METHOD FOR OPERATING A AT LEAST PARTIALLY AUTOMATED INSTALLATION VEHICLE

Description

[0001] The invention relates to a method for operating an industrial truck that can be operated at least partially automatically. Furthermore, a computer program, a machine-readable storage medium, a control unit, and an industrial truck are also described.

[0002] At least partially automated or even autonomously operated industrial trucks are known; these can generally also be referred to as (automated or autonomous) industrial trucks (English: Automated Guided Vehicles ; abbreviated: AGVs). Such industrial trucks are defined, for example, in EN 1525. According to EN 1525, an industrial truck must clearly indicate its intended direction of travel as soon as it approaches points where it can proceed in more than one direction.

[0003] In US 2014 / 316633 A1, US 2019 / 220005 A1, the publication by Gunter Ullrich et al.: "Driverless Transport Systems: A Primer - with Practical Applications - on Technology - for Planning", January 19, 2011 (2011-01-19), XP055525050, ISBN: 978-3-8348-0791-5, JPH0685135B2, and JP2015170284A, methods for operating at least partially automated industrial trucks are described. The Wikipedia article "Direction Indicator" from September 18, 2020, reveals that a turn signal failure can be indicated to a motor vehicle driver.

[0004] Based on this, the invention aims to at least partially solve the disadvantages and problems described in connection with the prior art. In particular, it seeks to improve personal safety during changes of direction in a partially automated industrial truck.

[0005] These tasks are solved by the features of the respective independent claims. Advantageous embodiments result from the dependent claims.

[0006] This is achieved through a method for operating an industrial truck that can be operated at least partially automatically, in which at least the following steps are carried out automatically by the industrial truck: a) Recognizing that the industrial truck is approaching a point where it is to change its direction of travel, b) Checking at least one predefined direction change criterion for the intended change of direction, wherein the at least one predefined direction change criterion requires that a specific direction change signal (3) of the industrial truck (1) to be displayed for the intended change of direction is activated, c) Stopping the industrial truck if the at least one direction change criterion is not met.

[0007] Steps a), b), and c) can be performed at least once and / or repeatedly in the specified order to carry out the procedure. In particular, step b), or steps b) and c), can be repeated several times in succession (possibly even during changes of direction). The procedure can be carried out, for example, using a control unit and / or a forklift truck, both of which are also described herein. Advantageously, at least steps a), b), and c) can be performed autonomously by the forklift truck.

[0008] The method advantageously contributes to improved personal safety during changes of direction. Furthermore, the method can facilitate the automated, controlled, and monitored cornering, particularly by monitoring vehicle speed and / or rotational speed.

[0009] The industrial truck can be, for example, one as defined in EN 1525. The industrial truck can be equipped for at least partially automated and / or autonomous (driving) operation. The industrial truck typically has a loading platform. Furthermore, the industrial truck can have a front structure. The front structure can have a substantially vertical rear wall facing the loading platform.

[0010] In step a), the system recognizes that the forklift is approaching a point where it is to change direction. In other words, the forklift recognizes that it is to approach, or is approaching, a point where it is to change direction. Specifically, it recognizes that it is to approach, or is approaching, a fork in the road. This point could be, for example, a specific location on the forklift's planned route.

[0011] In step b), at least one predefined direction change criterion is checked (or monitored) for the intended change of direction. The intended change of direction can be, in particular, a change to the left or a change to the right. In other words, the change of direction can involve, in particular, a turning maneuver and / or cornering. Several predefined direction change criteria can also be checked or monitored in step b). The checking or monitoring can be performed permanently or continuously. The checking or monitoring can be carried out before and / or during the change of direction or before and / or during cornering.

[0012] In step c), the forklift truck stops if at least one direction change criterion is not met. This direction change criterion is typically a positively defined criterion. Specifically, the direction change criterion is considered "not met" if a (positively defined) expected (criterion) state is not reached or has not been reached. In other words, the direction change criterion is, for example, "not met" if there is a deviation from a (positively defined) expected (criterion) state. After step c), the forklift truck may also be allowed to proceed if at least one direction change criterion is met again.

[0013] At least the checking or monitoring according to step b) and / or the stopping that may be required according to step c) can advantageously be carried out with a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849.

[0014] Steps a) to c), or at least steps b) and c), or in particular at least step b), can be performed by a safety control device of the industrial truck, for example, a safety control module of a control unit of the industrial truck, which, in addition to a driving control device of the industrial truck, for example, comprising a robot control module and / or a motion control module of the control unit of the industrial truck, is present. The driving control device, in particular the motion control module, generally effects the (actual) driving control or driving operation and its modification(s), for example, by appropriately controlling or specifying target speeds of the motors and / or the driven wheels of the industrial truck. In addition, the driving control device, in particular the motion control module, can specify the direction of travel, in particular at least one direction change signal to be displayed.

[0015] The at least one predefined direction change criterion requires that a specific direction change signal on the industrial truck be activated to indicate the intended change of direction. In this context, it may be required, for example, that a specific turn signal or group of turn signals indicating the intended change of direction be activated (e.g., left turn signal(s) for a left turn and / or right turn signal(s) for a right turn). This can contribute to providing effective monitoring of the direction indication requirements, particularly to preventing erroneous indications.

[0016] The safety control device (explained above), in particular the safety control module, can check and monitor whether the direction indicator is correctly and appropriately set by the vehicle control unit. Thus, the safety control device can, for example, monitor whether a turn signal (indicator) is consistent with the actual vehicle control.

[0017] In a further advantageous embodiment, it is proposed that at least one predefined direction change criterion requires that a specific direction change signal of the industrial truck, indicated for the intended change of direction, has been active for a predefined lead time before the direction change is initiated. This advantageously contributes to ensuring that persons in the vicinity of the industrial truck have sufficient time to perceive the direction change signal before the industrial truck changes its direction and / or that changes of direction that are not indicated in time can be advantageously prevented.

[0018] In a further advantageous embodiment, it is proposed that at least one predefined criterion for changing direction requires that the speed of the industrial truck be less than or equal to a predefined limit. In particular, the limit for cornering is lower than the limit for straight-line travel. This can also contribute to improved personal safety, as people in the vicinity of the industrial truck can generally react better to a slower change of direction (compared to straight-line travel).

[0019] In a further advantageous embodiment, it is proposed that at least one predefined direction change criterion requires that the rotational speed of the industrial truck be less than or equal to a predefined limit value dependent on the (linear) travel speed of the industrial truck. Furthermore, the limit value for the rotational speed can be defined depending on the type of direction change, in particular to the left (positive limit value for the rotational speed) or to the right (negative limit value for the rotational speed). The dependence of the rotational speed on the (linear) travel speed can advantageously contribute to achieving advantageous straightness when cornering and / or to ensuring that a specific, in particular minimum, turning radius can be controlled and monitored.

[0020] In this context, the direction change criterion can also be predefined (alternatively or cumulatively) depending on the direction change indicator and / or the direction change signal. For example, the direction change criterion relating to the rotational speed can be predefined depending on whether at least one left-hand direction change signal or at least one right-hand direction change signal is active. This can advantageously contribute to monitoring the curve radius as reliably as possible, dependent on the direction change signal (flashing).

[0021] In particular, the (above-described) safety control device, especially the safety control module, can check and monitor whether an expected curve path (especially one specified and / or controlled by the vehicle control unit) is being followed. For example, the safety control device may be designed to stop the industrial truck if it deviates from an expected curve path.

[0022] In a further advantageous embodiment, it is proposed that the at least one predefined direction change criterion is checked (at least even after a turn has been initiated). In other words, this can be described as meaning that the at least one predefined direction change criterion continues to be checked even after a turn has been initiated. For example, the at least one predefined direction change criterion can be checked before and during the turn.

[0023] Another aspect proposes a computer program for carrying out a procedure described here. In other words, this specifically concerns a computer program (product) comprising instructions that, when executed by a computer, cause it to perform a procedure described here.

[0024] Another aspect that is proposed is a machine-readable storage medium on which the computer program is stored. This machine-readable storage medium is typically a computer-readable data carrier.

[0025] In addition, a control unit for a partially automated industrial truck is proposed, configured to carry out a procedure described herein. The control unit (controller) can, for example, include a computer capable of executing commands to perform the procedure. For this purpose, the computer or control unit can, for example, execute the specified computer program. For instance, the computer or control unit can access the specified storage medium to execute the computer program. The control unit can, for example, be a safety control unit. Alternatively or cumulatively, the procedure can, for example, be performed by a safety control module of the control unit. Furthermore, the control unit can also include a robot control module and / or a motion control module.

[0026] Another aspect proposes a forklift truck capable of at least partial automation, equipped with a control unit. Alternatively or cumulatively, this can also be described as a forklift truck capable of at least partial automation, designed to carry out a procedure described herein. Furthermore, the forklift truck is generally configured for at least partially automated or autonomous (driving) operation.

[0027] In summary, a particularly advantageous embodiment of the solution described here can also be described as follows: a safety control unit (SCU) in a partially automated industrial truck (especially an autonomous transport vehicle) monitors whether a turning signal (turn signal) corresponds to the actual driving control of the vehicle. Furthermore, it can be provided that if the vehicle deviates from an expected curve, it is stopped and thus brought into a safe state.

[0028] The details, features, and advantageous configurations discussed in connection with the process may also occur in the computer program, storage medium, control unit, and / or industrial truck presented here, and vice versa. In this respect, full reference is made to the explanations provided therein for a more detailed characterization of the features.

[0029] The solution presented here and its technical context are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations explained in the figures and combine them with other components and / or findings from other figures and / or the present description. The following is shown by way of example and schematically: Fig. 1: an exemplary sequence of the method presented here, Fig. 2: an embodiment of a forklift truck described here in sectional view, Fig. 3: a graphic representation of predefined limit values ​​for an embodiment of the method, and Fig. 4-7: an advantageous application of the method described here in top view.

[0030] Fig. 1 Figure 1 schematically illustrates an exemplary sequence of the procedure presented here. The procedure is used to operate a forklift truck 1 that can be operated at least partially automatically (see Figure 1). Fig. 2 and 4 bis 7 The sequence of steps a), b), and c) shown in blocks 110, 120, and 130 is exemplary and can be performed at least once in the sequence shown to carry out the procedure. Step b) can be repeated several times in succession (possibly even during the change of direction). In addition, steps a) to c) are performed automatically by the industrial truck (1).

[0031] In block 110, according to step a), it is detected that the industrial truck 1 is approaching a point 2 where it is to change its direction of travel. In block 120, according to step b), at least one predefined direction change criterion is checked for the intended change of direction. In block 130, according to step c), the industrial truck 1 is stopped if at least one direction change criterion is not met.

[0032] Fig. 2 Figure 1 schematically shows a sectional representation of an embodiment of the industrial truck 1 described herein. The industrial truck 1 is equipped for at least partially automated or autonomous (driving) operation. Furthermore, the industrial truck 1 is equipped to carry out a procedure described herein. For this purpose, the industrial truck 1 includes, by way of example, a control unit 8, also described herein. The industrial truck 1 also includes, by way of example, a front structure 10 and a loading platform 9. For example, the front structure 10 has a substantially vertical rear wall 11 facing the loading platform 9. The loading platform 9 serves in particular to accommodate a goods carrier 18 (see Figure 1). Fig. 4 ), which can be transported using the industrial truck 1.

[0033] The industrial truck 1 typically has four direction-of-travel signals 3 to indicate the direction of travel, which may be designed in the form of a flashing light. The direction-of-travel signals 3 usually consist of a front, right-hand direction-of-travel signal 3a, a rear, right-hand direction-of-travel signal 3b, a rear, left-hand direction-of-travel signal 3c, and a front, left-hand direction-of-travel signal 3d (viewed in the direction of travel).

[0034] The control unit 8 comprises, for example, a robot control module 12 (RCU), a motion control module 13 (MCU), and a safety control module 14 (SCU). To carry out the procedure, the control unit 8 can be configured, for example, for the procedure described below.

[0035] The robot control module 12, for example, sends the desired travel speed 4 and the direction of travel, in particular the direction change signals 3 (right, left, off) to be activated, to the motion control module 13. This is an example of how, and if applicable, how, according to step a), it can be recognized (by the robot control module 12 and / or the motion control module 13) that the industrial truck 1 is approaching a point 2 where it is to change its direction of travel.

[0036] The motion control module 13 transmits the desired direction of travel, in particular the direction change signals 3 (right, left, off) to be activated, to the safety control module 14. Thus, the safety control module 14 can also recognize, as in step a), that the industrial truck 1 is approaching a point 2 where it is to change its direction of travel. Furthermore, the motion control module 13 calculates, as an example, the target rotational speeds of the driven wheels 17 of the industrial truck 1 and transmits these to a motor unit 15 of the industrial truck 1.

[0037] The motor unit 1 can have one or more (electric) motors, which may be operatively connected to the driven wheels 17 of the industrial truck via a gearbox or directly, possibly in the sense of individually driven wheels. Furthermore, in Fig. 2 shown that the industrial truck 1 can, for example, have one or more speed sensors 16 (for example, SIL2 rotary sensors) which can transmit the actual rotational speeds of the motors or wheels 17 to the safety control module 14.

[0038] The safety control module 14, for example, activates the direction change signals 3 (right, left, off) or switches on the turn signals (right, left, off) depending on the desired direction of travel. Furthermore, the safety control module 14 can, for example, time the duration that the direction change signals 3 or turn signals are active. The safety control module 14 also calculates, for example, the instantaneous (linear) driving speed 4 and the (instantaneous) rotational speed 5 (about the vertical axis 23, cf.) from the actual rotational speeds. Fig. 7 ) of the industrial truck 1.

[0039] In particular, the safety control module 14 can (permanently) monitor the instantaneous (linear) travel speed 4. When the industrial truck 1 is traveling straight ahead, the safety control module 14 can advantageously and safely stop it at a (linear) travel speed 4 above a predefined limit value of, for example, 1,000 mm / s, with, for example, a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849.

[0040] Furthermore, the safety control module 14 can, for example, (permanently) determine the instantaneous rotational speed 5 (around the vertical axis 23, cf. Fig. 7 ) of the industrial truck 1. In particular, the safety control module 14 can advantageously bring the industrial truck 1 to a safe stop when traveling straight ahead at a rotational speed 5 (symbol: ω) outside a predefinable, permissible range of values ​​of, for example, -0.14 / s < ω < +0.14 / s, with, for example, a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849.

[0041] Furthermore, the safety control module 14 can be configured here, for example, to check at least one predefined direction change criterion for the intended change of direction. As a direction change criterion(s), the safety control module 14 can, in particular, check whether the correct direction change signal 3 is activated, whether the direction change signal 3 of the industrial truck 1 was active for a predefined lead time before initiating the direction change, whether the travel speed 4 of the industrial truck 1 is less than or equal to a predefined limit value 5, and / or whether the rotational speed 6 of the industrial truck 1 is less than or equal to a predefined limit value 7 that depends on the travel speed 4 of the industrial truck 1.

[0042] The safety control module 14 monitors whether the correct turn signal, the wrong turn signal, or no turn signal has been activated.

[0043] For example, the safety control module 14 can monitor whether the turn signal for the intended direction of travel or change of direction was active for the entire lead time or not yet for the entire lead time. This illustrates that, and possibly how, at least one predefined direction change criterion can require that a specific direction change signal 3 of the industrial truck 1, which is to be displayed for the intended change of direction, was active for a predefined lead time before the direction change was initiated.

[0044] For example, the safety control module 14 can monitor whether the current (linear) travel speed 4 is greater than or less than a predefined limit 5 (e.g., 700 mm / s for cornering) or less than or equal to the predefined limit 5. This illustrates that, and possibly how, at least one predefined direction change criterion can require that the travel speed 4 of the industrial truck 1 is less than or equal to a predefined limit 5.

[0045] For example, the safety control module 14 can monitor whether an extended range of values ​​for the rotational speed (symbol: ω) (compared to the one explained above for straight-ahead travel) from, for example, ω max,right = -1.05 / s - v / m (right turn signal) to ω max,left = 1.05 / s - v / m (left turn signal) is exceeded (or has been exceeded) or maintained. Here, v represents the symbol for the (linear) travel speed 4. Alternatively, this relates to a range of values ​​from -1.05 / s - v / m < ω < 1.05 / s - v / m. This illustrates that, and possibly how, at least one predefined direction change criterion can require that the rotational speed 6 of the industrial truck 1 is less than or equal to a predefined limit value 7, which depends on the travel speed 4 of the industrial truck 1.The limit value 7 can (also) be predefined depending on the direction of the change of direction (left / right), for example as -1.05 / s - v / m for a change of direction to the right and as +1.05 / s - v / m for a change of direction to the left (where the signs can also be defined in reverse, depending on the definition of the reference rotation direction).

[0046] The first two of the aforementioned direction change criteria are preferably checked before initiating the turn, and in particular, the turn is only initiated if the check is successful. Furthermore, these direction change criteria, especially the first of the aforementioned criteria, can also be checked (further) during the turn. In particular, the last two of the aforementioned direction change criteria are preferably also checked at least during the turn, in order to achieve advantageous straightness during the turn and / or to ensure that a specific, especially minimum, turning radius is maintained in a controlled or monitored manner. This also provides an example of how, and if applicable, the at least one predefined direction change criterion is (also) checked after a turn has been initiated.In other words, at least one predefined direction change criterion can be tested here as an example before and during cornering.

[0047] The safety control module 14 can advantageously and safely stop the industrial truck 1 with, for example, a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849, if one or more of the direction change criteria are not met. This provides an example of how, and if applicable, how, the industrial truck 1 can be stopped according to step c) if at least one direction change criterion is not met.

[0048] For example, the safety control module 14 can advantageously and safely stop the industrial truck 1 when it is cornering at a (linear) travel speed 4 above a predefined limit 5 of, for example, 700 mm / s, with, for example, a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849. Furthermore, the safety control module 14 can advantageously and safely stop the industrial truck 1 when it is cornering at a rotation speed 5 (symbol: ω) outside a predefined, permissible range of values ​​of, for example, -1.05 / s - v / m < ω < +1.05 / s - v / m, with, for example, a specific Performance Level (PLr), in particular with a PLr d according to ISO 13849.

[0049] In principle, several of the exemplary direction change criteria can also be tested, at least partially in parallel or simultaneously. According to a particularly preferred combination of direction change criteria to be tested or already tested, the following procedure can be followed in step b): If the right turn signal (direction change signals 3a and 3b) or the left turn signal (direction change signals 3c and 3d) is active for a (the entire) predefined lead time, the safety control module 14 extends the value range at a linear driving speed 4 from, for example, up to (a maximum of) 700 mm / s (limit value 5) to ω = 1.05 / s - v / m (left turn signal) or to ω = -1.05 / s - v / m (right turn signal) (limit value 7). If the extended value range (or the limit value 7) is exceeded, the safety control module 14 stops the industrial truck 1 advantageously safely with PLr d according to ISO 13849.The advantageous limitation of the rotational speed as a function of the linear speed can advantageously contribute to the driving stability of the industrial truck 1 when cornering.

[0050] Fig. 3 Figure 5 schematically shows a graphical representation of predefined limit values ​​5 and 7 for one implementation variant of the procedure. According to the representation shown in Figure 7, the following applies: Fig. 3 The (linear) driving speed 4 is plotted against the rotational speed 6.

[0051] In this context, particular reference is made to the examples in the following to explain and define the linear direction (longitudinal direction) and the direction of rotation. Fig. 7 Reference is made to the reference axes of the industrial truck 1, in particular the longitudinal axis 21, the transverse axis 22 and the vertical axis 23. The linear travel speed usually refers to the speed or speed component of the industrial truck 1 parallel to the longitudinal axis 21. The rotational speed 6 usually refers to the rotational speed about the vertical axis 23.

[0052] According to an advantageous embodiment, during cornering, it can be checked or monitored in particular that the value pair of driving speed 4 and rotational speed 6 is within or below the range specified in the Fig. 3 The limits illustrated by example remain. These limits are defined by the upper limit 5 for the (linear) driving speed 4 when cornering and the limit 7 for the rotational speed. Here, limit 7 applies to the rotational speed on the right side of the Fig. 3 for a left turn and the limit value 7 on the left side of the Fig. 3 for a right-hand turn.

[0053] It can also be seen that the limit value 7 is predefined depending on the driving speed 4. For example, the course of the limit value 7 on the right side of the Fig. 3 via the equation ω max,links = 1.05 / s - v / m (left turn signal) and the course of the limit 7 on the left side of the Fig. 3 The equation ω max,right = -1.05 / s - v / m is predefined. Here, the symbols ω represent the rotational speed, v the driving speed, s second, and m meter. The inner vertical lines in Fig. 2 These figures are included for completeness only and illustrate a minimum rotational speed required for cornering. Such minimum rotational speeds are generally known in the relevant area, so they will not be discussed further here.

[0054] Fig. 4 bis 7 The figures schematically show an advantageous application of the method described here in a top view. The planned travel path 19, which the industrial truck 1 is to follow automatically, is shown as a dashed line. Along this travel path 19, the point 2 where the industrial truck 1 is to change its direction of travel is shown.

[0055] In Fig. 4 The situation is illustrated by example in which the industrial truck 1 approaches point 2, where it is to change its direction of travel or where it can continue in more than one direction. Fig. 5 The following example demonstrates that the industrial truck 1 indicates the intended direction of travel in good time, in particular with a predefined lead time (in this example: to the right, by means of the direction change signals 3a and 3b).

[0056] In Fig. 6 The point 2 at which the curve begins was reached. According to an advantageous embodiment of the described method, from this moment onwards a controlled or monitored curve can be achieved by monitoring the driving speed 4 and the rotational speed 6 (see Figure 1). Fig. 7 ) can be carried out automatically. The following examples of implementation can contribute to the direction change criteria explained above: As soon as the curve begins and the rotational speed leaves the range of values ​​for straight-ahead travel (-0.14 / s < ω < 0.14 / s), the industrial truck 1 stops if the wrong turn signal or no turn signal has been activated and optionally if: the turn signal for the intended direction of travel was not yet active for the required lead time, and / or the linear speed is above a limit value (for example: v > 700mm / s), and / or the extended range of values ​​for the rotational speed is exceeded or has been exceeded, for example ω max,left = 1.05 / s - v / m (turn signal left) to ω max,right = -1.05 / s - v / m (turn signal right).

[0057] In Fig. 7 An example of cornering is illustrated where at least one, and in particular all, direction-change criteria (cornering conditions) are met. If at least one, or all, direction-change criteria are met, the industrial truck 1 will not normally stop (except, for example, in the case of an imminent collision with another object or person). The cornering maneuver can be continued as soon as at least one, and in particular all, direction-change criteria are met again.

[0058] In Fig. 7It is further shown by way of example that the direction change criterion usable according to an advantageous embodiment, which requires that the rotational speed 6 of the industrial truck 1 is less than or equal to a predefined limit value 7 depending on the travel speed 4 of the industrial truck 1, can advantageously contribute to achieving advantageous straightness when cornering and / or to ensuring that a certain, in particular minimum, curve radius 20 can be controlled or monitored.

[0059] Thus, a method, a computer program, a machine-readable storage medium, a control unit, and a forklift truck are specified, which at least partially solve the disadvantages and problems described in connection with the state of the art. In particular, with a forklift truck that can be operated at least partially automatically, the safety of persons during changes of direction can be improved. Reference symbol list

[0060] 1. Industrial truck 2. Position 3. Direction change signal 4. Travel speed 5. Limit value 6. Rotation speed 7. Limit value 8. Control unit 9. Loading platform 10. Front structure 11. Rear wall 12. Robot control module 13. Motion control module 14. Safety control module 15. Motor unit 16. Speed ​​encoder 17. Wheel 18. Load carrier 19. Travel path 20. Curve radius 21. Longitudinal axis 22. Transverse axis 23. Vertical axis

Claims

1. Method for operating an industrial truck (1) that can be operated in an at least partially automated manner, in which at least the following steps are carried out in an automated manner by the industrial truck (1): a) detecting that the industrial truck (1) approaches a point (2) at which it is supposed to change its direction of travel, characterized by b) checking at least one predefined direction change criterion for the intended change of direction of travel, the at least one predefined direction change criterion requiring a specific change of direction of travel signal (3) of the industrial truck (1) that can be displayed for the intended change of direction of travel to be activated, c) stopping the industrial truck (1) if the at least one direction change criterion is not met.

2. Method according to Claim 1, wherein the at least one predefined direction change criterion requires a specific change of direction of travel signal (3) of the industrial truck (1) that can be displayed for the intended change of direction of travel to have been active for a predefined lead time prior to initiation of the change of direction.

3. Method according to either of the preceding claims, wherein the at least one predefined direction change criterion requires the driving velocity (4) of the industrial truck (1) to be less than or equal to a predefined limit value (5).

4. Method according to one of the preceding claims, wherein the at least one predefined direction change criterion requires the rotational velocity (6) of the industrial truck (1) to be less than or equal to a limit value (7) predefined on the basis of the driving velocity (4) of the industrial truck (1).

5. Method according to one of the preceding claims, wherein the at least one predefined direction change criterion is checked after cornering has been initiated.

6. Computer program, comprising instructions that, when executed by a computer, cause the computer to carry out the method according to one of Claims 1 to 5.

7. Machine-readable storage medium on which the computer program according to Claim 6 is stored.

8. Control unit (8) for an industrial truck (1) that can be operated in an at least partially automated manner, designed to carry out a method according to one of Claims 1 to 5.

9. Industrial truck (1) that can be operated in an at least partially automated manner, having a control unit (8) according to Claim 8.