publication number DE102009028261 (A1)
Release date: 2011-02-10
Inventor: Niemz VOLKER [DE] + (Niemz, VOLKER)
Applicant: BOSCH GMBH ROBERT [DE] + (ROBERT BOSCH GMBH)
Classification:
International: B60W30/06; G08G1/16
European: B62D15/02H6
Application number: 20,090,805 DE200910028261
Priority number (s): DE200910028261 20,090,805
The EPA is not responsible for the accuracy of data originating from other authorities than the EPO, and thus in particular not liable for its completeness, timeliness or fitness for a particular purpose. Information, please refer to the respective patent authorities.
translate this text description of DE 102009028261 (A1)
Stand art
[0001] The invention relates to (semi-) automatic parking assistant that support the parking in a parking space with automatic steering.
[0002] parking system have sensors to detect a parking space when driving past, and to the subsequent parking in reverse gear as optimal as possible retract into the parking space. Here, the steering wheel is performed automatically, while the reverse driving an actuator operates the steering wheel, wherein the actuator is connected to a controller that calculates the optimum steering angle and providing for the parking trajectory.
[0003] According to the state of the art is assumed that the predetermined parking path, that is the target parking trajectory and therefore the (current) Einlenkwinkel of the actuator and the steering gear is a high accuracy. This is the art, for example, achieved by the appropriate steering components are sized according to the load and provides a high torque steering compliance with the driving requirement. Similarly, it is known impaired maximum Einlenkwinkel to use a safety margin to actually provide Einlenkwinkel possible, so that it can be of a precise implementation assumed independent of Einlenkwinkelbetrag.
[0004] According to the invention it was recognized that such a control method in which expected Is that the default will be implemented accurately, for example, can be affected by aging processes or use with respect to their interpretation is not in full.
[0005] It is therefore an object of the invention, a method and control necessary to provide parking assistance can be used to trigger precise. In particular, it is an object of the invention to provide a precise parking aid, even if the affected systems subjected to a mechanical failure.
disclosure of the invention
[0006] The invention is achieved by the method and the control according to the independent claims.
[0007] the invention underlying concept is to Einlenkwinkel not by a control procedures should be considered in which it is intended that a target is met exactly, but by a control procedure should be one can take into account when driving errors that occur, so that the error is at least partially is compensated. In particular, can thus provide parking system in which a strong deviation from a more or less strong steering error, which is even with faulty systems, a precise steering of the vehicle when parking possible. For this purpose, the method provides a nominal charge for parking path (which is calculated in the prior art and also in the art to directly control an actuator is used), and an actual trajectory capture to detect by comparing a mistake, which is compensated according to the invention. The compensation can be provided by correcting the Ansteuervorgaben supplied by the actuator, or by calibration, for example according to a corrected actuation curve.
[0008] Unlike the prior art is not expected that the target parking trajectory of the system is running as planned, but it is used for control and eventual control an actual trajectory recorded so as to perform comparisons. This is the actual trajectory with the target trajectory compared in order to determine an error. This error is again in the application used for corrective measures, especially when creating a correction parameter (which can numerically the error substantially correspond directly or indirectly), the Einlenkwinkel that the control is passed, according to a combination of the set angle and the correction parameter (which reflects the error) is provided. As correction parameters, a characteristic actuation is called, according to the detected errors will be created. In contrast to the prior art, in which the target Einlenkwinkel corresponds exactly to the parking path-and it is assumed that the system should be leaving the parking trajectory-precisely, is the invention according to the steering system according to a combination of this (target) setup and controlled by the correction parameters. The consideration of a pre-recorded correction parameter or the light of the perceived error between actual and desired trajectory allows precise parking according to the desired parking path even with faulty steering systems, since their activation is accompanied by using the correction parameter with an error compensation.
[0009] The consideration of the correction parameter, which reflects the detected error can be described and provided as a regulatory as well as calibration, the calibration is that the controlling system should remain with the railway history is driven, but this trajectory according executes the correction parameters and the corresponding actuator passes. The correction of such a control system corresponds to a calibration, the calibration according to the invention is the comparison of a train set with a course-based web course. The inventive system approach is provided here by the fact that an error between target-trajectory and actual trajectory is detected and is taken into account this error in the controller. The inventive system differs from the novel calibration although the fact that the error is in the regulation continuously recorded during the control, and in the calibration of the first error is detected to be used for future control processes, However, both aspects of the inventive concept is implemented, therefore, an error between desired and actual trajectory is detected and is considered during parking operation of these errors in the control. Because the invention relate to the concept of calibration and the concept of control, the same concept, namely the correction of an error between actual and desired course and take account of this error in the control. Therefore, in addition, the term calibration is not distinguished from the term scheme, unless otherwise indicated.
[0010] The inventive method for calibrating a parking aid, therefore, relates to a parking assistance, for active control of a Einlenkwinkels a vehicle is set up. As an active control in particular electro-mechanical actuators are known which are connected to the steering system of a vehicle. As a particular vehicle, vehicles, for example, refers to persons or heavy goods vehicles for which an axis (or both axes) are schränkbar to determine the direction of the vehicle by steering. The actuators also electro-hydraulic or electro-pneumatic power converters are suitable. The controller is preferably provided electronically, but in principle, pneumatic or hydraulic controls are possible. In the latter implementation options, however, must be provided converter to electrical sensor signals into corresponding convert physical print sizes.
[0011] The inventive method provides cover a parking space automatically by sensors, that is, by driving past the parking space, the sensors are preferably directed to the side of the vehicle to detect other (parked) vehicles or the obstacles. The sensors can, for example, ultrasonic or radar sensors.
[0012] is also a target trajectory calculated using the so-covered parking space. This calculation also includes a history of Einlenkwinkels along the path to be traveled. The trajectory can be approximated by straight lines, segments of circles and spirals, with the individual sections trajectory of a particular course of Einlenkwinkels match. In particular corresponds to the trajectory of the integral of the curve of the Einlenkwinkels. For example, segments of circles result from a constant Einlenkwinkel, the amount is not zero, straight lines result from a constant Einlenkwinkel from zero and spirals result from linear increase or decrease in the linear Einlenkwinkels along the trajectory. Based on the geometric data of the parking space (in particular its length and the location of the front end) can be such a target trajectory are created, which is divided into sections, which have a specific Einlenkwinkel or a particular course of Einlenkwinkels compare (for example, linear Increase or decrease equivalent).
[0013] The invention also envisages to provide the resulting course of the Einlenkwinkels or the target-trajectory obtained by controlling a controllable actuator. The controllable actuator is, for example as described above electromechanical actuator, digital or analog signals received that reflect the desired to be controlled Einlenkwinkel, wherein the actuator a corresponding movement, a corresponding torque or a corresponding force generated to the steering system of the vehicle provided according Einlenkwinkel operate.
[0014] The method further comprises the steps of sensing of an actual trajectory, which is in accordance with the tax Desired trajectory or according anzusteuerndem Einlenkwinkel results. The actual trajectory can be provided by a whole with geometric data shown trajectory can be divided, in which has to be controlled Einlenkwinkel a certain well-defined process (for example, sections with a constant angle in sections with a constant angle equal to zero or with linearly increasing / falling angle). The actual trajectory can also be detected by the detection of the actual, in the steering system of the vehicle Einlenkwinkels ruling, as it is with the-track course is clearly linked. As the actual trajectory may also include a direction or an actual Einlenkwinkel be provided, the maximum, to be controlled Einlenkwinkel equivalent. Furthermore, the-track course is covered by repeatedly detecting a lateral distance after the vehicle is driven into the parking space. However, preference is to capture the actual trajectory provided by detecting the maximum in the steering system of the vehicle present Einlenkwinkels, this corresponds to a maximum, driven Einlenkwinkel.
[0015] According to the invention of the actual trajectory (which may be provided only as an angle specification) with the desired trajectory (which may be provided only as a default Einlenkwinkel) are compared, and which is from the comparison resulting error determined. The comparison can be provided as a difference between a device to be controlled Einlenkwinkel and that actually present in the steering system Einlenkwinkel (target-comparison), with the error corresponds to the difference. The error is particularly provided as a value that corresponds to the resulting difference value.
[0016] Further, a correction parameter is created that is identified in a particularly simple embodiment the error. In general, the correction parameters generated by a monotone function is associated with the error. If thus the amount of the error, so does the correction parameters (or the amount). The monotonic function can be a monotone or strictly monotone function, such as a linear or directly proportional function, the function is a monotone can be monotonically increasing or a monotonically decreasing function. The function is chosen as increasing or decreasing function, depending on how the resulting correction parameters will be considered for control. However, according to the invention should be given that the combination of the set angle with the correction parameters and the creation of the correction parameter to an at least partial compensation of the error in the controller.
[0017] The Einlenkwinkel according to the inventive method is combined with the correction parameters, for example by adding (or subtracting, depending on whether the function is rising or falling), whereby the actuation of this combination equivalent. The control is based not only on a given angle, but also on an order from the control of the actuator to be combined correction parameter, which reflects the reaction between anzusteuerndem angle and angle actually produced.
[0018] According to a first aspect of the invention, the actual trajectory detected by detecting an actual angle adjustment from the position of a steering wheel, a steering linkage, the actuator or other component of the steering system. The actual opening angle can be detected by a particular angle sensor that is connected to the corresponding component. The direct recording of the adjustment angle can also be made by evaluating a Trajectory. If according to this aspect of the invention, the actual trajectory of the actual opening angle covered, so there is a relatively simple calculation because of the actual opening angle is only a single numerical date, which accordingly requires a low computational effort. In principle, the angular position detected by an angle sensor or angle sensor at each point of the steering system that moves the steering.
[0019] According to a second aspect of the invention, the-track course is recognized not only by a single angle information but on the basis of an entire locus, preferably in the form of a locus, which reflects the movement of the vehicle. The locus may also include the movement of the vehicle part or represent the movement of a sensor or a sensor device that is attached to the vehicle. In principle, the trajectory can be measured by any vehicle component that is connected to the vehicle. In addition, the-trajectory is detected by repeated, continuous or amortized acquisition sensor, the sensor detects the distance, or preferably, a relative position of the vehicle to an outside object.
[0020] According to another embodiment of the invention consists of controlling the Einlenkwinkels driving the actuator with a desired Maximaleinlenkwert. The recording current trajectory comprising: detecting an actual Maximaleinlenkwerts, who by driving with the set-Maximaleinlenkwert results. According to this embodiment, a target Maximaleinlenkwert given, and it is by means of a-Maximaleinlenkwerts determines whether the steering to the target followed by complete or accurate Maximaleinlenkwert implement, or whether a lesser Maximaleinlenkwert actual results, as the proposed Maximaleinlenkwert, the by controlling the target Maximaleinlenkwerts would result in a perfect system. Thus, a target Maximaleinlenkwert as a target entry point used, by comparison with actual construction Maximaleinlenkwert actual results, whether the system to the target Maximaleinlenkwert completely or whether the system follows the set-Maximaleinlenkwert not follow due to errors can. The error is due to the difference between desired and actual Maximaleinlenkwert Maximaleinlenkwert. The difference is charged preferably with a sign that takes into account the steering direction. In particular, the difference may be formed by the difference between the amount of the target Maximaleinlenkwerts and the amount of actual Maximaleinlenkwerts.
[0021] In the foregoing embodiment, the error is determined by specifying a maximum Einlenkwerts and observing the reaction through the steering system. The actual Maximaleinlenkwert here can be detected by determining the position of the steering wheel, steering linkage, the actuator or other component of the steering system of the vehicle. Here rests the When determining the actual, implemented-Maximaleinlenkwerts on the detection of an angle by means of an angle sensor. As an alternative of the actual Maximaleinlenkwert also be determined on the basis of the maximum curvature of the recorded actual trajectory. Here, the maximum curvature of a portion of the identified locus, with this section is a result of set Maximaleinlenkwerts results. This ensures that the maximum curvature within this section should be the result of control by the maximum value is. The locus corresponds to the actual trajectory, which reflects the movement of the vehicle. The actual trajectory is thus the locus of a component that is attached to the vehicle such as a sensor, is detected by the the parking space. In the latter method is thus the actual Maximaleinlenkwert determined by observing the movement profile of the vehicle.
[0022] According to another embodiment of the invention, in particular, can be combined with the above embodiments, based on Maximaleinlenkwerten, runs a first Einparkschritt according to experience, and directly or indirectly, then following a second Einparkschritt and peak at two Einparkschritten different Einlenkwinkel be used. The maximum Einlenkwinkel is on the second Einparkschritt (in general: the control variable) is greater than the first Einparkschritt so as to gradually to determine the limits of the steering system. The boundaries of the steering system here called control parameters, which leads an increase in displacement to significant errors. This is for instance the case where a permanent border, such as the Auslenkgrenze, a maximum angle of the actuator or a maximum torque of the actuator is achieved. At this point begins a range of oversteer, which manifests itself in the fact that a further additional increase of the drive signal is fully implemented. This is for instance the case with high steering angles to develop in which the tires too much drag as the actuator of the tires under control may give in on. Other sources of error include steering play or friction within the steering system with strong fluctuations, with the increment or increase between two Einparkschritten is used to detect the critical point at which the angle control is faulty. Therefore, the method includes performing a second Einparkschritts by driving with a maximum Einlenkwinkel which is increased compared to the first actuation Einparkschritt an increment. Here, the maximum and actual windings of each-resulting trajectory is compared to detect whether the actuation increment is fully or only partially implemented by the steering system. It is detected that the increase in the actuation increment insufficiently in an additional actual steering angle is implemented, then this angle is preferably stored and future desired trajectories are such that they have a maximum curvature that are not covered above is the maximum curvature (or the applicable Einlenkwinkel) content. According to the invention are stored maximum Einlenkwinkel such scheduled to be considered in the following Einparkschritten can. The described embodiment is based on provoking an error in which the maximum Einlenkwinkel is increased to a lack of precision limit up to which the system can follow the given angle, strong but after the maximum Einlenkwinkel Inaccuracies generated. The correction parameter is then in a value that provides a cap so that the following set-tracks extending Einlenkwinkel no greater than the maximum Einlenkwinkel thus obtained is used. This cap can be used for creation / modification of a control curve.
[0023] The actuation increment is increased with each increasing Einparkschritt, and the actual at each Einparkschritt resulting maximum curvature is measured in concrete terms. The curvatures of the respective maximum-Einparkschritte is compared. In particular, this is the increase of the associated maximum-curvature is recorded following successive Einparkschritte. The correction parameters is then obtained by detecting a reduction or absence of the increase in the comparison of actual maximum curvature of successive steps. For example, if the maximum Einlenkwinkel increases by an activation-increment, then a reduction or absence can be seen in a flattening of the increase over the actual increase in the maximum curvature. The correction parameters are then a cap of the driveable Einlenkwinkels. This corresponds to a calibration, which target parking trajectories generated thereafter, calibrated, and thus have no maximum curvature, which is equal to or greater than the maximum actual curvature.
[0024] Instead of the boundary of a fault-free grasp control by the maximum Einlenkwinkel Park is recognized for consecutive steps, the Einlenkwinkel be increased gradually during a single Einparkschritts. Here, at the same time, the resulting-track course is detected (either by detecting the locus along which the vehicle moves, or by determining the position of the steering wheel, steering linkage, the actuator or other steering system components), and the corresponding (current) controlled Einlenkwinkel (according to the desired trajectory) is detected. If there is a situation that is indeed the Einlenkwinkel still elevated, but the actual trajectory and the position of the steering system component that increasing Einlenkwinkel not (completely), it follows, then the controlled Einlenkwinkel or the position of the steering wheel can be determined from which an increase in Einlenkwinkels not the desired increase in the position of the steering wheel with the result. Here, the curvature continuously or gradually in particular, that is incrementally increased. The increase in the curvature of the resulting actual trajectory and the increase of the angular position of a longitudinal system component is detected and by comparison shows that the system currently in an error-free control area is working or has worked in a flawed taxation. In this context, increasing curvature and increasing Einlenkwinkel increasing Strength of the comply, regardless of the sign. or Einlenkrichtung, so that these terms are equivalent to the amount of curvature or the amount of Einlenkwinkels. Therefore recognized the Einlenkwinkel in which the increase in the curvature (of the amount of curvature) of the actual trajectory and the position of the longitudinal system component is less than the increase of the curvature of the desired trajectory, or less than the increase of the controlled Einlenkwinkels. The correction parameter is then provided with a value that corresponds to this curve and this position or the corresponding Einlenkwinkel, the correction parameter to a value equal to the lesser Einlenkwinkel gain. Here is the detection of the smaller increase (of the Einlenkwinkels) is equivalent to the coverage of an area, working in the tax system no longer linear or faulty the target trajectory to be controlled or the Einlenkwinkel implement. The corresponding correction parameters will be saved and to as the cap for the desired trajectory provided so that in a further Einparkschritt controlling the Einlenkwinkels under this cap does not go beyond this. In particular, the set path of development of the following steps Park provided such that its maximum curvature (in magnitude) is not greater than this ceiling.
[0025] To detect whether a growing Einlenkwinkel the resulting Actual trajectory followed, a (given) threshold are provided, which is compared with the amount of deviation and leads only above a predetermined amount of error or difference threshold for detecting the correction parameter. This can be realized by means of a comparator and a predetermined threshold, the comparator the threshold with the difference between desired and actual amount compares and exceeds the threshold value, the inventive system prompted the related Einlenkwinkel or associated desired curvature to . save This value corresponds to a stored calibration value that is used for the following parking maneuver to avoid that to be controlled Einlenkwinkel in a range in which the control is faulty.
[0026] The thus-described method thus control calibrated according to a standard interval in which to be controlled Einlenkwinkel are admissible and lead to a limit as to the amounts of Einlenkwinkels to a faulty implementation. Instead or in combination with this, a linear error can be captured and used for calibration, said to be controlled Einlenkwinkel is increased and the associated implementation by capturing the actual trajectory as described above is compared with this. How to recognize that the implementation is not provided complete and that the actual increase is set by the angle-angle increase different, then the ratio of nominal and actual angular increase can be formed. This ratio is used for calibration of control systems and other Einparkschritten, for example, the Einlenkwinkel to be controlled by the inverse of the ratio to be multiplied before the adjusted Einlenkwinkel is used for driving. This error can be compensated, the linear or proportional increase with Einlenkwinkel.
[0027] The invention is further achieved by a controller that is used to execute the method described above. The controller includes an input for detecting physical environment characteristics (to capture the parking space) and for detecting the actual trajectory and the change in direction, which results from the control. The controller also includes an output to drive an actuator to be controlled according to the Einlenkwinkel. A calculation of the control unit is connected to the input and the output is connected and calculates the desired trajectory based on the environmental features. Furthermore, this calculation takes into account the correction unit parameters in which the desired trajectory for example, provided with a maximum curvature, which is under a Einlenkwinkel after which the train follows the course of defective only driven Einlenkwinkel. The controller also includes a comparator to detect this error. In particular, the comparator is set up, the actual trajectory with the desired trajectory to compare, the comparator can also identify any error. The controller also includes a correction installations such performing the above into account the correction parameter. The correction device is configured to create the correct parameters as a function of the error, and is set up, the target parking path, the to be controlled Einlenkwinkel or both correct. Here, the combined correction means the target trajectory and the Einlenkwinkel adjusted by the correction parameters. According to a particularly preferred embodiment, the combination, which is provided by the correction device, the lid of a target to be created according to trajectory the maximum Einlenkwinkel from which the steering system should be the only faulty specifications follows.
[0028] To detect the train or the course is Einlenkwinkels also includes the control of an angle sensor that can be connected to a mechanical steering system component. This steering system component can be provided as a steering wheel, steering linkage or as an actuator that actuates the steering. The angle sensor detects the angular position of each vehicle component, which may be the chassis of the vehicle, the angle sensor is also connected to the input in order to make this angle signals that represent the detected angle.
[0029] To capture the maximum possible curvature or the maximum possible Einlenkwinkels also includes the control of an incrementing to increase one increment or the actuation to be controlled Einlenkwinkel, preferably in a progressive step at a constant height. The associated, resulting maximum curvature of the resulting actual trajectory is detected and evaluated. The controller evaluates indicate whether the increase in the actuation increment to a maximum curvature of the actual trajectory leads. The controller detects whether the increase in the actuation of the increment increase in the curvature of the actual trajectory requirements, or whether the increase of the actuation increment less than the maximum curvature of the actual trajectory is. Here, the control unit detects whether increasing the actuation increment to a maximum curvature of the actual trajectory leads, which is less than a predefined threshold value compared to a maximum curvature that resulted from the increase in the Ansteuerinkrements increased. In other words, by the controller using a predefined threshold, the deviation between desired and actual angle covered by increasing the actuation-increment. A comparator compares the threshold with the difference between the respective increases in the setpoint and the actual value. Exceeding the threshold here means that the actual angle can not get the desired angle and thus follows the control in a range, in which the desired non-default error-free implemented. If the threshold is exceeded, the controlled Einlenkwinkel or curvature of the actual trajectory is stored as a calibration basis. When considering further driving or parking maneuver by restricting the system to be set Einlenkwinkel or the curvature of the desired trajectory according to the stored calibration base capped to ensure that the system as the parking goes into an area where the actual angle no longer complete the desired angle follows. The calibration base can be stored in a memory of the system, with the restrictions of the system is connected to this memory to the creation of the desired trajectory or taken into account in the management of those to be Einlenkwinkels calibration.
[0030] The inventive device can be implemented using a microcontroller to implement its software and related software components, with the software or the software elements of one or more components of the control. Instead of or in combination with a programmable processor can also be used Quiet circuits whose function is predetermined by your circuit. In particular, the comparator can be provided by a hardware comparator. The input and output can be provided either as digital as well as analog signal interface, wherein in use of analog signals of the input and the output preferably includes a D or a D / A converter.
[0031] In a preferred embodiment of the apparatus and method may first target for several consecutive Einparkprozesse for each successive Einparkprozess the maximum-Einlenkwinkel be increased by one increment until the maximum possible Einlenkwinkel is collected from the steering system is not longer or only faulty Einlenkwinkel follows the target. In the following, then the inventive calibration is used as a surveillance measure that engages in the appropriate control. After this maximum Einlenkwinkel recorded, this considered in the following Einparkprozessen is (set by creating underground pathways with a maximum curvature which does not exceed the maximum possible Einlenkwinkel) according to the invention, the execution of the desired trajectory in other Einparkprozessen be monitored by detecting the desired trajectory with the actual trajectory to be taken into account to determine new to errors occurring during the further Einparkprozesse Einparkwinkel the maximum possible (as described above) for this then for even following Einparkprozesse as described above. For both processes the same sensors (sensor distance, angle encoders) are used. In addition, the process for determining the maximum possible Einlenkwinkels be repeated in order to be able to change the Strassen-/Reifenbedingungen into account. Thus, for example process for determining the maximum possible Einlenkwinkels repeated either periodically (in particular for every n-th Einparkprozess example with n = 20, 50 or 100) or the process is in detected changes repeated on the chassis, for example, after inspection and / or when new tires were reared, or both. With proper calibration, the maximum possible re Einlenkwinkel reassessed and may be less than the previous maximum Einlenkwinkel be, bsp. if friction forces have increased in the steering system, or may be greater than the previous maximum Einlenkwinkel be if friction forces were reduced, as is the case where a change of winter tires was run on summer tires. The inventive control system for this purpose has an input with the inspections and tire changes can be detected, bsp. an interface for user input.
short description of the figures
[0032] The 1a, 1b, an exemplary situation shows a novel maneuver, where the impact is 1b, the corresponding angle.
[0033] The 1a and 1b together show the exemplary situation on the basis of designated as 1a half above the dotted line and reference the unit designated as 1b half below the dotted line.
[0034] 2 shows an embodiment of the novel controller for executing the inventive method.
Detailed Description of the figures
[0035] The 1a illustrates a vehicle in a first position 10 and a second position 10 ', the vehicle with the reference number 10 after driving past a parking space backwards einparkt in this and in the position 10' remains. The parking space extends between the vehicles 20, 22, in which is shown in broken lines and between which the parking space for the vehicle 10 arranged '. The inventive parking aid controls the steering operation, so that the reverse parking, a target trajectory is 30, which is also the equal-track course. Consider the motion of a point 12, 12 'of the vehicle 10, 10' is diverted at a distance of 40 on the vehicle 22nd This point 12, 12 'of the vehicle 10, 10' is located inside the vehicle, so that r is a vehicle edge a minimum distance results. The distance refers to the critical point of the vehicle 22, which means the gap facing the parking area, which is also the vehicle 10, 10 facing '.
[0036] The target-track course includes a first section 40 in which the vehicle is traveling straight ahead parallel to vehicle 22 to the left. It includes A second section 42, which increases the Einlenkwinkel [phi] of the vehicle linear, resulting in an increase in curvature results. In a third section 44 reduces the Einlenkwinkel linear up to a Einlenkwinkel [phi] of zero. At the left end of the section 44 is thus a selective Einlenkwinkel [phi] from zero, at which the target or actual trajectory, at least for now the long axis of the vehicle in the current position corresponds. The portion 44 is adjoined by a section 46 in which the Einlenkwinkel [phi] is increasingly raised until a. Maximum is reached. It joins a fifth section 48 of that in which the orientation of the vehicle parallel to the original orientation is where the Einlenkwinkel [phi] is continuously (ie linearly) reduced to zero.
[0037] In the 1b is an example of Einlenkwinkel [phi] with a solid line shows where the individual y-sections 40 - 48 relate to the particular location of the vehicle with the 1a. The solid line 50 corresponds to the course of Einlenkwinkels for an ideal system that requires no inventive calibration.
[0038] As already noted are real systems, however, subject to a maximum Einlenkwinkel that is described in 1b, 60, 60 '. From this angle supports the actuator based steering system will not set the course or the train to be controlled Einlenkwinkel, but the amount the curvature is no longer increasing with increasing amount of curvature of the target-trajectory. The resulting cap is shown in the dotted line 1b, and as of the Maximaleinlenkwert 60, 60 ', the steering system should increase despite the preset does not follow completely. According to the invention is determined the error 70, between the set and actual specification of the Einlenkwinkels is to provide the correction parameters to be set as a cap on the Einlenkwinkels. For future calculations of the desired trajectory of the cap is taken into account, which result from the limits 60, 60 ', with an adjusted target trajectory can result in 80th The dashed lines according to correction parameters corrected desired trajectory 80 takes into account the lower maximum Einlenkwert (60 ') to see where is that Einlenkphase in the corrected set path curve 80 before be begins to ensure despite lower Maximaleinlenkwerts that the vehicle is not moved laterally to the vehicles 20 to 22 are comes, and thus the vehicle is not designed optimally in the parking lot. And outlined in 1b corrected desired trajectory has a similar shape as the uncorrected curve 50th In particular, both curves is no section in which a Einlenkwinkel is maintained equal to zero. However, an enabling customized set path over a shape other than an intended trajectory without correction should have such by the activated upon reaching the Einlenkwinkel Maximaleinlenkwerts remains constant, resulting in a trapezoidal course of Einlenkwinkels [phi].
[0039] According to the invention to be controlled Einlenkwinkel is increased gradually, see curve 52, wherein the increments are the same. The width of the step to be controlled Einlenkwinkels of course 152 is shown enlarged to better illustrate the invention. It is seen that in the first iteration 52a and 52b of the second iteration to be controlled Einlenkwinkel is fully implemented, as the Maximaleinlenkwert 60 is not 'reach. While the increment is, however, results in an error between 152c adjusted Einlenkwinkel the course 152 and the threshold exceeded actual Maximaleinlenkwert, shown with a dotted line. This error between the adjusted Einlenkwinkel iteration is 52c is compared with the 60-Maximaleinlenkwert '(which is also present during the increment is 52 c-Einlenkwert is equivalent), the error is relatively small, as in the example shown in 1b the increment is to be set Einlenkwinkel 52c just above the actual Maximaleinlenkwert is (dotted line), which is also the Einlenkwert-equivalent. The error value is less than one error threshold, so that when comparing the two values is still no comparison result signal corresponding to the occurrence corresponds to an error. As the following increment is 52 d but at a to be controlled Einlenkwinkel out, which is well above the Maximaleinlenkwert, there is an error 70 which is well above the allowable error. The comparison with the error threshold leads therefore to detect the occurrence of an error at this desired angle. In comparison with the increment is 52c is therefore clear that during the 52c was the increment is to be set Einlenkwinkel within different parameters and the increment is 52 d to be set too high a Einlenkwinkel (ie, target angle) resulted. Therefore, the increment is to be set Einlenkwinkel of 52c according to the method saved as a cap, which reflects the correction parameters. In the following Einparkverfahren then stored correction value equal to the Einlenkwinkels is not exceeded 52c. The same is true during the same Einparkprozesses, so that at step 52d, which leads to an undesirably high error value, to be controlled Einlenkwinkel is automatically reduced to the value of the increment is 52c. At the same time this is, in setting the desired trajectory considered in order to park the vehicle as desired, without operate the steering system in a region that is associated with excessive errors, which in turn is undesirable misalignment of the vehicle to park would result.
[0040] The 2 an inventive control shows the overview block diagram. The system 2 includes a steering system 100 of a vehicle (not shown), the mechanical steering system 100 is operated by an actuator 110 mechanically. This actuator 110 corresponds to an electromechanical transducer that is controlled by a control unit 120 electrically. The control unit 120 receives signals from a computing unit 130, the desired one-track course pretending. The desired trajectory is reflected by means of parking assist sensors 132 that are arranged as distance sensors to an outer side of the vehicle. Alternatively, a vehicle camera and an image processing device for Parking space detection are used. The steering system 100 is coupled to a sensor 140, which is the Einlenkwinkel-recorded and passed on to the one expensive unit 120, in particular to the comparator 122 of one expensive unit to 120th The comparator 122 of the control unit 120 receives also a target Einlenkwinkel (as a result of the calculated nominal trajectory), that is the Einlenkwinkel to be controlled, via a connection 134 that connects the control unit 120 with the calculation unit 130. The comparator 122 compares the desired target, which is supplied by the connection control unit 134 of the 120 recorded, with the sensor data of sensor 140 in order to be controlled if the Einlenkwinkel not fully realized and is thus the actual Einlenkwinkel is less than the Einlenkwinkel to be controlled. The difference will be detected by the comparator 122 and error. When the error reaches a threshold value, then the corresponding actual Einlenkwinkel (which is provided by the sensor 140) is stored in the correction parameter memory 150th The correction parameters memory 150 then stores the actual-Einlenkwinkel, after which no accurate control is possible. According to a preferred embodiment, the memory 150 also stores the size of the associated error. To the error that is provided by the comparator 122 to compare with a maximum permissible error, the control unit 120 also includes a threshold 124, of a maximum permissible error of an error memory 126 is replaced. The comparator 122 is in accordance with a preferred embodiment, the broken line in 2 is shown to take into account the error and in particular the associated Einlenkwinkel to the calculation unit 130 further (see dashed connection), so you want the calculation unit 130 the Maximaleinlenkwert at the next calculation of railway history can.
processes and controls for the calibration of an automatic parking assistant directing
Technical and scientific translations
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