SYSTEM WITH MOBILE PART MOVABLE ON A TRAVEL SURFACE OF THE SYSTEM

Description

[0001] The invention relates to a system with a mobile part that can be moved on a travel surface of the system.

[0002] It is generally known that a mobile unit can be moved along a track. Mobile units that can be moved along a rail are called rail vehicles.

[0003] From DE 10 2005 046 456 A1, the closest prior art discloses a method for determining the location of moving objects.

[0004] A localization system for a rail vehicle is known from US 2017 / 0 057 528 A1.

[0005] DE 10 2017 212 955 A1 describes a method for determining the speed of a rail vehicle using an on-board camera.

[0006] A method for determining position is known from EP 1 418 109 A1.

[0007] A method for pulse width error detection is known from EP 1 473 210 A1.

[0008] From theDE 10 2005 046 456 A1 The closest prior art is a method for determining the location of moving objects.

[0009] From the DE 10 2010 045 720 A1 Monitoring of measuring arrangements with measuring sensors for determining speed values in rail vehicles is known.

[0010] From the DE 10 2016 223 435 A1 Distance and speed measurement using image recordings is known.

[0011] The invention is therefore based on the object of developing a system in which safety is to be improved.

[0012] According to the invention, the object is achieved in the system according to the features specified in claim 1.

[0013] The advantage here is that the speed is recorded using two differently operating sensors, thus increasing safety. A cross-comparison of the determined speed values is also performed. This allows the speed to be determined with increased safety. If an unacceptably large deviation between the determined values is detected, a command is generated to initiate a safe state, in particular a shutdown signal and / or STO signal.

[0014] In an advantageous embodiment, the travel surface is a two-dimensional surface, in particular the floor of the system. This is advantageous because the mobile unit can be designed as an intralogistics vehicle, allowing the speed to be recorded two-dimensionally, since the speed vector of the mobile unit is aligned parallel to the travel plane.

[0015] In an advantageous embodiment, the travel surface is a rail, and the mobile part is a rail vehicle that can be moved along the rail. This is advantageous because the invention can also be applied to rail vehicles, thus allowing a reliable determination of the associated one-dimensional velocity vector with high accuracy.

[0016] According to the invention, the first sensor is a radar sensor and the second sensor is a light sensor, with the light beams transmitted and received by the light sensor penetrating a transparent area of the housing. The advantage here is that the radar sensor operates differently than the light sensor. In particular, the radar beam penetrates the plastic housing. The light sensor emits light, which is reflected by the travel surface, and detects the reflected light to determine the speed.

[0017] In an advantageous embodiment, a third sensor is arranged within the housing. This third sensor operates according to a third physical principle that is different from the first and second principles. This is advantageous in that further increased safety is achieved through further comparison and monitoring for exceeding a permissible deviation from the speed determined using the sensor signals from the other two sensors. The third sensor is preferably designed as an acceleration sensor, whose detected acceleration values are integrated over time to determine the speed.

[0018] In an advantageous embodiment, the second computer unit determines a third value of the mobile device's speed from the sensor signal of the first sensor, in particular, and monitors for exceeding a permissible degree of deviation from the first and / or second value. The advantage here is that security is increased by this monitoring, and thus corresponding release information can be transmitted as verification information via a secure communication interface.

[0019] In an advantageous embodiment, the first computer unit determines a fourth value for the speed of the mobile device from the sensor signal of the second sensor, which value differs from the second value, and monitors this fourth value for exceeding a permissible degree of deviation from one of the other values. The advantage here is that security is increased by this monitoring and thus corresponding release information can be transmitted as verification information via a secure communication interface. This is because by using a different sampling rate for the sensor signal of the second sensor and / or by using different filtering, the fourth value differs from the second value. As long as the difference is small enough, no error exists. However, if a critical degree of deviation is exceeded, an error exists.For example, the fourth value is determined at a low sampling rate, and the second value exceeds the fourth value by a critical degree of deviation. This is the case, for example, if the second sensor is subjected to a sudden, unacceptable impact, particularly an unacceptably high jolt.

[0020] In an advantageous embodiment, the second computer unit determines a fourth value of the handset's speed from the sensor signal of the second sensor and monitors for exceeding a permissible degree of deviation from one of the other values. The advantage here is that this monitoring increases security, allowing corresponding release information to be transmitted as verification information via a secure communication interface.

[0021] In an advantageous embodiment, the first computer unit is designed to be diverse from the second computer unit. This has the advantage of increasing security and reducing the likelihood of systematic errors.

[0022] In an advantageous embodiment, the first computer unit is designed differently from the second computer unit. This has the advantage of increasing security and reducing the likelihood of systematic errors.

[0023] In an advantageous embodiment, the sensor arrangement has a safety-related electrical output, In particular, a shutdown signal or a command for activating a safe state can be provided via the output, in particular via one or more contacts of a connector part arranged in or on the housing. The advantage here is that safety is increased by providing a safe enable signal and shutdown signal.

[0024] In an advantageous embodiment, the sensor arrangement has a safety-related electrical communication interface, in particular which is available via one or more contacts of a connector part arranged in or on the housing. The advantage here is that the speed values of a control unit can be made available to a controller of the handset, so that the detected speed, i.e. the actual speed value, of the drive of the handset is regulated to a target speed value. Non-safe speed values can also be used for this control, for example all the speed values determined from the sensor signal of the first sensor, in particular the radar sensor. The verification information additionally transmitted on the communication interface can be used by a safety controller of the handset for control, so that a shutdown or another safe state, such as the safe maintenance of a constant speed, can be initiated.The safety controller is responsible only for safety-relevant tasks. The other handset controller is responsible for other tasks, with safety-relevant actions being monitored directly and / or indirectly by the safety controller.

[0025] In an advantageous embodiment, values and associated verification information can be transmitted via the communication interface from the sensor arrangement to a controller of the handset, in particular to a regulator, in particular a speed regulator of the handset controller, in particular wherein, in addition to the speed values, the verification information is transmitted bidirectionally via the communication interface. It is advantageous in this case that the safety-relevant information is used by a safety-related controller, in particular a safety controller. However, the speed values can be used by the controller even if the verification information is negative, i.e., an unsafe state has been reached. A safety-related shutdown signal acts on the drive of the handset, so that the controller's manipulated variable can become ineffective in the event of a safety event.

[0026] According to the invention, the transparent area of the housing is a partial area of the housing, and the radar sensor is located further away from the transparent partial area than from the rest of the housing, which is particularly opaque to light. Advantageously, the light sensor can be placed directly behind the transparent area, and the radar sensor is located further away from the transparent area than the light sensor.

[0027] Further advantages arise from the subclaims.

[0028] The invention will now be explained in more detail using schematic illustrations: In the Figure 1 is a schematic diagram of a mobile part according to the invention which can be moved on a travel surface 1, in particular a travel plane or rail, and which has a sensor arrangement. Figure 2 the sensor arrangement with its housing 20 is schematically sketched.

[0029] As shown in the figures, a mobile unit is movable on a travel surface 1. If the travel surface 1 is two-dimensional, the mobile unit is movable on a plane in at least two non-parallel spatial directions. For example, the mobile unit then functions as an automated guided vehicle (AGV), an intralogistics assistant (MLA), or an automated guided vehicle (AGV).

[0030] If the travel surface 1 is only one-dimensional, i.e. designed as a rail, the mobile unit functions as a rail vehicle.

[0031] The sensor arrangement is preferably arranged on the underside of the handset and has a housing 20 which is fastened, in particular screwed, to the chassis of the handset.

[0032] The housing 20 is preferably made of plastic.

[0033] The sensor arrangement comprises a radar sensor 2, whose transmitted radar beams 6 and received radar beams 7 thus penetrate through the housing 20.

[0034] The housing 20 has, at least in part or as a whole, a surface that is transparent to light, so that the light transmitted and received by the light sensor 3 penetrate through this transparent surface.

[0035] The sensor arrangement also includes a three-dimensional acceleration sensor 5. This is preferably formed by three strain gauges arranged perpendicular to each other, so that the deflection of a mass in the respective directions can be detected, and the spatial acceleration detector can be inferred from this.

[0036] From the sensor signals, the speed of the mobile part relative to the travel surface 1 is determined by an evaluation electronics 4, which is also arranged within the housing 20 of the sensor arrangement.

[0037] A connector part is arranged on the housing 20 so that a secure two-channel electrical output 21 can be provided to the mobile part on the one hand and a secure communication interface 22 on the other hand.

[0038] The evaluation electronics 4 comprises a first computer unit, in particular a microprocessor, and a second computer unit, in particular a microprocessor, which compare the speed determined from the sensor signal of the radar sensor 2 with the speed determined from the sensor signal of the light sensor 3. If a permissible deviation is exceeded, an STO signal is generated, i.e., a command signal for initiating a safe state, in particular, a shutdown signal.

[0039] The two computing units are not identical, but different. The comparison is performed crosswise. This means that each of the two computing units compares the two speed signals and monitors for any deviations exceeding the permissible limit.

[0040] The STO signal is sent via the safe output 21 as a binary signal to the handset control and also to a safety control that is additionally located on the handset and can also generate a shutdown signal.

[0041] In addition, the determined speed values are forwarded via the secure communication interface 22. In addition to the determined speed values, safety-related information is also exchanged, i.e., transmitted bidirectionally. This safety-related information can also be referred to as verification information. A check information is transmitted for each transmitted data packet and, in turn, confirmed by the receiver if it was transmitted correctly.

[0042] In any case, the speed values provided at the communication interface 22 are fed to a control unit controlling the handset. Thus, the speed can be controlled to a target value using the recorded speed values, which may not have been confirmed as reliable, as actual values.

[0043] In further embodiments according to the invention, instead of the radar sensor 2, a sensor with a first physical operating principle is used to detect the speed values, and instead of the light sensor 3, a sensor with a second physical operating principle is used, wherein the first operating principle is different from the second operating principle.

[0044] In further embodiments of the invention, position data, in particular angle values, are determined and transmitted instead of speed values. For speed control, the time-differentiated signal is used as the actual speed value. List of reference symbols

[0045] 1 Travel surface, especially rail 2 Radar sensor 3 Light sensor 4 Evaluation electronics 5 Acceleration sensor 6 Emitted radar beam 7 Received radar beam 8 Emitted light 9 Received light 20 Housing 21 Safe two-channel electrical output 22 Safe communication interface

Claims

1. Facility comprising a movable part which is movable on a movement surface of the facility, wherein a sensor assembly is fastened to the movable part, in particular to the underside of the movable part, wherein the sensor assembly comprises a housing, in particular a plastic housing, wherein a first sensor, which operates in accordance with a first physical operating principle, and a second sensor, which operates in accordance with a second physical operating principle, are arranged within the housing, wherein the first operating principle is different than the second operating principle, wherein the sensor signal of the first sensor, in particular the sensor signals of both sensors, can be fed to a first computing unit of an evaluation electronics arranged within the housing, wherein the sensor signal of the second sensor, in particular the sensor signals of both sensors, can be fed to a second computing unit of the evaluation electronics, wherein the first computing unit is designed to determine a first value of the speed of the movable part from the sensor signal of the first sensor, wherein the second computing unit is designed to determine a second value of the speed of the movable part from the sensor signal of the second sensor and to monitor it for exceeding a permissible extent of deviation from the first value, wherein the first sensor is a radar sensor and the second sensor is a light sensor, wherein the housing is configured in such a way that the light beams emitted and received by the light sensor can penetrate a transparent region of the housing, and wherein the transparent region of the housing is a portion of the housing and the radar sensor is further away from the transparent portion than from the rest of the housing, which in particular is opaque to light.

2. Facility according to claim 1, wherein the movement surface is a two-dimensional surface, in particular the floor of the facility, or in that the movement surface is a rail and the movable part is a rail vehicle which is movable on the rail.

3. Facility according to any one of the preceding claims, wherein a third sensor is arranged within the housing, which third sensor operates in accordance with a third physical operating principle, which is different than the first and the second operating principle, in particular wherein the third sensor is an acceleration sensor, in particular a three-dimensional acceleration sensor, in particular wherein the acceleration sensor comprises, for each of the dimensions, at least one strain gauge which makes it possible to detect the deflection of a mass.

4. Facility according to any one of the preceding claims, wherein the second computing unit is designed to determine a third value of the speed of the movable part from the sensor signal of the first sensor and to monitor it for exceeding a permissible extent of deviation from the first and / or second value.

5. Facility according to any one of the preceding claims, wherein the first computing unit is designed to determine a fourth value of the speed of the movable part from the sensor signal of the second sensor and to monitor it for exceeding a permissible extent of deviation from one of the other values.

6. Facility according to any one of the preceding claims, wherein the second computing unit is designed to determine a fourth value of the speed of the movable part, which is different than the second value of the speed, from the sensor signal of the second sensor and to monitor it for exceeding a permissible extent of deviation from one of the other values, and to use, when determining the fourth value, a different sampling rate of the sensor signal and / or a different filtering than when determining the second value.

7. Facility according to any one of the preceding claims, wherein the first computing unit is embodied diversely in relation to the second computing unit, i.e. in particular different implementations are used for redundant individual components of the first and the second computing unit, in particular in order to reduce the risk of a simultaneous failure of the two redundant components.

8. Facility according to any one of the preceding claims, wherein the first computing unit is embodied differently than the second computing unit.

9. Facility according to any one of the preceding claims, wherein the sensor assembly comprises a safety-oriented electrical output, in particular wherein a switch-off signal or a command to activate a safe state can be provided via the output, in particular which is available via one or more contacts of a plug-in connector part arranged in or on the housing.

10. Facility according to any one of the preceding claims, wherein the sensor assembly comprises a safety-oriented electrical communication interface, in particular which is available via one or more contacts of a plug-in connector part arranged in or on the housing.

11. Facility according to any one of the preceding claims, wherein values from the sensor assembly can be transmitted via the communication interface to a controller of the movable part, in particular to a regulator, in particular a speed regulator of the controller of the movable part, as well as associated verification information, in particular wherein, in addition to the speed values, the verification information can be transmitted bidirectionally via the communication interface.