DE102019215169A1 - Industrial truck, set up for driverless, autonomous operation - Google Patents

Abstract

The invention relates to an industrial truck (1), set up for driverless, autonomous operation, having a loading area (1.1) for a load (2) to be transported, comprising at least: a control system (3) that controls the industrial truck (1) and steers - an evaluation unit (4) which generates a signal to stop the industrial truck (1), a detector device (5) being connected to the control system (3) for detecting the arrangement of the load (2) in the loading area (1.1) and wherein the detector device (5) comprises a redundant sensor system (7).

Description

The present invention relates to a driverless, autonomously operating industrial truck (Automated Guided Vehicle, AGV) for a load to be transported. In particular, the invention finds application in a robotic vehicle for the transport of loads. Lifting industrial trucks and non-stacking pallet trucks and combinations thereof are also included.

As automation technology advances, the handling of loads is becoming increasingly important.

If an industrial truck lifts the load to be transported for transport, it must be ensured that the load remains in the specified position during transport and that the load does not slip in an unsafe condition. Slipping of the load can be prevented, for example, by 1) a form-fitting receiving device (locking), which is activated after charging and before the vehicle is set in motion, or 2) a non-positive receiving device.

Variant 1) can completely prevent slipping (if correctly designed). Variant 2) is based on the normal force of the load and therefore involves uncertainties due to the dynamic forces that cannot be foreseen in all driving situations. So z. B. due to bumps or at the transition of a slope in a plane an inertial force that counteracts the normal force. If it is sufficiently large to cancel the normal force or at least to reduce it to a significant extent, the load can move out of the intended position.

Based on this, the object of the present invention is to create an industrial truck, set up for driverless, autonomously operating operation, which alleviates or even avoids the disadvantages mentioned. In particular, it should be made possible in a structurally simple manner to prevent an unsafe state caused by the transported goods slipping. This should also be ensured in particular when the goods to be transported are stored on rollers. In addition, the movement of the industrial truck should be safely stopped in the event of slipping.

These objects are achieved with an industrial truck according to the independently formulated claim. Further refinements of the invention are specified in the dependent claims. It should be pointed out that the description, in particular in connection with the figures, provides further details and developments of the invention which can be combined with the features from the patent claims.

• - ein Steuerungssystem, das das Flurförderzeug steuert und lenkt,
• - eine Auswerteeinheit, die ein Signal zum Anhalten des Flurförderzeugs erzeugt, wobei eine Detektoreinrichtung zur Erkennung der Anordnung der Last im Ladebereich an das Steuerungssystem angeschlossen ist und wobei die Detektoreinrichtung ein redundantes Sensorsystem umfasst.

Contributing to this is an industrial truck that is set up for driverless, autonomous operation, has a loading area for a load to be transported and comprises at least the following:

• - a control system that controls and steers the industrial truck,
• an evaluation unit which generates a signal to stop the industrial truck, a detector device for detecting the arrangement of the load in the loading area being connected to the control system and the detector device comprising a redundant sensor system.

The industrial truck presented here has the advantage that the position of the load is continuously monitored, movement of the load can be detected and the vehicle can be safely stopped so that there is no danger to bystanders. In particular, increased safety is achieved through additional monitoring of the load position. Further advantages consist of reduced costs and eliminated wear (in particular due to the omission of the mechanical components and the associated actuators for anchoring the load and the (new) use of existing sensors) with the same level of security compared to the known form-fitting receiving device.

A driverless industrial truck can be a power-driven vehicle, possibly including any trailer, which is intended to drive independently. For this purpose, the industrial truck can interact with a guidance system in the ground or in the environment, which specifies the routes.

“Load” means an object to be handled, including its mass, dimensions, condition and / or arrangement. The load can (only) consist of one load. The load can also be the load and a transport device for the load, eg. B. a trolley, a pallet, a trolley, etc. include. “Load handling” that can be carried out by the industrial truck is understood to mean, in particular, lifting, lowering, load transfer and / or load handling.

The content of the control system is an automatic device which controls the industrial truck and its associated devices (eg activated / deactivated) and (possibly monitored by sensors) steers. The system of the driverless industrial truck includes the control system, which can be part of the industrial truck and / or separate from it. The Control system can comprise a computing unit which is provided in or on the industrial truck.

The evaluation unit is connected to a sensor system, preferably electrically and in a data-conducting manner, and is set up to process its signals. The evaluation unit is set up in particular to carry out an analysis of the data from the sensor system of the industrial truck, so that in particular the load can be clearly recorded or determined with regard to its location relative to the loading area of the industrial truck. The position determined in the evaluation unit can be compared and / or influenced with predetermined (e.g. stored and / or set) parameters, in which case a control signal is also transmitted to the controller and the operation of the industrial truck can be influenced by the evaluation unit . The evaluation unit can be a separate (electronic) unit, but it is also possible that the evaluation unit is part of the control system for controlling the industrial truck itself. The (at least) one data-conducting connection between the evaluation unit and the control unit and the sensor system can be implemented with a cable or wirelessly.

The detector device is set up to generate a signal which is representative of the loading condition and / or a change in the loading condition. This can be interpreted by the evaluation unit and initiate an instruction to the control system, by means of which the truck can be stopped by means of a braking system under the specified operating conditions, in particular before fixed parts of the truck and / or the load in particular (partially) leaves the loading area and / or strike a person. The detector device for detecting the arrangement of the load, in particular slipping of the load and / or for positioning the load, is connected to the evaluation unit and / or control device.

The detector device comprises at least one redundant sensor system which is set up fail-safe. “Redundant” in this context means in particular that at least 2 (independent and / or possibly different) detection mechanisms or sensors are present. These are set up in particular so that they can carry out their measuring function or signaling completely and independently of one another.

The control system preferably comprises a control unit for the desired direction of travel and the speed, a control unit for the movement and a control unit for the safety of the industrial truck. A first control unit (Robot Control Unit, RCU), a second control unit (Motion Control Unit, MCU) and a third control unit (Safety Control Unit, SCU) are preferably part of the control system.

The sensor system advantageously comprises at least one inductive sensor. The inductive sensor can be designed as an inductive proximity switch or as an inductive displacement sensor.

The inductive sensor is preferably a proximity sensor. The inductive sensor is expediently arranged at the rear end of the industrial truck in the border area or near the loading area. The inductive sensor can detect a load on the truck, a dolly on the truck or a load on the truck.

The inductive sensor preferably has an inherent safety function (so-called “safe” sensor). The inductive safety sensor set up in this way can, for. B. be protected against cable breakage or enable continuous checking of its functions. This sensor can thus comprise at least 2 measuring lines and / or sensor cells, so that there is protection against failure.

A combination of a "simple" inductive sensor without inherent safety function and a laser scanner is advantageous. Laser scanners scan a specified area of the environment with laser light. A laser beam is emitted by the scanner, which is then reflected again by the surroundings, an object or an obstacle and is picked up again by receiving optics. The laser can be deflected using a deflecting mirror that is pivoted. The transit time of the laser from the scanner until it is received again is determined and evaluated, whereby it is possible to infer a distance to an obstacle in the scanning area. A type of “image” can also be generated showing the relative position of several detected objects to one another. This also enables a more complex analysis of the environment. The sensor system can be set up here in such a way that the inductive sensor (partially) monitors the charging area and the laser scanner (partially) monitors the adjacent surrounding area. A “redundant” system is also set up in this way.

The laser scanner is preferably arranged on the rear part of the industrial truck and, if necessary, oriented towards the reversing area.

The inductive sensor with safety function or the combination of inductive sensor without safety function and laser scanner are expediently connected to the third control unit (SCU).

The second control unit and the third control unit are preferably set up to recognize a slipped load and to stop the industrial truck.

The evaluation unit is advantageously integrated into the control system.

The load preferably comprises the load and / or a trolley for the load.

With the industrial truck presented here, a slipped load is detected by the travel control and safety control and causes the vehicle to stop. Option 1 provides for a “safe” inductive proximity sensor on the back of the loading area or at the edge of the loading area. Option 2 consists in evaluating a sensor combination of a “simple” inductive proximity sensor on the back of the loading area or at the edge of the loading area and the rear laser scanner.

The industrial truck can accordingly also be designed with a system for data processing, comprising means for executing the aforementioned steps of the method with the redundant control system. In particular, the system is set up to determine a change in the location and / or position of the load relative to the loading area by means of the redundant control system, in particular using the evaluation unit, with the (immediate) stopping of the truck when a (predeterminable) impermissible change is detected becomes.

As a precaution, it should be noted that the designation of elements with numerals (“first”, “second”, ...) is only used to differentiate and does not have to specify any dependency or sequence of the elements. With regard to the sensors, this means, for example, that their attachment (stationary, traveling) and / or location (on a carrier, gripper, etc.) can be freely selected or according to the technical conditions, regardless of the designation.

• 1: Draufsicht auf ein fahrerloses, autonom agierendes Flurförderzeug mit einem Steuerungssystem und einer Detektoreinrichtung;
• 2: Blockschaltbild mit dem Steuerungssystem, an das ein induktiver Sensor, ein Laserscanner, eine Auswerteeinheit, ein erster Motor, ein zweiter Motor und ein Sollwertspeicher angeschlossen sind;
• 3: Seitenansicht auf das Flurförderzeug gemäß 1 mit beladener Last und einem induktiven Sensor mit inhärenter Sicherheitsfunktion; und
• 4: eine Seitenansicht auf das Flurförderzeug wie 3, jedoch mit einem induktiven Sensor ohne inhärente Sicherheitsfunktion und einem Laserscanner.

The invention and the technical environment are explained in more detail below with reference to figures. The same components are identified by the same reference numerals. The representations are schematic and are not intended to illustrate proportions. The explanations given with reference to individual details of a figure can be extracted and freely combined with facts from other figures or the above description, unless something else is mandatory for a person skilled in the art or such a combination is explicitly prohibited. They show schematically:

• 1 : Top view of a driverless, autonomously operating industrial truck with a control system and a detector device;
• 2 : Block diagram with the control system to which an inductive sensor, a laser scanner, an evaluation unit, a first motor, a second motor and a setpoint memory are connected;
• 3 : Side view of the truck according to 1 with loaded load and an inductive sensor with inherent safety function; and
• 4th : a side view of the truck like 3 , but with an inductive sensor without an inherent safety function and a laser scanner.

1 shows a top view of a driverless, autonomously operating industrial truck 1 with a control system 3 , as well as a redundant sensor system 7th comprising a load sensor 6th (Position sensor) and a laser scanner 8th .

The industrial truck presented here 1 has a loading area 1.1 for a load to be transported 2 (see also 3 and 4th ) and includes at least the control system 3 that controls and steers the truck, and an evaluation unit 4th (see also 2 ), which give a signal to stop the truck 1 generated or can cause. The detector device 5 (see also 2 ) to recognize the arrangement of the load 2 is to the control system 3 connected, the detector device 5 as a load sensor 6th an inductive sensor and a laser scanner 8th includes. The control system 3 comprises a first control unit 9 for the desired direction of travel and the speed, a second control unit 10 for movement and a third control unit 11 for the safety of the industrial truck 1 . With 12th is a first motor for the movement of the industrial truck 1 and at 13 a second motor for adjusting the height of a lifting and lowering device 14th (see 2 ) designated. With 15th is a first encoder (target speed) and with 16 is a second encoder, z. B. SIL-2 encoder.

• 1) Erkennen des Verlassens der festgelegten Position des Ladeguts 21.
• 2) Sicheres (unmittelbares bzw. automatisches) Stillsetzen des Flurförderzeugs 1.

Preventing the unsafe condition is achieved through

• 1) Detection of leaving the defined position of the load 21 .
• 2) Safe (immediate or automatic) stopping of the industrial truck 1 .

1. a) Die Position der Last 2 wird mittels eines sicheren Sensors erfasst, der von einer sicheren Steuereinrichtung überwacht.
2. b) Die Position der Last 2 wird mittels einer Kombination aus diversitären, nicht sicheren Sensoren erfasst, die von einer sicheren Steuereinrichtung überwacht werden. Dazu können z. B. ein induktiver Schalter sowie ein rückwärtiger Laserscanner 8 verwendet werden. Im konkreten Anwendungsfall würde eine verrutschte Last 2 durch mechanische Führung zwangsweise in die Warn- bzw. Schutzfelder des Laserscanners 8 eindringen.

The detection of leaving the specified position can be carried out using various sensor concepts:

1. a) The position of the load 2 is recorded by means of a safe sensor that is monitored by a safe control device.
2. b) The position of the load 2 is detected using a combination of diverse, non-safe sensors that are monitored by a safe control device. For this purpose z. B. an inductive switch and a rear laser scanner 8th be used. In a specific application, the load would have slipped 2 forced into the warning or protective fields of the laser scanner through mechanical guidance 8th penetration.

• 1) Die erste Steuereinheit 9 gibt die gewünschte Fahrtrichtung und die Geschwindigkeit an die zweite Steuereinheit 10.
• 2) Die zweite Steuereinheit 10 gibt die gewünschte Fahrtrichtung weiter an die dritte Steuereinheit 11, berechnet die Solldrehzahl und gibt diese an die Motoren.
• 3) Die dritte Steuereinheit 11 erkennt über einen a) sicheren induktiven Sensor oder b) unsicheren Sensor und Warn- bzw. Schutzfelder des hinteren Laserscanners 8, wenn die Last 2 verrutscht und setzt über die zweite Steuereinheit 10 die Geschwindigkeit auf v = 0 mm/s. (Die Sollgeschwindigkeit der dritten Steuereinheit 11 hat Vorrang vor der Wunschgeschwindigkeit der ersten Steuereinheit 9).

Basic flow logic:

• 1) The first control unit 9 gives the desired direction of travel and the speed to the second control unit 10 .
• 2) The second control unit 10 forwards the desired direction of travel to the third control unit 11 , calculates the target speed and sends it to the motors.
• 3) The third control unit 11 detects a) safe inductive sensor or b) unsafe sensor and warning or protective fields of the rear laser scanner 8th when the load 2 slips and sets over the second control unit 10 the speed to v = 0 mm / s. (The target speed of the third control unit 11 has priority over the desired speed of the first control unit 9 ).

2 Figure 10 illustrates a block diagram with the control system 3 for the industrial truck presented here 1 . The load sensor 6th and the laser scanner 8th are via the evaluation unit 4th to the electronic control system 3 through a data-conducting connection 17th connected. The second control unit 10 stands above the first speed sensor 15th (Target speed) with the first motor 12th in connection. The second speed sensor 16 stands with the third control unit 11 in connection. A braking system 18th is to the tax system 3 connected that a signal to the first motor 12th to stop the truck 1 can generate. The braking system 18th can also be used alone or in combination with the first engine 12th onto the truck 1 act. Furthermore is the second engine 13th for driving the lifting and lowering device 14th to the control system 3 connected. The detector device 5 can also be used to identify the positioning of the lifting and lowering unit 14th can be used. With 19th denotes a storage element.

3 shows a side view of the industrial truck 1 according to 1 with a loaded load 2 and as a load sensor 6th an inductive sensor, e.g. B. a "safe" sensor with an inherent safety function. The load sensor 6th is at the rear of the front section in front of the cargo area 1.1 of the industrial truck 1 attached and facing the load 2 aligned. Weight 2 consists of one load 21 and a trolley 22nd with which the load 21 can be transported. With 20.1 , 20.2 and 20.3 are wheels of the industrial truck 1 designated. With 23.1 and 23.2 are wheels of the transport trolley 22nd designated.

4th represents a side view of the industrial truck 1 and the load 2 according to 3 but with a load sensor 6th in the form of an inductive sensor without an inherent safety function and with a laser scanner 8th . The load sensor 6th is at the back of the cargo area 1.1 appropriate. The laser scanner 8th is at the rear of the truck 1 arranged and the laser field of view 8.1 is in the direction away from the truck 1 aligned. The load sensor 6th can in the embodiments according to 3 and 4th be an inductive "Dolly Detection" sensor (DDS).

The driverless, autonomously operating industrial truck presented here 1 (AGV) is preferably used e.g. B. in factories, warehouses, supermarkets or hospitals. Due to sensors, e.g. B. Laser scanners 8th , Load sensor 6th , inductive proximity sensors, ultrasonic sensors and / or 3D cameras, collisions - a person and / or an object - and / or disorientation are avoided. For example, pallets, boxes, shelves, individual parts or small load carriers (KLTs) are transported with or without a transport trolley 22nd ("Dolly").

List of reference symbols

1

Industrial truck

1.1

Loading area

2

load

3

Control system

4th

Evaluation unit

5

Detector device

6th

Load sensor

7th

Sensor system

8th

Laser scanner

8.1

Laser field of view

9

first control unit

10

second control unit

11

third control unit

12th

first engine

13th

second engine

14th

Lifting and lowering device

15th

first encoder

16

second rotary encoder

17th

data-conducting connection

18th

Braking system

19th

Storage element

20.1, 20.2, 20.3

Truck wheels

21

Load

22nd

Transport trolley

23.1, 23.2

Wheels of the transport trolley

A, B

Directions of movement

Claims (12)

Industrial truck (1), set up for driverless, autonomous operation, having a loading area (1.1) for a load (2) to be transported, comprising at least: - a control system (3) that controls and steers the industrial truck (1), - An evaluation unit (4) which generates a signal for stopping the industrial truck (1), wherein a detector device (5) for detecting the arrangement of the load (2) in the loading area (1.1) is connected to the control system (3) and wherein the Detector device (5) comprises a redundant sensor system (7). Industrial truck (1) Claim 1 , wherein the control system (3) comprises a control unit (9) for the desired direction of travel and the speed, a control unit (10) for the movement and a control unit (11) for the safety of the industrial truck (1). Industrial truck (1) Claim 1 or 2 , wherein the sensor system (7) comprises at least one inductive sensor. Industrial truck (1) Claim 3 , wherein the inductive sensor is a proximity sensor. Industrial truck (1) according to one of the preceding claims, wherein the inductive sensor is arranged on a rear side of the front section in front of the loading area (1.1) of the industrial truck (1). Industrial truck (1) according to one of the preceding claims, wherein the inductive sensor has an inherent safety function. Industrial truck (1) according to one of the preceding claims, wherein there is a combination of an inductive sensor without an inherent safety function and a laser scanner (8). Industrial truck (1) according to one of the preceding claims, wherein the laser scanner (8) is arranged on the rear part of the industrial truck (1). Industrial truck (1) according to one of the preceding claims, wherein the inductive sensor with safety function or the combination of inductive sensor without safety function and laser scanner (8) are connected to the third control unit (11). Industrial truck (1) according to one of the preceding claims, wherein the second control unit (10) and the third control unit (11) are set up to detect a slipped load (2) and to stop the industrial truck (1). Industrial truck (1) according to one of the preceding claims, wherein the evaluation unit (4) is integrated into the control system (3). Industrial truck (1) according to one of the preceding claims, wherein the load (2) comprises a load (21) and / or a trolley (22) for the load (21).

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