This application is based upon and claims priority to, under relevant sections of 35 U.S.C. § 119, German Patent Application No. 10 2017 102 117.5, filed Feb. 3, 2017, the entire contents of which are hereby incorporated by reference.
The present invention relates a system and associated method for determining the position of at least one industrial truck in an area having a plurality of stationary radio stations.
Various approaches are known for determining the position of industrial trucks in warehouse areas and other defined environments. It is known to place an RFID transponder in the floor. When an industrial truck drives over the RFID transponder, its position can be communicated. In the field of radio engineering, for example, propagation time measurements and/or angle of incidence measurements to determine the position of the industrial truck relative to immovably installed units are known.
A method and system are known from DE 10 2009 004 854 B4 to determine the position of an industrial truck in which a multi-axis gyro sensor, in particular a gyroscope, is used.
A method for approaching a storage bin with an industrial truck is known from DE 10 2001 018 520 A1, in which the current position of the industrial truck is detected, and a preselected lift height value matching the height of the bin to be approached is set for the current position.
A device for determining the position of an industrial truck is known from DE 10 2009 013 671 A1. In this context, a plurality of light sources are positioned at predefined locations, and a beam clearly identifying the light source is emitted by the light sources. An industrial truck evaluates the incoming beam with the inclusion of the relative angles to each other in order to determine its current position and orientation between three light sources.
The object of the invention is to provide a system and associated method for determining the position of at least one industrial truck in an area having a plurality of stationary radio stations that can determine the current position of the industrial truck with maximum precision.
In an embodiment, a method is provided for determining a position of at least one industrial truck in an area having a plurality of stationary radio stations. The term “position” in this context comprises the spatial position of the industrial truck, and its orientation in this position. The position of the at least one industrial truck is determined in an area having a plurality of stationary radio stations that transmit a position signal in response to a position-determining signal. The industrial truck is equipped with a mobile radio station. Stationary and mobile radio stations are configured as transmitting and receiving units that are capable of receiving and transmitting radio signals. In an embodiment, vehicle data on the vehicle speed and/or a steering angle in the vehicle are determined. The determined vehicle data describe the actual state or the target state of the vehicle. In an embodiment, a position-determining signal is transmitted by the mobile radio station to the plurality of stationary radio stations. The plurality of stationary radio stations each transmit their positions signal in response to a received position-determining signal. Additional data may be appended to the position-determining signal and/or the position signal. Vehicle data are appended as the additional data to the position-determining signal(i.e., to the signal emitted by the industrial truck) that refer to a vehicle speed and/or a steering angle of the industrial truck. In the position signal as the signal emitted by the stationary radio stations, the additional data comprise position data of industrial trucks. In an embodiment, the mobile radio station receives a plurality of position signals that originate from at least three different stationary radio stations. By using three stationary radio stations, the position of the industrial truck is clearly determined.
In an embodiment, the current position is determined by a Kalman filter with the inclusion of the determined vehicle data. The Kalman filter can work with an expanded state space for the industrial truck that, for example, also comprises its translatory or rotary movement, and thus enables more precise positioning.
The vehicle data may include the current position of the industrial truck. In this manner, the current vehicle positions are also provided by the position-determining signals for the stationary radio stations so that the stationary radio stations can distribute the positions of the industrial trucks to all mobile radio stations by their position signals in the appended additional data.
In an embodiment of the method, the mobile radio station receives information on the current position of other industrial trucks. This information is determined from the received position signals. The position data on participating industrial trucks is exchanged at the same time on the radio channel for determining position. In one possible embodiment, this information is exchanged between the mobile radio stations (i.e., between the respective vehicles).
In an embodiment, information on the current positions of the industrial trucks is transmitted to all industrial trucks proceeding from the stationary radio stations. The stationary radio stations determine the data on the current positions of the industrial trucks from the received position-determining signals to which the current vehicle position is also appended.
In an embodiment of the method, the at least one industrial truck throttles its own speed and/or changes its steering angle when the evaluation of the positions and/or movements of other vehicles indicate a collision hazard. In this embodiment, the industrial truck independently detects from the available data that there is an elevated risk of a collision at its position or in its environment. Consequently, the vehicle speed is then throttled and/or the driving direction is changed. When the vehicle speed is throttled, it is easier for the user of the industrial truck to react to pending collisions and avoid crashes. In the event of a pending collision, a change in the driving direction can also help generate time for an evasive maneuver.
In another embodiment, a plurality of the mobile radio stations answer with a vehicle position signal in response to a position-determining signal so that an industrial truck receiving the vehicle position signal can determine its distance. This distance determining method using transmitted position signals can also be used in addition to the exchange of information on the current position of the other industrial trucks.
A system determines the position of at least one industrial truck in an area having a plurality of stationary radio stations that are configured to transmit a position signal in response to a position-determining signal. Each industrial truck has a mobile radio station that is configured to transmit a position-determining signal and receive position signals. Moreover, an evaluation unit is configured to append additional vehicle data to a position-determining signal to be transmitted and to separate position data on the industrial trucks from received position signals. The evaluation unit is also configured to determine a current vehicle position from at least three position signals. The system comprises an evaluation unit that, on the one hand, determines the current vehicle position from received position signals and, on the other hand, is designed to transmit vehicle data with position-determining signals, and/or to separate position data from received position signals.
In an embodiment, the vehicle data comprise the vehicle speed and/or a steering angle of the industrial truck. In an embodiment, the vehicle data also comprise a current vehicle position. In a further embodiment, the system creates a way to distribute position data to the individual industrial trucks particularly effectively between all the vehicles. On the one hand, the vehicles report their current vehicle position with the vehicle data to the stationary radio stations, whereas at the same time, the stationary radio stations distribute the position data of the industrial trucks by the position signals to the industrial trucks. In this manner, each industrial truck is provided with the position data of the other industrial trucks so that an avoidance of a collision can be carried out in a known manner.
In another embodiment, the evaluation unit is configured to determine position data of other industrial trucks from the received position signals. In this manner, position data on the other industrial trucks is locally available to the individual industrial trucks.
In another embodiment, the mobile radio stations are configured to receive signals on the respective position of another industrial truck from the other mobile radio stations.
The position data on the plurality of industrial trucks is distributed to the other industrial trucks in this preferred embodiment directly between the mobile radio stations, and not just by the stationary radio stations.
In another embodiment, the stationary radio stations are configured to determine current positions of industrial trucks from the received position-determining signals. The current positions of the industrial trucks determined in this manner are then forwarded to the other industrial trucks in the position signals.
Preferred embodiments of the invention are explained in greater detail below. In the following:
Still referring to
The stationary radio stations 30, 32, 34 are also termed anchors. As shown in
As shown in
Still referring to
Moreover, the vehicle speed and the steering angle position of the industrial truck are transmitted to the mobile radio station. The transmission is carried out either by the vehicle's own CAN bus 28 (
In the industrial truck, the determination of the position by radio is supplemented with the current data on the vehicle speed and steering angle by using the Kalman filter and processed into precise position information. In this context, not only the position of the individual vehicle is determined, but the position of the other vehicles can be determined as well. The other industrial trucks can also use a Kalman filter when the vehicle speed and/or the steering angle of the respective industrial truck are available.
The system for precise determination of position also has the advantage that signals can be generated for the behavior of the industrial truck in a position-dependent manner. For example, the vehicle speed can be reduced in areas in which many other industrial trucks are located and are moving. The position of the industrial truck can also be exchanged between each other or via the stationary radio stations 30, 32, 34, where movements are recognized, and the vehicle speed can be reduced if the density of vehicles is excessive.
It is also possible to perform a determination of the distance relative to other vehicles by measuring propagation time in this instance as with the stationary radio stations.
Number | Date | Country | Kind |
---|---|---|---|
10 2017 102 117.5 | Feb 2017 | DE | national |