DE102018104648A1 - Method and device for collision prevention between an industrial truck and at least one collision partner - Google Patents

Abstract

A method (100) for collision prevention between an industrial truck (11) and at least one collision partner (12) is proposed which comprises detecting (101) at least one collision partner (12) within an observation field (13) about the industrial truck (11) Determining (103) an approach speed to each detected collision partner (12), defining (104) a guard length (18) for each detected collision partner (12) depending on the determined approach speed to the respective collision partner (12), determining (107) a distance (19) to each detected collision partner (12), comparing (108) the distance (19) with the guard length (18) for each detected collision partner (12) to detect (109) a potential collision hazard and to trigger (110) a security function upon detection (109) of a potential risk of collision.

Description

The invention relates to a method and a device for collision prevention between an industrial truck and at least one collision partner.

State of the art

Industrial trucks, especially forklifts, represent a not to be underestimated risk for other vehicles and people in their vicinity. This is particularly due to the great freedom of movement and dynamics and the relatively high speeds of forklifts. The risk also contributes to the partially automatic guidance of industrial trucks. Collisions with persons are predominantly among the accidents with forklifts and are associated with significant injuries of the persons concerned.

There are systems on the market which define a protective field around an industrial truck, with a warning being given when a person enters the protective field.

In the context of these systems, however, the protective fields are rigidly defined. The systems can not differentiate between different collision partners who are close to the truck. In this case, collision partners who are, for example, in the direction of travel directly in front of the truck and move very fast, a much higher risk of collision is as a collision partner, where the truck is expected to pass, since they are located laterally to the truck.

DESCRIPTION OF THE INVENTION: Problem, Solution, Advantages

It is an object of the present invention to improve a method and a device for collision prevention between an industrial truck and at least one collision partner in such a way that the method is able to distinguish collision partners equidistant from the collision risk due to the actual collision risk and thus evaluate the collision risk differently ,

The above object is achieved by the inventive method for collision prevention between an industrial truck and at least one collision partner.

The method comprises recognizing at least one collision partner within an observation field around the industrial truck, determining an approach speed to each detected collision partner, defining a protection length for each detected collision partner depending on the determined approach speed to the respective collision partner, determining a distance to each detected collision partner, comparing the distance with the guard length for each detected collision partner to detect a potential collision hazard, and triggering a safety function to detect a potential collision hazard.

Under a truck is in particular a subsidy to understand that its design is characterized in that it runs with wheels on the floor and freely steerable, set up for transporting, pulling and / or pushing loads and intended for operational use. The term "industrial truck" especially includes driverless transport vehicles, such as robots. The truck is in particular a forklift.

By the term "collision partner" is meant, in particular, a partner with which potentially a collision can take place in the future and thus a collision should be avoided. The collision partner is in particular a person. Furthermore, the collision partner may be another industrial truck.

The observation field defines an area around the truck in which collision partners can be detected. The observation field is in particular formed in a circle around the industrial truck, wherein the industrial truck is arranged in the center of the circle. In other words, the observation field includes the same radius in all directions from the truck.

An approach speed to each detected collision partner is determined. By the term "determination" is meant in particular a measurement. In particular, several distance measurements are performed for each detected collision partner. Due to the time difference between different distance measurements and the change in the respective distance between the truck and the collision partner, an approach speed can be determined. In other words, the approach speed is the relative speed between the truck and the collision partner. Since collision partners can move differently in comparison to the truck, the approach speed is individual for the respective collision partner. For example, the relative speed to a collision partner, which is located in the direct direction of travel of the truck, greater than to a collision partner, which is rather laterally from the truck, even if both Collision partners have the same own speed.

Depending on the calculated approach speed to the respective collision partner, a protection length is defined. If the respective approach speed is greater, the respective protection length is defined longer. If the respective approach speed is lower, the guard length is defined smaller. The method is thus able to assess collision partners differently with regard to a risk of collision, based on what the approach speed between the industrial truck and the collision partner is. Therefore, the method can detect which collision partner could potentially potentially get in the way in the direction of travel and on which collision partner the truck is likely to pass.

The method comprises determining a distance to each detected collision partner and comparing this determined distance with the respective guard length in order to determine a potential risk of collision. Furthermore, the method preferably includes the detection of a potential risk of collision. Determining a distance to each detected collision partner is not a distance that was previously necessary to determine an approach speed of the respective collision partners. In other words, the approach speed to each detected collision partner is determined on the basis of distance measurements. As soon as an approach speed has been determined and a protection length has been defined accordingly, a further distance is determined and compared with the protection length. In particular, the distance is to be understood as being parallel to a horizontal.

If a collision hazard is detected, a safety function is triggered. By the term "safety function" is meant in particular a function of the industrial truck and / or of the collision partner, whereby a failure of this function can lead to an immediate increase in the risk of a collision. A safety function consists for example in the complete braking or reducing the speed, for example, to a certain speed of the truck and / or the at least one collision partner. Furthermore, the safety function may include braking to a standstill and / or reducing the speed of the truck and the collision partner or only one of the two.

Furthermore, the safety function may include the output of a warning, for example acoustically and / or optically. Thus, an individual protection length is assigned to each collision partner as a function of its individual approach speed and this is compared by means of distance measurements with the respectively currently determined distance.

In particular, a risk of collision is then determined and a safety function is triggered if it turns out during the comparison that the distance is smaller than the protection length. If the respective collision partner and the truck come too close, a collision is avoided by triggering a safety function. However, due to the determination of the approach speed and the definition of a protection length based thereon, "coming too close" is individually adapted to the respective collision partner. The detection of a collision hazard is thus much more accurate.

In particular, a potential risk of collision is determined and a safety function is triggered if the truck's speed is not equal to 0, i. the truck is not at a standstill and / or the truck is moving towards the collision partner. This is to be understood in particular that the truck does not move away from the collision partner. As soon as the speed vector of the industrial truck comprises a component which is directed towards the collision partner, the industrial truck preferably moves towards the collision partner. If the velocity vector can not be subdivided into components, with one aimed at the collision partner, the truck does not move towards the collision partner. In particular, the method may include determining a speed of the industrial truck, for example by means of corresponding sensors on a wheel of a truck, for example an encoder.

Preferably, on the one hand, it is determined by comparing the distance with the guard length how close the collision partner is to the industrial truck, in particular in comparison to an individual guard length. If the distance is shorter than the guard length, another condition for triggering a safety function could be that the truck's speed is not equal to zero. This avoids that a safety function is already triggered when the truck and the collision partner get too close, but the truck does not move at all and thus from the outset a collision is ruled out. Further, additionally or alternatively, another condition may be that the truck is moving towards the collision partner.

In particular, the guard length is defined based on a braking distance, wherein the braking distance in Depending on the approach speed is determined. In particular, each approach speed can be assigned to a previously determined braking distance. The braking distance can, for example, be calculated on the basis of the approach speed or be taken from a previously defined look-up table in which certain braking distances were assigned to specific approach speeds. The term "braking distance" is here in particular not to be understood that it depends solely on the speed of the truck, but in the determination of the braking path consciously flow the speed of the truck and that of the respective collision partner. Thus, the braking distance and thus the guard length is tuned individually to the various collision partners, the braking distance is therefore determined on the basis of the approach speed.

In particular, the method includes the determination of the braking distance, either by calculation and / or by looking up in a corresponding table. The protection length corresponds in particular to the braking distance plus a safety impact, which ensures that a complete braking within the protection length can be ensured in each case. In particular, the protective length corresponds to at least 1.1 times, preferably 1.2 times, in particular at least 1.3 times the braking distance. Further preferably, the guard length corresponds to at most 2 times, in particular 1.8 times, further preferably at most 1.4 times, the braking distance.

The method comprises, in particular, the recognition of all collision partners located within the observation field. In particular, the at least one collision partner has a transmitting and / or receiving unit for transmitting and / or receiving signals. Preferably, the method comprises the assignment of at least one, in particular exactly one, transmitting and / or receiving unit per truck and / or collision partner. The transmitting and / or receiving units are arranged on the industrial truck and / or the respective collision partner.

In particular, the method comprises recognizing all collision partners located within the observation field, which have a transmitting and / or receiving unit. Furthermore, the truck preferably comprises a transmitting and / or receiving unit for transmitting or receiving the signals. The transmitting and / or receiving unit is above all a transponder and / or an antenna. In particular, the transmitting and / or receiving unit, which is arranged on the truck, designed as an antenna, while the transmitting and / or receiving units, which are arranged at the respective collision partners, represent transponder. In this case, a transponder and an antenna can have the same functions.

In determining the distance between the industrial truck and the at least one collision partner, in particular the horizontal component of the attachment position of the respective transmitting and / or receiving units on the industrial truck and / or the at least one collision partner is taken into account. By taking into account the horizontal position, it is ensured that the determined distances (in comparison to the direct measured distances) are aligned in a horizontal plane.

The signals are, in particular, electromagnetic pulses. A transmitting and / or receiving unit is designed to transmit and / or to receive corresponding signals. In particular, the transmitting and / or receiving unit is an RFID transponder, while the antenna is preferably an RF antenna. Furthermore, the transmitting and / or receiving unit can be designed to communicate via radio. The transmitting and / or receiving units are in particular designed to communicate directly with one another and / or via a central communication unit.

On the basis of the signals, distances to the collision partners can be determined by transit time measurements, and thus the approach speeds of the collision partners and of the industrial truck can be determined. In particular, the method uses for this a radio measurement technique, especially a Nahbereichsfunktechnik. This means that radio signals are sent and received between the truck and the collision partners to determine the running time and thus the distance. Above all, the UWB (ultra wideband) is used.

In particular, the signal comprises a corresponding identification mark, above all ID, so that the industrial truck and / or a central communication unit can distinguish the signals of different collision partners from one another. It is thus possible in a simple manner to determine the distance to different collision partners by evaluating signals of the same collision partner that are different in time. An assignment of a signal to a specific collision partner is no longer necessary because of the already contained in the signal tag.

Advantageously, the distance becomes too every identified collision partner regularly, in particular continuously determined. The last determined distance is also called the current distance. Furthermore, the approach speed to each identified collision partner is determined regularly, in particular continuously. The last determined approach speed is also called the current approach speed. Above all, the protection length of each identified collision partner is adjusted dynamically depending on the respective, current approach speed.

In other words, the distance to each detected collision partner is monitored by being determined regularly, in particular continuously. On the basis of the currently determined distance, the approach speed can also be determined regularly. Thus, the approach speed is also monitored. On the basis of the current approach speed, the protection length can thus be dynamically adjusted accordingly. Advantageously, to determine a potential risk of collision, the current distance with the current protection length, namely the last defined protection length compared. The distance to be compared was determined later than the distances that contributed to the determination of the current approach speed and thus to the definition of the protection length. Thus, in each case the current distance is compared with the current protection length, the actual distance after the comparison being included in the dynamic adaptation of the protection length, so that after completion of the comparison the protection length is dynamically adjusted and available for the comparison for the next determined distance ,

Preferably, the guard length defines a protective field. Each individual protection length for each collision partner thus defines an individual protective field for each collision partner. The protective field is defined in particular as a circle around the industrial truck, wherein the industrial truck is arranged in the center of the circle and wherein the protective length forms the radius of the circle. For each collision partner a separate protective field is defined, which are arranged concentrically to each other. If the respective collision partner now penetrates into its own protective field and, if appropriate, other conditions exist, for example with regard to the speed and / or direction of movement of the industrial truck, a risk of collision can be ascertained. The intrusion of one collision partner into another protective field, i. in a protective field of another collision partner irrelevant, since the protective field of another collision partner for the risk of collision this collision partner has no relevance by the individual definition of the protection length and thus the protective field. Thus, false alarms are actively avoided, as a collision risk is really only detected if a collision partner is too close to the truck depending on its approach speed.

In particular, the method does not include a step in which the environment of, for example, an industrial truck and / or a collision partner, in particular by means of a laser scanner or a camera system, is scanned.

The term "scanning" is understood to mean, above all, a transmission of a signal which is reflected back and received again with additional information.

In particular, the checking of the presence of detected and / or newly added collision partners in the observation field comprises. Above all, newly added collision partners who had previously been outside the observation field and are now within are recognized.

In a further aspect, the invention comprises a device for collision prevention between an industrial truck and at least one collision partner, wherein the device is designed for carrying out a method described above. The device comprises a receiving and / or transmitting unit for the industrial truck described above and a corresponding transmitting and / or receiving unit for the at least one collision partner. In particular, all collision partners, especially persons, within the observation field include a corresponding transmitting and / or receiving unit.

Advantageously, the device further comprises an evaluation unit, which is designed to detect at least one and / or all collision partners within an observation field, to determine their approach speeds, to define the guard lengths, to determine the distances to each detected collision partner, the determined distances with the corresponding protection lengths to compare and / or a potential collision hazard. Furthermore, the evaluation unit is designed to check the presence of detected and / or newly added collision partners and / or to adapt the protection length dynamically for each detected collision partner.

The device is a safety supplement system, in particular safety system, according to the Machinery Directive.

The device may further comprise a stationary communication unit, which is designed for communication with the transmitting and / or receiving units. In particular, the device does not comprise a laser scanner for scanning the surroundings, for example an industrial truck and / or a collision partner.

list of figures

• 1 ein Verfahrensschema eines erfindungsgemäßen Verfahrens;
• 2 eine perspektivische Ansicht eines Flurförderzeuges sowie zweier Kollisionspartner umfassend eine erfindungsgemäße Vorrichtung;
• 3 eine Draufsicht auf ein Flurförderzeug sowie zwei Kollisionspartner umfassend eine erfindungsgemäße Vorrichtung; und
• 4 eine Draufsicht auf das Flurförderzeug sowie die zwei Kollisionspartner umfassend eine erfindungsgemäße Vorrichtung nach 3 zu einem späteren Zeitpunkt.

They show schematically:

• 1 a process scheme of a method according to the invention;
• 2 a perspective view of a truck and two collision partners comprising a device according to the invention;
• 3 a plan view of an industrial truck and two collision partners comprising a device according to the invention; and
• 4 a plan view of the truck and the two collision partners comprising a device according to the invention according to 3 at a later time.

Preferred embodiments of the invention

1 shows a process scheme of a method according to the invention ( 100 ) for collision prevention between an industrial truck ( 11 ) and a collision partner ( 12 ).

The procedure ( 100 ) comprises recognizing ( 101 ) at least one collision partner ( 12 ) within an observation field ( 13 ) around the truck ( 11 ). In particular, the method comprises 100 ) the recognition ( 102 ) of all collision partners ( 12 ) within the field of observation ( 13 ).

Furthermore, the method comprises 100 ) determining ( 103 ) an approach speed to each detected collision partner ( 12 ). Depending on the determined approach speed to the respective collision partner ( 12 ) a protection length ( eighteen ) for each detected collision partner ( 12 ) Are defined ( 104 ).

Determining ( 103 ) an approach speed to the respective collision partners ( 12 ) takes place in particular on the basis of distance measurements to the collision partners ( 12 ) at different previous times. After recognizing ( 101 ) thus preferably at least two distance measurements are made to the detected collision partners ( 12 ), so that an approximate speed can be determined from these measured data ( 103 ).

It is added to each identified collision partner ( 12 ) a distance ( 19 ) ( 107 ), with the protection length ( eighteen ) for each detected collision partner ( 12 ) is compared ( 108 ) to detect a potential collision hazard. If a potential collision hazard is detected ( 109 ), a safety function is triggered ( 110 ).

The procedure ( 100 ) advantageously further comprises checking ( 105 ) the presence of detected and / or newly added collision partners ( 12 ) in the observation field ( 13 ). In particular, newly added collision partners ( 12 ) (106). For newly added collision partners ( 12 ), an approach speed is preferably determined in each case ( 103 ) and a protection length ( eighteen ) Are defined ( 104 ).

Furthermore, the method ( 100 ) determining ( 111 ) a current approach speed to each collision partner ( 12 ) based on the currently determined distance ( 19 ). Preferably, the method comprises 100 ) the dynamic adaptation ( 112 ) the protection length ( eighteen ) to each detected collision partner ( 12 ) depending on the current approach speed to the respective collision partner ( 12 ).

Advantageously, the method steps 105 to 112 regularly repeated, in particular continuously. Above all, preferably the distance ( 19 ) and / or the approach speed to each detected collision partner ( 12 ) Regemäßig, advantageously continuously determined.

2 represents a perspective view of an industrial truck ( 11 ) and two collision partners ( 12 ) comprising a device according to the invention ( 10 ).

In 2 is an industrial truck ( 11 ), a first collision partner ( 12a ) and a second collision partner ( 12b to see). The first collision partner ( 12a ) is closer to the truck ( 11 ) as the second collision partner ( 12b ). Both collision partners ( 12 ) are each provided with a transmitting and / or receiving unit ( 15 ), namely a transponder ( 16 ), while the truck ( 11 ) an antenna ( 17 ). The antenna ( 17 ) is in an upper area of the truck ( 11 ) arranged.

The distances ( 19 ) between the truck ( 11 ) and the two collision partners ( 12 ). For this the measured distance ( 20 ) between the antenna ( 17 ) and the transponders ( 16 ), in detail the first measured distance ( 20a ) and the second measured distance ( 20b ). These measured distances ( 20 ) do not represent distances which are arranged parallel to a horizontal, but in them also the height of the mounting position of the antenna ( 17 ) as well as the transponder ( 16 ) with a. The real distance ( 19 ), ie the actual distance in the horizontal direction, is determined by the measured distances ( 20 ) determined by the information about the height of the mounting positions of the transmitting and / or receiving units ( 15 ) with in the Calculation is included. Thus, the first distance ( 19a ) and the second distance ( 19b ), which are horizontally aligned.

3 shows a plan view of an industrial truck ( 11 ) and two collision partners ( 12 ) comprising a device according to the invention ( 10 ).

The truck ( 11 ) moves in the direction of travel ( 14 ). To the industrial truck ( 11 ) is an observation field ( 13 ) arranged. The observation field ( 13 ) has in particular a circular shape, wherein the industrial truck ( 11 ) is in the middle. The observation field ( 13 ) is characterized by the fact that in this collision partner ( 12 ) connected to a transmitting and / or receiving unit ( 15 ) are equipped by a corresponding transmitting and / or receiving unit ( 15 ) of the truck ( 11 ) can be detected. At the transmitting and / or receiving unit ( 15 ) of the truck ( 11 ) is in particular an antenna ( 17 ), while at the transmitting and / or receiving units ( 15 ) the collision partner ( 12 ) preferably transponder ( 16 ).

In the observation field ( 13 ) there are two collision partners ( 12 ), which are persons, a first collision partner ( 12a ) and a second collision partner ( 12b ).

By means of the method according to the invention ( 100 ) is a respective approach speed to the two collision partners ( 12 ). In the present example, the approach speed is the second collision partner ( 12b ) greater than the first collision partner ( 12a ), since the second collision partner ( 12b ) in this example faster on the truck ( 11 ). Based on the approach speed, guard lengths ( eighteen ) for the collision partners ( 12 ) Are defined. Since the approach speed to the second collision partner ( 12b ) is greater, the corresponding second protection length ( 18b ), the second collision partner ( 12b ) is assigned, larger. The second protection length ( 18b ) defines a second protective field ( 21b ) whose radius is defined by the second protection length ( 18b ) is determined. In contrast, due to the smaller approach speed, the first collision partner ( 12a ) the corresponding protection length ( 18a ) and thus also the first protective field ( 21a ).

4 shows the top view of the truck ( 11 ) and the two collision partners ( 12 ) comprising a device according to the invention ( 10 ) the 3 at a later time.

The approach speeds of the collision partners ( 12 ) to the truck ( 11 ) have not changed so that the corresponding protection lengths ( eighteen ) and protection areas ( 21 ) stayed the same. The corresponding protection areas ( 21 ) move with the truck ( 11 ) in the direction of travel ( 14 ). The movement is now the second collision partner ( 12b ) within its assigned second protection area ( 21b ). According to the invention, a distance ( 19 ) to the collision partners ( 12 ). The second distance ( 19b ) to the second collision partner ( 12b ) is now smaller than the corresponding protection length ( 18b ). In response, a safety function is triggered.

The first distance ( 19a ) to the first collision partner ( 12a ) is larger than the first protection length ( 18a ). Therefore, with regard to the first collision partner ( 12a ) no potential collision hazard. Also the fact that the first distance ( 19a ) is smaller than the second protection length ( 18b ) triggers no safety function because the determined distances ( 19 ) only with the respective assigned protection lengths ( eighteen ).

Further, at the time, in 4 another collision partner ( 12 ), a third collision partner ( 12c ), into the observation field ( 13 ) and was recognized by the method.

The third collision partner ( 12c ) is in the direction of travel ( 14 ) behind the truck ( 11 ). Due to the fact that the third collision partner ( 12c ) behind the truck ( 11 ), the assessment of a risk of collision can be defined differently. Does the third collision partner ( 12c ) faster on the truck ( 11 ) to as the industrial truck ( 11 ) in the direction of travel ( 14 ), the approach speed is positive and the third collision partner ( 12c ), a third protective field ( 21c ) with a third protection length ( 18c ). However, it can be defined that no danger of collision is detected, even if the determined distance to the third collision partner ( 12c ) smaller than the corresponding third protection length ( 18c ), since the third collision partner ( 12c ) on the truck ( 11 ), but the truck moves away. Should the direction of travel ( 14 ) of the truck ( 11 ), so that the truck ( 11 ) no longer from the third collision partner ( 12c ), but moving towards it, the determination of a risk of collision could be defined in such a way that in such a case, when the third protection length is not reached ( 18c ) by the determined distance to the third collision partner ( 12c ) a collision hazard is detected.

Furthermore, in 4 the speed vectors of the truck ( 11 ) in the direction of travel ( 14 ) and in the direction of the different collision partners. It is the velocity vector ( 22a ) in the direction of the first collision partner ( 12a ), the velocity vector ( 22b ) in the direction of the second collision partner ( 12b ), the velocity vector ( 22c ) in the direction of the third collision partner ( 12c ), which is negative because the truck ( 11 ) from the third collision partner ( 12c ) and the velocity vector ( 22d ) in the direction of travel ( 14 ). It can be clearly seen how the velocity vector becomes smaller, the more the direction of the direction of travel ( 14 ) deviates.

LIST OF REFERENCE NUMBERS

100

inventive method

101

Detecting at least one collision partner within an observation field around the truck

102

Recognition of all collision partners within an observation field around the truck

103

Determining a speed of approach to each detected collision partner

104

Defining a protection length for each detected collision partner as a function of the determined approach speed to the respective collision partner

105

Check the presence of detected and / or newly added collision partners in the observation field

106

Recognize newly added collision partner

107

Determining a distance to each detected collision partner

108

Comparison of the distance with the guard length for each detected collision partner for the detection of a potential risk of collision

109

Identify a potential collision hazard

110

Triggering a security function

111

Determine a current approach speed to each detected collision partner

112

Dynamic adaptation of the protection length for each detected collision partner as a function of the current approach speed to the respective collision partner

10

device

11

Truck

12

collision partners

12a

first collision partner

12b

second collision partner

12c

third collision partner

13

observation field

14

direction of travel

15

Transmitting and / or receiving unit

16

transponder

17

antenna

18

protection length

18a

first protection length

18b

second protection length

18c

third protection length

19

distance

19a

first distance

19b

second distance

20

measured distance

20a

first measured distance

20b

second measured distance

21

protection field

21a

first protective field

21b

second protective field

21c

third protective field

22a

Velocity vector in the direction of the first collision partner

22b

Velocity vector in the direction of the second collision partner

22c

Velocity vector in the direction of the third collision partner

22d

Speed vector in the direction of travel

Claims (14)

Method (100) for collision prevention between an industrial truck (11) and at least one collision partner (12), characterized in that the method (100) comprises the following steps: detecting (101) at least one collision partner (12) within an observation field (13 ) about the truck (11), • determining (103) an approach speed to each detected collision partner (12), • defining (104) a guard length (18) for each detected collision partner (12) in dependence of determining the approach speed to the respective collision partner (12), • determining (107) a distance (19) to each detected collision partner (12), • comparing (108) the distance (19) with the guard length (18) for each detected collision partner (12) determining (109) a potential collision hazard, and • triggering (110) a safety function upon detection (109) of a potential collision hazard. Method (100) according to Claim 1 , characterized in that a potential risk of collision is determined (109) and a safety function is triggered (110) if the distance (19) is smaller than the guard length (18). Method (100) according to one of Claims 1 or 2 , characterized in that a potential risk of collision is detected (109) and a safety function is triggered (110) if the speed of the truck (11) is not equal to zero and / or the truck (11) moves toward the collision partner (12). Method (100) according to one of the preceding claims, characterized in that the protective length (18) is defined on the basis of a braking distance, wherein the braking distance is determined as a function of the approaching speed. Method (100) according to one of the preceding claims, characterized in that the method (100) comprises the detection (102) of all collision partners (12) located within the observation field (13). Method (100) according to one of the preceding claims, characterized in that the at least one collision partner (12) has a transmitting and / or receiving unit (15) for transmitting and / or receiving signals. Method (100) according to one of the preceding claims, characterized in that the industrial truck (11) has a transmitting and / or receiving unit (15) for transmitting and / or receiving signals. Method (100) according to one of Claims 6 or 7 , characterized in that the transmitting and / or receiving unit (15) as a transponder (16) and / or as an antenna (17) is formed. Method (100) according to one of the preceding claims, characterized in that the distance (19) to each detected collision partner (12) is determined regularly, in particular continuously. Method (100) according to one of the preceding claims, characterized in that the approaching speed to each detected collision partner (12) is determined regularly, in particular continuously. Method (100) according to Claim 10 , characterized in that the guard length (18) of each detected collision partner (12) is dynamically adjusted (112) as a function of the respective actual approach speed. Method (100) according to one of the preceding claims, characterized in that the protective length (18) defines a protective field (21). Method (100) according to one of Claims 9 or 10 and one of the Claims 11 and 12 , characterized in that for detecting (109) a potential risk of collision, the current distance is compared with the current protection length. Device (10) for collision prevention between an industrial truck (11) and a collision partner (12), characterized in that the device (10) for carrying out a method (100) according to one of Claims 1 to 13 is trained.

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