METHOD FOR DATA TRANSFER BETWEEN A FIRST AND A SECOND MODULE AND ARRANGEMENT WITH MOBILE PARTS FOR EXECUTING THE METHOD

Description

[0001] The invention relates to a method for data transmission between a first and a second module and a system with mobile units for carrying out the method.

[0002] It is well known that for data transmission, a receiver receives the signal from a transmitter.

[0003] From the US 2011 / 0 069 971 A1 The closest state of the art is a method for data transmission using visible light.

[0004] From the DE 601 00 824 T2 is a Proceedings for transmission signal tracking in an optical free-space transmission system.

[0005] From the DE 10 2015 205 220 A1 A tracking system for tracking a wearer of a mobile communication unit is known.

[0006] From the US 2009 / 0 022 496 A1 A method for establishing a communication connection using visible light is known.

[0007] From the US 2009 / 0 316 679 A1 is a wireless broadcast network known.

[0008] From the WO 2009 / 010916 A2 The closest state of the art is known for driving a light source.

[0009] The invention is therefore based on the object of developing a low-interference and / or low-error data transmission.

[0010] According to the invention, the object is achieved by the method according to the features specified in claim 1 and by the system according to the features specified in claim 8.

[0011] Important features of the invention in the method for data transmission between a first and a second module are that the first module has transmitters for light and light-sensitive receivers, wherein the second module comprises transmitters for light and light-sensitive receivers, wherein in a first method step the time base of the first module is synchronized with the time base of the second module, in a second method step the transmitters of the first module each emit a light signal pulse one after the other and / or in numbered order in a respective time range, in particular time slot, wherein the receiver of the second module is determined, in particular by control electronics of the second module, at which the strongest received signal occurs, in particular during the execution of the second method step, wherein the time range, in particular time slot, and / or the number of the time range is determined in which the strongest received signal occurs,in a third method step, the specific time range and / or the specific number is transmitted from the second module to the first module, in a fourth method step, the transmitter of the first module associated with the specific time range and / or the specific number is determined, in particular by control electronics of the first module, and is used for the subsequent data transmission from the first module to the second module, wherein at least one of the modules has a preferred direction, either by differently emitting light cones of the transmitters, or by corresponding reception cones, i.e. light-sensitive areas, of the receiver, in particular wherein at least the second, third and fourth method steps are carried out repeatedly over time.

[0012] The advantage here is that data transmission with as little interference and noise as possible can be achieved. This is because the use of transmitters that emit light, particularly more strongly in one preferred direction than in another, and the use of receivers that also have a preferred direction in their sensitive area, enables directional transmission of signals. Light-emitting jammers are thus suppressed if they are not located in the transmission space used, which contains the connecting line between transmitter and receiver. In addition, the transmitter of the first module and the receiver of the second module that enables signal transmission with the optimal signal-to-noise ratio are repeatedly selected at different times. This selected pair results in the greatest reception amplitude at the receiver, i.e. the best signal-to-noise ratio.The connecting line between the transmitter and receiver of the pair is at least almost parallel to the preferred direction of the transmitter and the preferred direction of the receiver. Since the orientation of the modules relative to each other changes when the handsets move, and thus the deviation of the preferred direction from the direction of the connecting line, the pair is repeatedly redefined over time.

[0013] If the design is advantageous, send In a fifth method step, the transmitters of the second module each emit a light signal pulse one after the other and / or in numbered order in a respective time range, in particular time slot, wherein the receiver of the first module is determined at which the strongest received signal occurs, in particular during the execution of the fifth method step, wherein the time range, in particular time slot, and / or the number of the time range in which the strongest received signal occurs is determined, after which, in a sixth method step, the determined time range and / or the determined number is transmitted from the first module to the second module, after which, in a seventh method step, the transmitter of the second module associated with the determined time range and / or the determined number is determined and used for the subsequent data transmission from the second module to the first module, In particular, at least the fifth, sixth, and seventh method steps are performed repeatedly. The advantage here is that a similarly low-interference transmission can be set up for the return channel, since the pair that enables the best signal-to-noise ratio can also be selected.

[0014] In an advantageous embodiment, the transmitters of the first module have a preferred direction for the light emitted by them and are arranged differently, in particular not in parallel, aligned, In particular, the light cones emitted by the transmitters of the first module are not aligned parallel, the transmitters of the second module have a preferred direction for the light they emit and are arranged differently, in particular not parallel, aligned, in particular, the light cones emitted by the transmitters of the second module are not aligned parallel. The advantage here is that interfering light sources can be suppressed, because the communication channel only requires a limited spatial area.

[0015] In an advantageous embodiment, a message is transmitted after the fourth and / or seventh method step. The advantage here is that, according to the invention, the transmitter and receiver pair with the best signal-to-noise ratio is selected, thus allowing the messages to be transmitted with minimal errors and interference.

[0016] In an advantageous embodiment, the transmitters are designed as LEDs and the receivers as light-sensitive components, in particular phototransistors or photodiodes. This is advantageous because it allows for directed light transmission and reception with a preferred direction.

[0017] In an advantageous embodiment, the second module is located within the transmission range of at least one transmitter of the first module, and the first module is located within the transmission range of at least one transmitter of the second module. This advantageously allows for message transmission.

[0018] In an advantageous embodiment, the light signal pulses emitted by the transmitters in the second method step are all modulated in the same way, so that each of the light signal pulses contains the same message. The advantage here is that the training sequence carried out in the second method step makes it possible to determine the pair with the best signal-to-noise ratio, while at the same time a message can still be transmitted during this time. The disadvantage here is that each of the transmitters of the first module successively emits the same light signal pulse, onto which the same message is modulated. Thus, the data transmission rate during the training sequence is lower than during normal data transmission. The more transmitters the first module has and the shorter the light signal pulses, the lower the data transmission rate.

[0019] However, if the first module, for example, has only four transmitters, and the light signal pulses each take up almost a quarter of the total duration of the training process, i.e., the second process step, a data transmission rate can still be achieved that is slightly less than a quarter of the usual data transmission rate. With N transmitters, a data transmission rate can be achieved that is slightly less than the Nth part of the usual data transmission rate.

[0020] Important features in the system with mobile units for carrying out an above-mentioned method are that each of the mobile units has at least one module, which in each case has transmitters, in particular for light, and in particular light-sensitive receivers, in particular wherein the transmitters and receivers of the respective module are connected to control electronics of the respective mobile unit.

[0021] The advantage here is that the handset can transmit messages to the other handset, allowing mutually influenced operation. On the one hand, this avoids a collision, and on the other hand, an intralogistics transport task can be carried out jointly. Information can also be transmitted. Directed transmission also makes it possible to pass messages from a first handset via a second handset to a third handset, even if there is no communication link between the first and third handset. In this way, messages can also be sent to handsets that are too far away, or to handsets with which there is no direct, i.e. straight-line, line of sight. This enables low-interference communication around an obstacle.

[0022] In an advantageous embodiment, the mobile units can be moved along a travel surface of the system, and the modules are each at the same distance from the travel surface. This is advantageous because the message transmission can be carried out in a defined plane or area that is at a constant distance from the travel surface.

[0023] In an advantageous embodiment, the transmitters of each module are arranged along a flat, curved curve, with the light cones emitted by the transmitters being differently oriented. This is advantageous in that a wide spatial angle can be covered despite the transmitters each radiating narrowly, i.e., within a small solid angle range.

[0024] In an advantageous embodiment, no signal transmission is possible between a first and a third mobile part, in particular because of an intermediate obstacle and / or because of a distance that is too great, wherein data is transmitted between the first and a second mobile part and between the second and the third mobile part, wherein the method according to one of claims 1 to 7 is carried out between the modules of the first and second mobile part and the method according to one of claims 1 to 7 is carried out between the modules of the second and third mobile part. The advantage here is that if the distance is too great or if there is an intermediate obstacle to light, bridging is possible by means of an intermediate second mobile part which has two modules, so that the information received by the first of the two modules from a module of the first mobile part can be transmitted by means of the second of the two modules of the second mobile part to the third mobile part, in particular its module.

[0025] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0026] The invention will now be explained in more detail with the aid of schematic illustrations: In the Figure 1 A first module 1 and a preferably identically constructed second module 4 are shown schematically.

[0027] In the Figure 2 The transmitted and received signal curves are shown schematically.

[0028] As shown in the figures, the first module 1 comprises four transmitters, in particular LEDs, whose emittable light cones are directed in different directions.

[0029] Each transmitter is assigned a respective receiver, in particular a photodiode or phototransistor, whose sensitive area is shaped similarly to the corresponding light cone, thus also having a preferred direction. In the simplest case, the preferred direction of the light cone of the respective transmitter is parallel to the preferred direction of the respective receiver.

[0030] Preferably, the transmitters are arranged along a flat curve, in particular a circular path, and are regularly spaced from one another along this curve.

[0031] The second module 4 is preferably identical to the first module 1.

[0032] The first module 1 is arranged on a first handset and the second module 4 is arranged on a second handset, which moves independently, in particular automatically guided, relative to the first handset in a system.

[0033] To establish communication, the best transmission channel is determined periodically by having the transmitters of the first module 1 send light pulses, and then determining the receiver that detects the highest received amplitude. A transmission channel is then established between this receiver and the transmitter with the strongest signal for that receiver. This determination and establishment process is repeated periodically.

[0034] This is now described in more detail below: In a time-deterministic grid, signals are sent from the first module 1 and received by the second module 4 or vice versa.

[0035] For this purpose, a training signal curve is attached to each message, identified by the time range t_TX_DATA.

[0036] The training signal consists of four consecutive time periods, specifically time slots, with a different LED of the first module 1 emitting a light signal pulse in each of the time slots. The energy and duration of each of the light signal pulses are the same.

[0037] According to Figure 1 sends a first transmitter of the first module 1 transmits a light signal pulse in a first time slot t_int1, a second transmitter of the first module 1 transmits a light signal pulse in a second time slot t_int2, a third transmitter of the first module 1 transmits a light signal pulse in a third time slot t_int3 and a fourth transmitter of the first module 1 transmits a light signal pulse in a fourth time slot t_int4.

[0038] The signal E received by one of the receivers of the second module 4 is in Figure 2and shows a maximum at the third light signal pulse. This would make it possible to establish a communication channel between the third transmitter and the receiver. However, the Figure 2 The received signals (not shown) from the other receivers of the second module 4 are evaluated. The communication channel is then established between the third transmitter and the receiver that received the strongest signal. If necessary, a different transmitter is used instead of the third transmitter if it has produced a stronger signal at one of the receivers.

[0039] In other words, the transmitter-receiver pair that can generate the strongest received signal is determined.

[0040] As in Figure 2As shown, the first message packet sent from the first module 1 to the second module 4 is followed by a first training signal with the four light signal pulses from the transmitters of the first module 1.

[0041] The receiver whose received signal had the highest amplitude is determined. The transmitter corresponding to this highest amplitude is determined, Figure 2 i.e. the third sender, and this information about the identity of the corresponding sender, i.e. the third sender, is transmitted to the first module 1 in the next message packet, which is sent from the second to the first module 1.

[0042] In this way, the appropriate communication channel is established for transmitting messages from the first to the second module. In the example, the third transmitter of the first module 1 and the specific receiver of the second module 4 are used for message transmission from the first to the second module.

[0043] The pair to be used for the rear channel is then determined: For this purpose, the second module 4 also sends a training signal, which in turn consists of light signal pulses to be sent individually by the transmitters.

[0044] In this way, it is now possible to determine the receiver of the first module 1 that received the strongest amplitude. At the same time, it is possible to determine the transmitter of the second module 4 that transmitted this strongest signal.

[0045] This also determines the best transmitter-receiver pair for the return channel.

[0046] In the example, this is the second transmitter of the second module 4 and the receiver of the first module 1 that detects the strongest received signal.

[0047] The pairs thus determined are used for the subsequent transmission of the messages until the currently best sensor-receiver pairs are determined again using training signals.

[0048] When transmitting messages, only the specified transmitters and receivers are used. The other transmitters and receivers are not used. This prevents interference with or from other handsets. Only the light cone 3 generated by the transmitter, which is directed at the receiver of the other module (1, 4), is used for message transmission. This minimizes the irradiation of other spatial areas, where, for example, other modules of other handsets are moved.

[0049] In further embodiments according to the invention, the light signal pulses themselves are also modulated, so that each of the light signal pulses in the training signal pattern transmits the same message, but in particular in different preferred directions. The receivers thus receive this message with less or more noise depending on the received amplitude. However, after determining the strongest received signal, the message transmitted with this signal can also be detected with low error.

[0050] In further embodiments according to the invention, each transmitted message is followed by a training signal so that an optimal update takes place when determining the currently best transmitter-receiver pairs. List of reference symbols

[0051] 1 first module 2 light transceiver, in particular LED with photodiode or phototransistor 3 light cone 4 second module E reception t_TX_DATA message transmission t_int1 first time slot t_int2 second time slot t_int3 third time slot t_int4 fourth time slot

Claims

1. Method for transmitting data between a first and a second module (1, 4), wherein the first module (1) comprises transmitters for light and also light-sensitive receivers, wherein the second module (4) comprises transmitters for light and also light-sensitive receivers, characterised in that - in a first method step, the time base of the first module (1) is synchronised with the time base of the second module (4), - in a second method step, the transmitters of the first module (1) each emit a light signal pulse individually one after the other and / or in numerical order within a particular time range, in particular a time slot, - wherein the particular receiver of the second module (4) at which the strongest receive signal occurs, in particular during the execution of the second method step, is determined, in particular by control electronics of the second module (4), wherein the particular time range, in particular the time slot, and / or the number of the particular time range in which the strongest receive signal occurs is / are determined, - in a third method step, the determined time range and / or the determined number is / are communicated from the second module (4) to the first module (1), - in a fourth method step, the particular transmitter of the first module (1) that is associated with the determined time range and / or the determined number is determined, in particular by control electronics of the first module (1), and is used for the subsequent transmission of data from the first module (1) to the second module (4), wherein at least one of the modules has a preferential direction, either as a result of differently radiating light cones of the transmitters or as a result of corresponding receive cones, i.e. light-sensitive regions, of the receivers, in particular wherein at least the second, third and fourth method steps are carried out recurrently over time.

2. Method according to claim 1, characterised in that - in a fifth method step, the transmitters of the second module (4) each emit a light signal pulse individually one after the other and / or in numerical order within a particular time range, in particular a time slot, - wherein the particular receiver of the first module (1) at which the strongest receive signal occurs, in particular during the execution of the fifth method step, is determined, wherein the particular time range, in particular the time slot, and / or the number of the particular time range in which the strongest receive signal occurs is / are determined, - in a sixth method step, the determined time range and / or the determined number is communicated from the first module (1) to the second module (4), - in a seventh method step, the particular transmitter of the second module (4) that is associated with the determined time range and / or the determined number is determined and is used for the subsequent transmission of data from the second module (4) to the first module (1), in particular wherein at least the fifth, sixth and seventh method steps are carried out recurrently over time.

3. Method according to claim 1 or claim 2, characterised in that the transmitters of the first module (1) have a preferential direction for the light emitted by them and are arranged in a differently oriented manner, i.e. in particular not in parallel, in particular wherein the light cones radiated by each transmitter of the first module (1) are not oriented in parallel, the transmitters of the second module (4) have a preferential direction for the light emitted by them and are arranged in a differently oriented manner, i.e. in particular not in parallel, in particular wherein the light cones emitted by each transmitter of the second module (4) are not oriented in parallel.

4. Method according to any of the preceding claims, characterised in that a message is transmitted after the fourth and / or after the seventh method step.

5. Method according to any of the preceding claims, characterised in that the transmitters are configured as LEDs, and the receivers are configured as light-sensitive elements, in particular phototransistors or photodiodes.

6. Method according to any of the preceding claims, characterised in that the second module (4) is located within the transmission range of at least one transmitter of the first module (1), and in that the first module (1) is located within the transmission range of at least one transmitter of the second module (4).

7. Method according to any of the preceding claims, characterised in that the light signal pulses emitted by the transmitters in the second method step are all modulated in the same way such that each of the light signal pulses contains the same message.

8. Facility comprising mobile components configured for carrying out a method according to any of the preceding claims, characterised in that each of the mobile components has at least one module (1), each of which comprises transmitters for light and also light-sensitive receivers, wherein the transmitters and receivers of each module (1) are connected to control electronics of the particular mobile component.

9. Facility according to claim 8, characterised in that the mobile components can travel on a travel surface of the facility, and the modules are each at the same distance from the travel surface.

10. Facility according to claim 8 or claim 9, characterised in that the transmitters of each module (1) are arranged along a smooth arcuate curve, wherein the light cones emitted by the transmitters are oriented differently.

11. Facility according to claim 8, claim 9 or claim 10, characterised in that signals cannot be transmitted between a first and a third mobile component, in particular because of an obstacle arranged therebetween and / or because they are at too great a distance from one another, wherein data are transmitted between the first and a second mobile component and between the second and the third mobile component, wherein the method according to any of claims 1 to 7 is carried out between the modules of the first and the second mobile component, and the method according to any of claims 1 to 7 is carried out between the second and the third mobile component.