SE542070C2

SE542070C2 - Remotely-operated control system and on-board control unit

Info

Publication number: SE542070C2
Application number: SE1850043A
Authority: SE
Inventors: Göran Valfridsson; Oskar Bergqvist
Original assignee: Toyota Mat Handling Manufacturing Sweden Ab
Priority date: 2018-01-16
Filing date: 2018-01-16
Publication date: 2020-02-18
Also published as: SE1850043A1

Abstract

The present disclosure relates to a method for authentication of remote control of an industrial vehicle. The method comprises the steps of: creating (S1) a sensor data packet comprising sensor data received from the industrial vehicle and a time stamp; sending (S2) the sensor data packet to a remote control unit; receiving (S3) a command data packet from a remote control unit, comprising the time stamp and at least one operating command; determining (S4) a time delay between current time and the received time stamp; performing (S5) a time delay test by determining if the time delay is lower than a time limit; and if the time delay test is passed: controlling (S6) at least one actuator of the industrial vehicle, based on the at least one operating command. Further, the disclosure relates to an industrial vehicle (1). Further, the present disclosure relates to a remotely-operated control system comprising the on-board control unit (10) of an industrial vehicle (1) and a remote control unit (200). The disclosure also relates to a computer program and a computer-readable medium.

Description

REMOTELY-OPERATED CONTROL SYSTEM AND ON-BOARD CONTROL UNIT TECHNICAL FIELD The present disclosure relates to a remotely-operated control system. Further, the disclosure relates to an industrial vehicle. Yet further, the disclosure relates to a method for authentication of remote control of an industrial vehicle. The disclosure also relates to a computer program and a computer-readable medium.

BACKGROUND ART Various kinds of industrial vehicles are becoming increasingly autonomous. Industrial vehicles that can be both autonomous and manually controlled are referred to as semi-autonomous. In case of unexpected events it might be necessary to manually control the industrial vehicle. In such case it is often necessary to verify that control signals received by the industrial vehicle are correct.

US2017160739A1 relates to a remote-controlled system comprising, on the ground and in the vehicle, security monitoring systems suitable for approving and/or authenticating critical data and/or commands exchanged between the ground and the vehicle and also suitable for verifying the integrity of said data. It is thus possible to use, on the ground as on board the vehicle, interfaces and units with a low level of criticality at the same time as interfaces and units with the highest level of criticality.

SUMMARY OF THE DISCLOSURE The disclosure relates to a remotely-operated control system. The remotely-operated control system comprises a remote control unit, connected to an on-board control unit of an industrial vehicle via a communication link, configured to remotely control motions of the industrial vehicle via the on-board control unit, by sending command data to the on-board control unit. The on-board control unit of the industrial vehicle, connected to the remote control unit via the communication link, is configured to receive sensor data from at least one sensor of the industrial vehicle, send the received sensor data to the remote control unit, receive command data from the remote control unit, and to control the industrial vehicle based on the received command data. The on-board control unit is further configured to create a sensor data packet comprising the sensor data received from the at least one sensor and a time stamp, and to send the sensor data packet to the remote control unit. The remote control unit is further configured to receive the sensor data packet, and send a command data packet comprising the time stamp and at least one operating command. The on-board control unit is further configured to receive the command data packet, comprising the time stamp and the at least one operating command, determine a time delay between current time and the received time stamp, and, perform a time delay test by determining if the time delay is lower than a time limit. If the time delay test is passed, the on-board control unit is configured to control at least one actuator of the industrial vehicle, based on the received at least one operating command.

An advantage is that it is possible to verify if a command data packet, and thereby also the at least one operating command, is correct by checking the time delay of the time stamp. Thus, safety is increased during remote operation of the industrial vehicle.

In one example, the remote control unit is configured to add an error detection checksum to the command data packet, and the on-board control unit is configured to perform an error detection test by determining if the checksum is correct. If both the time delay test and the error detection test are passed, the on-board control unit is configured to control the industrial vehicle based on the received at least one operating command. An advantage is that it is possible to verify if operating commands are correct by checking the checksum. Thereby the safety of the industrial vehicle is further increased.

In another example, the checksum is a cyclic redundancy check, CRC, checksum, preferably a CRC-32 checksum. An advantage is CRS checksums is a well-known checksum standard for verifying if data packets are received correctly.

In a further example, the on-board control unit is configured to send a status message to the remote control unit to confirm if the on-board control unit passed the at least one test to control the industrial vehicle, or not. An advantage is that an operator of the remote control unit will be informed about if operating commands are fulfilled or not.

In a yet further example, the time limit is lower than 500 ms, preferably lower than 300 ms, more preferably lower than 150 ms, most preferably lower than 75 ms.

In another example, the industrial vehicle is an industrial forklift, an Automated Guided Vehicle, a warehouse crane or a warehouse stacker crane.

Further, the disclosure relates to an industrial vehicle comprising an on-board control unit. The on-board control unit is connected to a remote control unit via a communication link. The on-board control unit is configured to receive sensor data from at least one sensor of the industrial vehicle, send the received sensor data to a remote control unit, receive command data from a remote control unit, and to control the industrial vehicle based on the received command data packets. The on-board control unit is further configured to create a sensor data packet comprising the sensor data received from the at least one sensor and a time stamp, and to send the sensor data packet to a remote control unit. Further, the on-board control unit is configured to receive a command data packet from a remote control unit, comprising the time stamp and at least one operating command, determine a time delay between current time and the received time stamp, perform a time delay test by determining if the time delay is lower than a time limit. If the time delay test is passed, the onboard control unit is configured to control at least one actuator of the industrial vehicle, based on the received at least one operating command.

Yet further, the disclosure relates to a method for authentication, by means of an on-board control unit, of remote control of an industrial vehicle by a remote control unit. The method comprises the steps of: creating a sensor data packet comprising sensor data received from the industrial vehicle and a time stamp; sending the sensor data packet to a remote control unit; receiving a command data packet from a remote control unit, comprising the time stamp and at least one operating command; determining a time delay between current time and the received time stamp; performing a time delay test by determining if the time delay is lower than a time limit; and if the time delay test is passed: controlling at least one actuator of the industrial vehicle, based on the at least one operating command.

Additionally, the disclosure relates to a computer program comprising instructions which, when the program is executed by a control unit, cause the control unit to carry out the method. Further, the disclosure relates to a computer-readable medium comprising instructions which, when executed by a control unit, cause the control unit to carry out the method.

BRIEF DESCRIPTION OF THE DRAWINGS The disclosure will be further described with reference to the accompanying drawings: FIG. 1 shows a schematic drawing of a remotely-operated control system.

FIG. 2 illustrates a sequence of events carried out by the remotely-operated control system. FIG. 3 shows a flow chart explaining how to determine Performance Level.

FIG. 4 illustrates a flowchart of a method carried out by an on-board control unit.

FIG. 5 illustrates an alternative flowchart of a method carried out by the on-board control unit. FIG. 6 shows an example of an industrial vehicle, represented by an order picker truck.

FIG. 7 shows an example of an industrial vehicle, represented by a reach truck.

FIG. 8 shows an example of an industrial vehicle, represented by a stacker truck.

DETAILED DESCRIPTION FIG. 1 shows a schematic drawing of a remotely-operated control system. An industrial vehicle 1 comprises an on-board control unit 10. The on-board control unit 10 is connected to at least one sensor 12 and to at least one actuator 14. The on-board control unit 10 is arranged to receive sensor data 20 from the at least one sensor 12. The at least one sensor 12 may be a camera, an active sensor, such as LIDAR or LADAR, a microphone or any other sensor suitable for an industrial vehicle. Further, the on-board control unit 10 is configured to receive sensor data 20 from the at least one actuator 14. The at least one actuator 14 may be a motor, a steering mechanism 7, 7a, a load carrier 6 or a hydraulic cylinder configured to perform a hydraulic function of the industrial vehicle 1. The hydraulic cylinder may be configured to control a hydraulic system of a forklift, an order picker truck, a reach truck, or a stacker truck. Yet further, the on-board control unit 10 is configured to control the at least one actuator 14 in order to manoeuvre the industrial vehicle 1.

As shown in FIG. 2, the on-board control unit 10 is also configured create sensor data packet(s) 40 comprising the sensor data 20, received from the sensor(s) 12, and a time stamp 30. The sensor data 20 and the time stamp 30 is part of the payload of the sensor data packet. The time stamp 30 represents the time of creating the sensor data packet 40 according to the onboard control unit 10. The time of the on-board control unit 10 may be different than the correct time. Each sensor data packet 40 is a network packet, for example an IP packet, such as an IPv4 packet or an IPv6 packet, or an IPsec packet. The on-board control unit 10 is configured to send the sensor data packet(s) 40 to a remote control unit 200. The on-board control unit 10 is connected to a transceiver 16. The sensor data packet(s) 40 may be sent via the transceiver 16. In one example, the transceiver 16 is configured to send and receive data packets to another transceiver which is connected to Internet by wire. Yet further, the onboard control unit 10 is configured to receive command data packet(s) 70 from the remote control unit 200, comprising the time stamp 30 and at least one operating command 50. The command data packet(s) 70 are received via the transceiver 16. The on-board control unit 10 is also configured to determine a time delay between current time and the received time stamp 30. The received time stamp 30 may comprise the time of the on-board control unit 10 when the sensor data packet 40 was created. Alternatively, the received time stamp 30 may comprise the time of the on-board control unit 10 when the sensor data packet 40 was sent by the transceiver 16. The current time may be the time of on-board control unit 10 when the onboard control unit 10 received the command data packet(s) 70. Alternatively, current time may be the time of on-board control unit 10 when the transceiver 16 received the command data packet(s) 70. Based on the time delay between current time and the received time stamp 30, the on-board control unit 10 is configured to perform a time delay test by determining if the time delay is lower than a time limit. If the time delay test is passed, control at least one actuator 14 of the industrial vehicle 1, based on the received at least one operating command 50. Thus, the time delay test enables to verify if operating command(s) 50 are correct by checking the time delay of the time stamp 30.

The time limit may be set to any arbitrary time limit. The time limit may be set to 500 ms, preferably 300 ms, more preferably 150 ms, most preferably 75 ms. In one example, the time limit is dependent on the speed of which the industrial vehicle 1 is operating and/or presence of humans or other industrial vehicles and their movement patterns.

The industrial vehicle 1 may be any industrial vehicle, such as a forklift, a floor conveyor, an Automated Guided Vehicle, a warehouse crane or a warehouse stacker crane.

Further, the remotely-operated control system comprises the remote control unit 200. The remote control unit 200 comprises a transceiver 216. The remote control unit 200 is connected to the on-board control unit 10 via the communication link 100 between the two transceivers 16, 216. The communication link 100 may be wireless, wired or partly wired and partly wireless. The remote control unit 200 is configured to remotely control motions the industrial vehicle 1 via the on-board control unit 10. As shown in FIG. 2, the remote control unit 200 is configured to receive the sensor data packet 40 and to extract the sensor data 20 and the time stamp 30.

The sensor data 20 may be used for analysing the current situation of the industrial vehicle 1. Further, after analysing the current situation of the industrial vehicle 1, which can be done by the remote control unit 200, by another computer or by an operator, operating command(s) 210 may be received by the remote control unit 200 from the other computer or from the operator.

Yet further, the remote control unit 200 is configured to create the command data packet 70 comprising the time stamp 30 and at least one operating command 50. Each command data packet 70 is a network packet, for example an IP packet, such as an IPv4 packet or an IPv6 packet, or an IPsec packet. Further, the remote control unit 200 is configured to send the command data packet 70 to the on-board control unit 10 via the communication link 100.

In one example, the remote control unit 200 is configured to add an error detection checksum 60 to the command data packet 70. The checksum 60 may be a cyclic redundancy check, CRC, checksum, preferably a CRC-32 checksum. However, any error detection scheme may be used. Thus, it is possible to verify if operating command(s) 50 are correct by checking the checksum 60. Further, the on-board control unit 10 is configured to, after receipt of command data packet(s) 70 from the remote control unit 200, perform an error detection test by determining if the checksum 60 is correct. If both the time delay test and the error detection test are passed, the on-board control unit 10 is configured to control the industrial vehicle 1 based on the received operating command(s) 50.

In a further example, the on-board control unit 10 is configured to send a status message 80 to the remote control unit 200, via the communication link 100, to confirm if the on-board control unit 10 passed the at least one test to control the industrial vehicle 1, or not. The status message 80 comprises information regarding the result of the time delay test and, if applicable, also the result of the error detection test. Thus, the remote control unit 200 will be informed about if the operating command(s) 50 are fulfilled or not. In one alternative the status message 80 is sent to the remote control unit 200 via another communication link.

The communication link 100 may be constituted by any combination of Wi-Fi, wired connection, wireless communication, such as 3G, 4G, 5G, LPWAN, LoRa or any other network connection. The communication link 100 may be regarded as a black channel according to IEC61784-3. Using the Black Channel Principle, safety-relevant data as well as diagnostic information may be exchanged via existing network connections. This enables faster responses. The Black Channel Principle allows transmission of failsafe and standard data via the same network. Independent of the regular data transport mechanism used on that line, safety components can transmit data using an isolated safe protocol tunnelling the underlying network channel. As safe fieldbuses are pure application protocols without physical characteristics of their own, available bandwidth and cycle times depend on the data transport protocol used. Possible transmission errors are known and listed in the relevant standards IEC 61784-3 and IEC 61508.

ISO 13849-1 is based on a probabilistic approach to assessing safety-related control systems. A Performance Level is determined, based on the categories. This is described by the following parameters: - Category (structural requirement) - Mean time to dangerous failure (MTTFd) - Diagnostic coverage (DC) and - Common cause failure (CCF) The objective of functional safety is freedom from unacceptable risk of physical injury or of damage to the health of people either directly or indirectly. Functional safety is achieved when every specified safety function is carried out and the Performance Level, PL, required of each safety function is met. This is achieved by a process that includes the following steps as a minimum: 1) Identifying what the required safety functions are. This means the hazards and safety functions have to be known. 2) Assessment of the risk-reduction required by the safety function. PL applies to an endto-end safety function of the safety-related system, not just to a component or part of the system. According to ISO 13849-1 PL is assessed as follows: The greater the risk, the higher are the requirements of the control system. The contribution of reliability and structure can vary depending on the technology used. As shown in FIG. 3, the level of each hazardous situation is classified in five stages from PLato PLe. PLameans that the contribution of the control function to risk reduction is low, while PLemeans that the contribution of the control function to risk reduction is high.

Severity of injury (S) - Most important S1 = Slight (normally reversible) injury PLa, PLbor PLc S2 = Serious (normally irreversible) injury, including death PLc, PLdor PLe Frequency and/or exposure to a hazard (F) F1 = Seldom to less often and/or exposure time is short PLa/PLbor PLc/ PLd F2 = Frequent to continuous and/or exposure time is long PLb/PLcor PLd/ PLe Possibility of avoiding hazard or limiting harm (P) - Least important PI = Possible under specific conditions PLa, PLb, PLcor PLd P2 = Scarcely possible PLb, PLc, PLdor PLe 3) Ensuring that the safety function performs to the design intent, including under conditions of incorrect operator input and failure modes. This will involve having the design and lifecycle managed by qualified and competent engineers carrying out processes to a recognised functional safety standard. ISO 13849-1 provides safety requirements and guidance on the principles for the design and integration of safetyrelated parts of control systems (SRP/CS), including the design of software. 4) Verification that the system meets the assigned PL by determining the mean time between failures and the safe failure fraction, along with appropriate tests.

) Conduct functional safety audits to examine and assess the evidence that the appropriate safety lifecycle management techniques were applied consistently and thoroughly in the relevant lifecycle stages of product.

Functional safety can be determined without considering the system as a whole and the environment with which it interacts. Functional safety is inherently end-to-end in scope. Any claim of functional safety for a component, subsystem or system should be independently certified to one of the recognized functional safety standards. A certified product can then be claimed to be Functionally Safe to a Performance Level, PL, in a specific range of applications.

By adding a time stamp 30 to each sent command data packet 70 and perform the at least one test for every received command data packet 70, as described in this disclosure, the on-board control unit 10, may be certified for PLcor PLdfor remote control of the industrial vehicle 1. Further, by adding the time stamp 30 to each sent command data packet 70 and possibly also a checksum 60, as described in this disclosure, the remote control unit 200 may be certified for PLcor PLdfor remote control of the industrial vehicle 1. Yet further, the remotely-operated control system, as described in this disclosure, may be certified for PLcor PLdfor remote control of the industrial vehicle 1. In one example, if several sensor data packets 40 are received since the last created command data packet 70, the remote control unit 200 is configured to add the last received time stamp 30 to the next command data packet 70.

The industrial vehicle 1 may comprise basic automatic navigation that requires manual remote control for specific tasks. The remote control unit 200 may also take control of the industrial vehicle 1 when it has stopped due to an obstacle or another problem. An operator operating the remote control unit 200 may serve several industrial vehicles 1.

FIG. 4 illustrates a flowchart of a method carried out by the on-board control unit 10. The method relates to remote control of the industrial vehicle 1 by the remote control unit 200. The method comprises the steps of: creating S1 the sensor data packet 40 comprising sensor data 20 received from the industrial vehicle 1 and the time stamp 30; sending S2 the sensor data packet 40 to the remote control unit 200; - receiving S3 the command data packet 70 from the remote control unit 200, comprising the time stamp 30 and at least one operating command 50; determining S4 the time delay between current time and the received time stamp 30; performing S5 the time delay test by determining if the time delay is lower than the - time limit; and if the time delay test is passed: controlling S6 at least one actuator 14 of the industrial vehicle 1, based on the at least one operating command 50.

The method may comprise the additional step of sending S7 the status message 80 to the remote control unit 200 to confirm if the on-board control unit 10 passed the at least one test to control the industrial vehicle 1, or not.

FIG. 5 illustrates an alternative flowchart of a method carried out by the on-board control unit 10. All steps described in FIG. 4 are also part of the method described in FIG. 5. However, the step of receiving S3 the command data packet 70 from the remote control unit 200, comprising the time stamp 30 and at least one operating command 50, is in this version S3' slightly modified, so that the received command data packet 70 further comprises the checksum 60. Further, the method comprises the step of determining 54' if the checksum 60 is correct. If the checksum 60 is correct, the method continues with determining 54 the time delay between current time and the received time stamp 30, as described in the description of FIG. 4.

The industrial vehicle 1 may be a forklift, a floor conveyor, an Automated Guided Vehicle, AGV, a warehouse crane or a warehouse stacker crane. A forklift is exemplified by FIG. 6 that shows an example of an order picker truck, FIG. 7 that shows an example of a reach truck, or FIG. 8 that shows an example of a stacker truck. The present disclosure is not limited to these particular industrial vehicles 1. Other common lift truck types are: hand pallet truck, walkie low lift truck, towing tractor, electric counterbalanced truck, Internal Combustion Engine Powered Counterbalanced Forklift, battery electric forklift, fuel cell forklift, sideloader or a telescopic handler. Further, a load carrier 6 in the form of forks is not essential for the present disclosure. The industrial vehicle 1 may be electric. The industrial vehicle 1 may have a battery as an energy source. The industrial vehicle 1 may be arranged to mainly operate indoors, in for example a warehouse.

An Automated Guided Vehicle or Automatic Guided Vehicle (AGV) may be a portable robot configured to follow markers or wires in the floor, or uses cameras, magnets, or lasers for navigation. AGVs are most often used in industrial applications to move materials around a manufacturing facility or warehouse. The AGV can tow objects behind them in trailers to which they can autonomously attach. The trailers can be used to move raw materials or finished product. There are many different types of AGVs: Towing Vehicles, AGVS Unit Load Vehicles, AGVS Pallet Trucks, AGVS Fork Truck, AGVS Hybrid Vehicles, Light Load AGVS and AGVS Assembly Line Vehicles.

In the following examples the term fork lift will be used. However this term should be interpreted broadly, including any forklift, or Automated Guided Vehicle, AGV, as well. A fork lift may also be called lift truck, fork truck, fork hoist or forklift truck. It is preferred that the fork lift can detect and avoid objects when operated remotely by a remote control unit 200. The sensor 12 may be a centrally positioned laser sensor. Further, the sensor 12 may be able to detect objects by means of a plane that is angled to the horizontal plane. The sensor 12 is configured to transmit sensor data 20 to the on-board control unit 10 of the fork lift. The onboard control unit 10 is operable to control the travel function and other motions of the fork lift. The travel function of the fork lift is controlling motor, brakes, and other devices needed for driving the fork lift.

Each of the fork lifts of FIGS. 6-8 comprises a transceiver 16. The transceiver 16 is configured to send and receive data packets over the air. The transceiver 16 may comprise an antenna device 5. In one example, the transceiver 16 is configured to send and receive data packets to another transceiver which is connected to Internet by wire. Further, each of the fork lifts comprises an on-board control unit 10. Yet further, each of the fork lifts may comprise a load carrier 6. In addition, each of the fork lifts may comprise a control handle 7 or steering controls 7a. In general fork lifts also comprise a main control unit 10'. The main control unit 10' is only configured to handle signals within the fork lift. External signals, including remote control signals are handled solely by the on-board control unit 10. The on-board control unit 10 is responsible for that safety functions and the performance level, PLc, PLdetc., are fulfilled. The control handle 7 or the steering controls 7a are used by the operator for operating the fork lift in material handling situations as known to the person skilled in the art. The on-board control unit 10 may be incorporated with the main control unit 10', not disclosed in the figures. There is also an internal bus and a travel motor etc. that is common to the person skilled in the art for controlling the functions of the fork lift.

Claims

1. A remotely-operated control system, comprising: a remote control unit (200), connected to an on-board control unit (10) of an industrial vehicle unit (1), via a communication link (100), configured to remotely control motions of the industrial vehicle via the on-board control unit, by sending command data to the on-board control unit; the on-board control unit of the industrial vehicle, connected to the remote control unit via the communication link, being configured to receive sensor data (20) from at least one sensor (12) of the industrial vehicle, send the received sensor data to the remote control unit, receive command data from the remote control unit, and to control the industrial vehicle based on the received command data; characterized in that the on-board control unit is further configured to create a sensor data packet (40) comprising the sensor data received from the at least one sensor and a time stamp (30), and to send the sensor data packet to the remote control unit; wherein the remote control unit is further configured to receive the sensor data packet, and send a command data packet (70) comprising the time stamp and at least one operating command (50); wherein the on-board control unit is further configured to receive the command data packet, comprising the time stamp and the at least one operating command, determine a time delay between current time and the received time stamp, and, perform a time delay test by determining if the time delay is lower than a time limit, and, if the time delay test is passed, control at least one actuator (14) of the industrial vehicle, based on the received at least one operating command.

2. The remotely-operated control system according to claim 1, wherein the remote control unit is further configured to add an error detection checksum (60) to the command data packet, and wherein the on-board control unit is further configured to perform an error detection test by determining if the checksum is correct, and if both the time delay test and the error detection test are passed, control the industrial vehicle based on the received at least one operating command.

3. The remotely-operated control system according to claim 2, wherein the checksum is a cyclic redundancy check, CRC, checksum, preferably a CRC-32 checksum.

4. The remotely-operated control system according to any of claims 1 to 3, wherein the on-board control unit is configured to send a status message (80) to the remote control unit to confirm if the on-board control unit passed the at least one test to control the industrial vehicle, or not.

5. The remotely-operated control system according to any of the preceding claims, wherein the time limit is lower than 500 ms, preferably lower than 300 ms, more preferably lower than 150 ms, most preferably lower than 75 ms.

6. The remotely-operated control system according to any of the preceding claims, wherein the industrial vehicle is a forklift, a floor conveyor, an Automated Guided Vehicle, a warehouse crane or a warehouse stacker crane.

7. An industrial vehicle (1) comprising an on-board control unit (10), connected to a remote control unit (200) via a communication link (100), configured to receive sensor data (20) from at least one sensor (12) of the industrial vehicle, send the received sensor data to a remote control unit, receive command data from a remote control unit, and to control the industrial vehicle based on the received command data packets; characterized in that the on-board control unit is further configured to create a sensor data packet (40) comprising the sensor data received from the at least one sensor and a time stamp (30), and to send the sensor data packet to a remote control unit; wherein the on-board control unit is further configured to receive a command data packet (70) from a remote control unit, comprising the time stamp and at least one operating command (50), determine a time delay between current time and the received time stamp, perform a time delay test by determining if the time delay is lower than a time limit, and, if the time delay test is passed, control at least one actuator (14) of the industrial vehicle, based on the received at least one operating command.

8. The industrial vehicle according to claim 7, wherein the command data packet comprises an error detection checksum (60), and wherein the on-board control unit is further configured to determine if the checksum is correct.

9. The industrial vehicle according to claim 7 or claim 8, wherein the on-board control unit is configured to send a status message (80) to a remote control unit to confirm if the on-board control unit passed the at least one test to control the industrial vehicle, or not.

10. The industrial vehicle according to any of claims 7 to 9, wherein the time limit is lower than 500 ms, preferably lower than 300 ms, more preferably lower than 150 ms, most preferably lower than 75 ms.

11. The industrial vehicle according to any of claims 7 to 10, wherein the industrial vehicle is a forklift, a floor conveyor, an Automated Guided Vehicle, a warehouse crane or a warehouse stacker crane.

12. A method for authentication, by means of an on-board control unit, of remote control of an industrial vehicle by a remote control unit, comprising the steps of: creating (SI) a sensor data packet comprising sensor data received from the industrial vehicle and a time stamp; - sending (52) the sensor data packet to a remote control unit; receiving (S3) a command data packet from a remote control unit, comprising the time stamp and at least one operating command; determining (54) a time delay between current time and the received time stamp; performing (55) a time delay test by determining if the time delay is lower than a time limit; and if the time delay test is passed: controlling (S6) at least one actuator of the industrial vehicle, based on the at least one operating command.

13. The method according to claim 12, wherein the step of the receiving (S3; S3') a command data packet from a remote control unit, comprises that the command data packet further comprises a checksum, and wherein the method further comprises the step of determining (S4') if the checksum is correct.

14. The method according to claim 12 or claim 13, further comprising the step of sending (S7) a status message to a remote control unit to confirm if the on-board control unit passed the at least one test to control the industrial vehicle, or not.

15. The method according to any of claims 12 to 14, wherein the time limit is lower than 500 ms, preferably lower than 300 ms, more preferably lower than 150 ms, most preferably lower than 75 ms.

16. A computer program comprising instructions which, when the program is executed by the on-board control unit, cause the on-board control unit to carry out the method according to any of claims 12 to 15.

17. A computer-readable medium comprising instructions which, when executed by the on-board control unit, cause the on-board control unit to carry out the method according to any of claims 12 to 15.