PROCEDURE FOR TREATMENT OF OBSTACLES IN AN INTERNAL TRANSPORT TROLLEY
Patent Information
- Application Number
- IT502026000034609
- Authority / Receiving Office
- IT · IT
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-05-16
- Publication Date
- 2026-07-22
- Estimated Expiration
- 2043-05-16
AI Technical Summary
Current obstacle detection systems in industrial trucks often trigger false positives during controlled maneuvers, leading to unnecessary braking and reduced performance, as they fail to differentiate between safe and unsafe driving situations, particularly during cornering or entering aisles.
The method involves detecting current speed and steering angle, calculating a protection zone, evaluating sensor data within this zone, and determining steering angle differences to avoid obstacles, while suppressing measures if the operator can safely steer around them, and only triggering interventions in critical situations.
This approach reduces false positive hazard detections, minimizing disruptions to operators and ensuring collision avoidance only in actual dangerous situations, thereby enhancing operational efficiency and safety.
Abstract
Description
[0001] The present invention relates to a method for obstacle handling in an industrial truck, which comprises at least one sensor unit which is arranged in the main direction of travel of the industrial truck and is designed to be able to detect obstacles in a predetermined angular range, as well as to an industrial truck which is designed to carry out such a method during its operation.
[0002] During regular use of transport equipment in logistics facilities, collisions between industrial trucks and warehouse equipment, industrial trucks and other vehicles, or industrial trucks and people can occur more frequently, especially during peak times. One approach to counteracting such collisions could be to use a radio-based system that informs the industrial trucks about the presence of obstacles. However, it has been shown that the currently used sensor technology leads to unnecessary braking and thus limits the performance of such vehicles.
[0003] In order to also include objects and persons without such radio equipment in the protection concept, it is known to use sensor units in industrial trucks. These units check the surrounding area for obstacles and can be mounted and aligned on the industrial truck, in particular in the main direction of travel. The corresponding sensor units create so-called protective fields, which are often located in horizontal planes just above the driving surface and whose dimensions and alignment can be partially adapted to the current driving state of the industrial truck, for example, their alignment to a current steering angle and their length to a current vehicle speed, in order to enable controlled braking in any case if an obstacle is detected in such a protective zone.
[0004] If such a sensor unit detects an object, corresponding information can be generated and / or a vehicle reaction or action triggered. Naturally, it is desirable for a corresponding vehicle to only react or initiate a measure if a collision is indeed possible and likely, i.e., if an obstacle is located within the vehicle's intended range of motion. For this purpose, the protection zone will, as already mentioned, depend on the current steering angle or direction of travel of the corresponding industrial truck, since these parameters determine the area of the road surface that will soon be traveled through.
[0005] Accordingly, in known systems for obstacle handling in industrial trucks, the future path is calculated in advance for a specific period of time using the steering angle determined by a corresponding sensor unit and the known current speed of the vehicle, and evaluated for the presence of an obstacle. If an obstacle is found in this path, the system triggers the corresponding predetermined reaction or action.
[0006] However, particularly with personnel-operated industrial trucks, there is the problem that in certain driving situations the operator may wish to initially drive towards an obstacle up to a certain distance, but to turn away from the obstacle in a controlled manner before a collision or to change the direction of travel of the vehicle in a way that means approaching the obstacle but ultimately represents planned and safe behaviour of the vehicle.
[0007] An example of this could be when such an industrial truck enters an aisle, for example a racking aisle, where, during the corresponding curve to enter the aisle, a pure extrapolation of the curve into the future would identify the inside rack as an obstacle and trigger the collision avoidance system accordingly, even though the situation is desired and under control by the operator and therefore does not pose any danger under normal circumstances. Rather, it can be assumed that during such a maneuver, the industrial truck operator will correct the steering in good time, for example, straighten out, as soon as the truck has turned onto a curve parallel to both sides of the aisle, even though during the actual curve or turning into the aisle the pre-calculated path of the industrial truck will at least temporarily extend into the racking wall.
[0008] In order to avoid the triggering of false positive hazard detections and the corresponding triggering of countermeasures in such situations, which could impair or irritate the operator of the vehicle when carrying out their work, there is a need to reliably detect such operating situations and to provide a method with which corresponding predetermined measures for collision prevention or obstacle handling are only triggered in situations in which it is assumed that an operator does not have the industrial truck under control in the intended manner or is carrying out a dangerous driving maneuver in the vicinity of an obstacle.
[0009] To achieve the above-mentioned object and to provide a collision avoidance system or a method for obstacle handling which actually only intervenes in critical situations or triggers predetermined measures, the invention first proposes such a method, comprising detecting a current speed and a current steering angle to the right or left of at least one steered wheel of the industrial truck by means of a speed sensor or a steering angle sensor of the industrial truck, calculating a protection zone based on the current speed and the current steering angle, evaluating the data supplied by the at least one sensor unit within the protection zone of the industrial truck, and, if an obstacle is detected in the protection zone, determining a respective right and left steering angle difference to the current steering angle,by means of which the obstacle can be avoided, or determining a right or left steering angle difference to the current steering angle, by means of which the obstacle can be avoided, in the direction of straight-ahead travel, depending on whether there is a current steering angle to the left or right, and suppressing at least one predetermined measure if there is a current steering angle to the right and the current steering angle to the right is greater than or equal to the left steering angle difference, or there is a current steering angle to the left and the current steering angle to the left is greater than or equal to the right steering angle difference, otherwise the at least one predetermined measure is triggered.
[0010] In addition, the method can include an assessment of whether there is a possible free path to the right or left of the obstacle, based on the current speed and a predetermined time period, wherein the predetermined measure is only suppressed if, in addition to the above-mentioned conditions, there is also a left-hand free path with a current steering angle to the right or if there is also a right-hand free path with a current steering angle to the left.
[0011] Accordingly, according to the invention, when an obstacle occurs in the protection zone defined based on the current speed and steering angle of the vehicle, alternative paths are sought to the right and left of the obstacle, each of which corresponds to cornering with a constant steering angle. In this context, the protection zone initially corresponds to a projected path of the industrial truck based on the current speed and steering angle for a predetermined time, and it can also be required that a possible clear path must have a certain length, which also depends on the current speed and, accordingly, a predetermined time period. In this context, it should also be noted that a wheel speed sensor or any other suitable device can be used as a speed sensor.
[0012] Furthermore, the right and left steering angle differences are used to calculate the minimum steering angle changes that a vehicle operator would need to make to be able to drive past the obstacle. Accordingly, the two steering angle differences to the right and left, as well as the information regarding whether a clear path has been found, serve as input variables for determining whether at least one predetermined action should be suppressed if an obstacle has indeed been detected in the protection zone, with the triggering of the action initially assumed to be normal.
[0013] According to the logic developed on this basis, actual dangerous situations are differentiated from situations in which an operator of the industrial truck performs safe and controlled cornering. In particular, cases in which an industrial truck turns into an aisle and the predicted trajectory of the industrial truck briefly extends into a lateral barrier of the aisle can be handled in an advantageous manner, but it is still assumed that the operator will correct the vehicle in time to drive straight ahead or similarly before a dangerous situation actually occurs are exempted from a measure by the logic according to the claim only those cases in which the driver can avoid a detected obstacle by steering straight ahead out of a corner. However, the following atypical cases are not exempted, if the driver is driving straight towards an obstacle: here the steering angle difference necessary for evasive action cannot be smaller than the current steering angle, which is already 0, the driver would have to steer to the other side beyond straight steering to avoid the obstacle the driver would have to steer more sharply into the curve to avoid the obstacle.
[0014] In this case, the at least one predetermined measure can comprise reducing the current and / or maximum speed of the industrial truck. In this way, in an identified actual hazardous situation, the truck can first be decelerated, which will automatically affect the dimensions of the protective field in front of the vehicle, thus ensuring that the vehicle will always come to a stop before colliding with the obstacle. Ultimately, as deceleration occurs, the protective field will become increasingly shorter until both the speed and the length of the protective field itself finally return to zero.
[0015] Alternatively or additionally, the at least one predetermined measure may comprise issuing a corresponding message to an operator, for example an acoustic warning of a dangerous situation, or issuing a visual warning, such as a warning by flashing an LED or displaying a warning on a screen.
[0016] It would also be conceivable that the at least one predetermined measure could comprise a steering intervention to avoid the detected obstacle in the protection zone, which requires direct intervention in the control system of the corresponding industrial truck.
[0017] In connection with the examples of predetermined measures just mentioned, it should also be pointed out that these can also be combined in a graduated manner, i.e. that, for example, if a steering intervention is necessary below a predetermined threshold value, a warning could first be issued and if the threshold value is exceeded, an intervention in the vehicle control could be carried out, i.e. an automatic braking and / or evasive maneuver.
[0018] Furthermore, in the method according to the invention, determining the right and left steering angle difference and / or evaluating the possible free travel path can include taking into account the geometric dimensions of the industrial truck and / or a load carried by it. In this way, the steering angle differences and travel paths are evaluated or determined as accurately as possible. Alternatively, however, a collision zone defined independently of the actual dimensions of the industrial truck could also be assumed, which could, for example, include additional tolerances or simplifications of the vehicle geometry.
[0019] According to a second aspect, the present invention relates to an industrial truck which is designed to carry out a method of the type just described during its operation, comprising a vehicle body, at least one sensor unit which is arranged in the main direction of travel of the industrial truck and is designed to be able to detect obstacles in a predetermined angular range, a speed sensor and a steering angle sensor, and a control unit which is designed to receive data from the speed sensor and the steering angle sensor, to calculate a protection zone, and to determine a right and a left steering angle difference from the current steering angle, by means of which an obstacle detected in the protection zone can be avoided, if necessary.to assess whether there is a possible clear path to the right or left of the obstacle and to decide, based on the presence of a clear path and the steering angle differences, whether or not at least one predetermined measure should be triggered in accordance with the method described above.
[0020] In this case, the at least one sensor unit can comprise, for example, a LIDAR unit and / or it can be a manually guided industrial truck, i.e., an industrial truck that is directly controlled by an operator. Although a corresponding method according to the invention could, in principle, also be used in autonomous or semi-autonomous vehicles, the underlying concept of intentionally approaching an obstacle before corresponding counter-steering plays only a minor role, since when planning a route in an autonomous vehicle, the intended route of the corresponding control unit should always be known.
[0021] Further features and advantages of the present invention will become even clearer from the following description of an embodiment thereof, and in particular of various operating situations of a corresponding industrial truck, when considered together with the accompanying figures. These show in detail: Figures 1 to 3 are explanatory schematic representations to illustrate possible operating situations during operation of an industrial truck according to the invention; and Figures 4 to 8 are explanatory schematic representations to illustrate operating situations of the industrial truck from the Figures 1 to 3 when entering an alley.
[0022] The Figures 1 to 3 show, firstly, in a schematic plan view, different operating situations of an industrial truck 10 according to the invention, wherein in the Figures 1 and 2a free-standing obstacle H is present directly in front of or diagonally in front of the industrial truck 10, while in Figure 3 a wall W is located in the vicinity of the industrial truck 10 or on its current extrapolated trajectory.
[0023] The industrial truck 10 has a vehicle body 12 and a load-handling device 14, on which a load (not shown here) can be transported. Furthermore, the industrial truck 10 comprises a sensor unit 16, which is arranged at the front of the industrial truck 10 along the main direction of travel L and can, for example, cover an angular range of at least 180°. Furthermore, the industrial truck 10 comprises a pair of unsteered wheels 18 arranged in the region of the load-handling device 14, as well as a steered drive wheel 20. In the case shown here, the industrial truck 10 is a manually guided industrial truck, which is intended and configured for transporting objects in logistics facilities. For this purpose, it further comprises a control unit 22, shown only schematically, as well as speed and steering angle sensors (not shown), which, like the sensor unit 16, deliver their data to the control unit 22.For reasons of clarity, some of the components of the industrial truck 10 mentioned here are only shown in some of the figures, but it is understood that the industrial truck 10 is the same in all figures.
[0024] Furthermore, in the Figures 1 to 3 Each of these zones shows a protection zone Z of the industrial truck 10, which is determined based on the current speed of the industrial truck 10 and the current steering angle α of the vehicle 10 in relation to the main direction of travel L. The industrial truck 10 travels in Figure 1 currently straight ahead, so that the steering angle α is currently 0°, while in the Figures 2 and 3 each time executes left turns with a specific instantaneous steering angle α.
[0025] Furthermore, in the Figures 1 to 3In dashed lines, possible free routes or alternative routes past the obstacle H or the wall W are shown, which just allow passing the corresponding obstacle H or the wall W with a minimum distance. While in the Figures 1 and 2 left and right free travel paths exist, exists in the operating situation from Figure 3 Only one free path to the left is allowed, since the wall W prevents evasion to the right. The corresponding left and right free paths correspond to the right and left steering angle differences to the current steering angle α, by which the obstacle can just be avoided, and are denoted by β and γ. Accordingly, it should be noted that the two angles β and γ are each to be considered relative to the current steering angle α, and this, in turn, is to be considered relative to the main driving direction or straight-ahead driving direction L.
[0026] By means of the method according to the invention, it can now be determined whether a predetermined measure for avoiding the obstacles H or the wall W is to be triggered, i.e. in particular a reduction of the current and / or maximum speed of the industrial truck, an output of a corresponding message to the operator of the industrial truck 10 or even an automated steering intervention.
[0027] Within the scope of the method according to the invention, in all situations from the Figures 1 to 3 assumed that the initiation of a corresponding predetermined measure will be necessary, since in the Figures 1 and 2 in each case the vehicle is driven directly towards the free-standing obstacle H and accordingly no attempt is made to avoid it, while in the Figure 3 the steering angle is too small and therefore a collision with the wall W must be assumed.
[0028] The corresponding input data for determining whether the at least one predetermined measure is to be triggered, as well as the procedure based on this, are also contained in the Figures 1 to 3 schematically represented using a diagram, i.e., in particular, whether a right-hand or left-hand bend is being negotiated, whether a right and / or left-hand evasive route is found, and whether a corresponding steering angle is greater or smaller than a corresponding steering angle difference. The corresponding evaluations in each case indicate that suppression of the at least one predetermined measure is not necessary, since the combination of conditions according to the invention is not met, whereupon the corresponding measure is to be triggered.
[0029] In contrast, in the Figures 4 to 8The respective operating situations when the industrial truck 10 enters an aisle G, which is delimited on its right and left sides by a right wall W1 and a second wall W2. Here, the industrial truck 10 begins in Figure 4 just as it enters the aisle G, ie the steered wheel 20 currently has a steering angle which will trigger a right turn of the industrial truck 10 into the aisle G. However, since there is currently no obstacle in the protection zone Z, there is no need in this case to check whether a predetermined measure for obstacle handling should be triggered.
[0030] In contrast, Figure 5 the industrial truck 10 has already passed through part of the curved path to the entrance into the aisle G and the protective field Z comes into contact with the right wall W1 of the aisle G for the first time at this moment. Figure 5a steering angle α of 30° is assumed, while at the same time it is determined that a left-hand avoidance path exists and a left-hand steering angle difference β must be only 10°, as shown by the dashed outline in Figure 5 indicated. Accordingly, the current steering angle α to the right is greater than the determined left steering angle difference β, and the triggering of the predetermined measure is suppressed according to the invention, since this is, by definition, a normal operating situation of the industrial truck 10 and it is assumed that the operator of the industrial truck 10 will straighten the steering in time so that a collision with the wall W1 will not occur.
[0031] Also in the Figure 6In the situation shown, in which the industrial truck 10 is now aligned substantially parallel to the walls W1 and W2 with respect to its main direction of travel L, the at least one predetermined measure continues to be suppressed, since the determined left evasive angle β of 20° continues to be smaller than the instantaneous steering angle α of 30° and consequently the conditions for suppressing the predetermined measure continue to be met.
[0032] In contrast, Figure 7 represents the limiting case in which the current steering angle α remains 30°, but the left evasion angle β is also 30°. Therefore, if in this situation the operator of the industrial truck 10 does not immediately initiate a countermeasure and in particular a countersteering to the left, the case from Figure 8occur in which the left evasive angle β is now 35°, while the current steering angle α is still 30°, so that at this point the condition for suppressing the at least one predetermined measure is no longer met and this will therefore be triggered.
[0033] Consequently, the Figures 4 to 8 understand that a normal controlled entry into an aisle G is possible without at least one predetermined measure being triggered, while only if the operator of the industrial truck 10 fails to straighten or counter-steer the vehicle in time will the predetermined measure be triggered at a certain point in time, whereby this point in time depends on the current speed of the industrial truck 10, since this is included both in the dimensions of the protection zone Z and in the determination of the free travel path to the left.
Claims
1. A method for obstacle handling in an industrial truck (10), which comprises at least one sensor unit (16) which is arranged in the main direction of travel (L) of the industrial truck (10) and is designed to be able to detect obstacles (H, W, W1, W2) in a predetermined angular range, the method comprising: - detecting a current speed and a current steering angle (α) to the right or left of at least one steered wheel (20) of the industrial truck (10) by means of a speed sensor or a steering angle sensor of the industrial truck (10); - calculating a protection zone (Z) based on the current speed and the current steering angle; - evaluating the data supplied by the at least one sensor unit (16) within the protection zone (Z) of the industrial truck (10);and - when an obstacle (H, W, W1, W2) is detected in the protection zone (Z): o Determining a right and a left steering angle difference (γ, β) from the current steering angle (α), by means of which the obstacle (H, W, W1, W2) can be avoided in each case, or determining a right or left steering angle difference (γ, β) from the current steering angle (α), by means of which the obstacle (H, W, W1, W2) can be avoided, in the direction of straight-ahead travel, depending on whether there is a current steering angle (α) to the left or right; o Suppressing at least one predetermined measure if: ▪ there is a current steering angle (α) to the right and the current steering angle (α) to the right is greater than or equal to the left steering angle difference (β); or ▪ there is a current steering angle (α) to the left and the current steering angle (α) to the left is greater than or equal to the right steering angle difference (y); o otherwise: triggering of the at least one predetermined measure.; 2. Method according to claim 1, further comprising evaluating whether a possible free path to the right or left of the obstacle (H, W, W1, W2) exists on the basis of the current speed and a predetermined time period, wherein the predetermined measure is only suppressed if, at a current steering angle (α) to the right, there is additionally a left free path or if, at a current steering angle (α) to the left, there is additionally a right free path.
3. Method according to claim 1 or 2, wherein the at least one predetermined measure comprises reducing the current and / or a maximum speed of the industrial truck (10).
4. Method according to one of the preceding claims, wherein the at least one predetermined measure comprises issuing a corresponding message to an operator.
5. Method according to one of the preceding claims, wherein the at least one predetermined measure comprises a steering intervention to avoid the obstacle (H, W, W1, W2).
6. Method according to one of the preceding claims, wherein the determination of the right and left steering angle difference (γ, β) and / or the evaluation of the possible free travel path comprises taking into account geometric dimensions of the industrial truck (10) and / or a load carried thereby.
7. Industrial truck (10) which is designed to carry out a method according to one of the preceding claims during its operation, comprising: - a vehicle body (12); - at least one sensor unit (16) which is arranged in the main direction of travel (L) of the industrial truck (10) and is designed to be able to detect obstacles (H, W, W1, W2) in a predetermined angular range; - a speed sensor and a steering angle sensor; and - a control unit (22) which is designed to: o receive data from the speed sensor and the steering angle sensor; o calculate a protection zone (Z); o determine a right and a left steering angle difference (γ, β) from the current steering angle (α), by means of which an obstacle (H, W, W1, W2) detected in the protection zone (Z) can be avoided; o if necessary.to assess whether there is a possible clear path to the right or left of the obstacle (H, W, W1, W2); and o to decide, based on the presence of a clear path and the steering angle differences (γ, β), whether at least one predetermined measure should be triggered.
8. Industrial truck (10) according to the preceding claim, wherein the at least one sensor unit (16) comprises a LIDAR unit.
9. Industrial truck (10) according to one of claims 7 and 8, wherein it is a manually guided industrial truck (10).