that that the grid of the correlator system is preceded by a polarizing splitter. 7. Device according to one of claims 3 or 4, characterized in that that the grid of the correlator system is assigned a mechanical drive (ins). 8. Device according to claim 3 or 4, characterized in that the optical system in terms of its imaging performance and / or energy transmission Has optically effective components optimizing in a defined measuring direction. 9. Device according to claim 8, characterized in that the gakena optically effective optimizing component a slit diaphragm or a cross-slit diaphragm iat in the aperture area or in a confocal area of the imaging optics.