Entering the sensing system
By introducing a first and second silent sensor unit into the entry sensing system, the problem of limited cross-angle sensing range of photoelectric sensors is solved, enabling rapid invalidation and accurate detection of permitted objects in confined spaces.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DAIFUKU CO LTD
- Filing Date
- 2021-04-23
- Publication Date
- 2026-05-26
Smart Images
Figure CN115702308B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an entry sensing system for sensing objects entering a predefined area. Background Technology
[0002] Japanese Patent Application Publication No. 2010-133503 discloses a safety system in which a light curtain (30) is provided at the loading entrance for moving items (31) into a specific area to sense workers entering the specific area from the loading entrance (in the background art, the symbols in parentheses are symbols of the referenced documents). The light curtain (30) also senses the items (31) to be moved in, and therefore has a function to disable the sensing of the light curtain (30) when the items (31) are moved in (a silence function). Specifically, two sets of retroreflective photoelectric sensors are provided as silence sensors (the silence sensors have intersecting sensing ranges near the sensing surface of the light curtain (30) in plan view), and when the items (31) to be moved in are sensed near the loading entrance along the loading path, the sensing by the light curtain (30) is disabled.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent document 1: Japanese Patent Application Publication No. 2010-133503. Summary of the Invention
[0006] The problem that the invention aims to solve
[0007] In the above scenario, since the sensing ranges of the two sets of retroreflective photoelectric sensors overlap, it is impossible to adequately ensure the distance from the detection surface of the light curtain to the detection position of the object without increasing their intersection angle. However, to increase this intersection angle, a wider installation space is required to position the two sets of retroreflective photoelectric sensors away from the light curtain. Furthermore, when the installation space is limited, it is sometimes impossible to ensure the distance between the sensing position of the silent sensor and the sensing position of the light curtain, and the light curtain cannot be properly deactivated depending on the shape of the object.
[0008] In view of the above background, it is desirable to provide a technique that can appropriately disable the sensing of objects allowed to enter in an entry sensing system that senses objects entering a predefined area.
[0009] Solution for solving the problem
[0010] An entry sensing system for sensing objects entering a predefined area, as described above, comprises: an entry sensing sensor for sensing the presence of a portion of the object within a predetermined range on a planar entry sensing surface; a silent sensor for sensing the object to invalidate detection by the entry sensing sensor, having a first unit and a second unit; and a control unit for controlling the operation of the entry sensing sensor based on the sensing result of the silent sensor, defining a direction orthogonal to the entry sensing surface as a passing direction, designating one side of the passing direction as a first passing direction side, and the other side as a second passing direction side. The first unit has a pair of first sensors on the first passing direction side relative to the entry sensing surface. The pair of first sensors are separately arranged opposite each other in a width direction parallel to the entry sensing surface. Each of the pair of first sensors senses the presence of the object within a predetermined first sensing range. A first sensing range extends from each of a pair of first sensors toward a direction in which the pair of first sensors are opposite each other in the width direction, and the pair of first sensing ranges are set to be separate from each other in the width direction. The second unit has a pair of second sensors on the second side of the passage direction relative to the entry sensing surface. The pair of second sensors are separately arranged opposite each other in the width direction. Each of the pair of second sensors senses whether the object exists within a predetermined second sensing range. The second sensing range extends from each of the pair of second sensors toward a direction in which the pair of second sensors are opposite each other in the width direction, and the pair of second sensing ranges are set to be separate from each other in the width direction. The control unit disables the entry sensing sensor when at least one of a first sensing state in which both of the pair of first sensors sense the object and a second sensing state in which both of the pair of second sensors sense the object is established.
[0011] According to this structure, silent sensors capable of sensing objects are provided on both a first side and a second side of the passage direction relative to the entry sensing surface. Therefore, an object approaching the entry sensing surface in the passage direction can be sensed using a silent sensor on one of the first or second sides of the passage direction before the object reaches the entry sensing surface. Furthermore, if a portion of the object remains on the entry sensing surface after it has completely passed the sensing range of the silent sensor on that side, the object can be sensed using the silent sensor on the other side. Therefore, if the sensed object is one that is permitted to pass through the entry sensing surface, the entry sensing sensor can be quickly deactivated before the object reaches the entry sensing surface, and can be appropriately deactivated during the period before the object passes through the entry sensing surface. Furthermore, according to this structure, the first sensor constituting the silent sensor is disposed on the first side of the passage direction relative to the entry sensing surface, and the second sensor is disposed on the second side of the passage direction relative to the entry sensing surface. That is, the sensing ranges of the first and second sensors do not intersect and are respectively set to be parallel to the entry sensing surface. Therefore, even in a relatively small setup space, it is easy to appropriately set the positional relationship along the passage direction between the sensing positions of the silent sensor and the entry sensor. Furthermore, a pair of first sensing ranges are set to be separated from each other in the width direction, and a pair of second sensing ranges are set to be separated from each other in the width direction. If neither of the first sensors nor the second sensors detects an object, the entry sensor will not be deactivated. Therefore, the entry sensor can be activated for objects that do not enter either of the first or second sensing ranges. Thus, the entry sensor can appropriately detect the passage of objects that are not permitted to enter. In this way, according to this structure, a technique can be provided to appropriately deactivate the sensing of permitted objects in an entry sensing system that senses objects entering a predefined area.
[0012] Further features and advantages of the access sensing system become apparent from the following description of exemplary and non-limiting embodiments illustrated with reference to the accompanying drawings. Attached Figure Description
[0013] Figure 1 This is a diagram illustrating an example of an item conveying device equipped with an entry sensing system;
[0014] Figure 2 This is a block diagram illustrating an example of the structure entering the sensing system;
[0015] Figure 3 This is an explanatory diagram showing an example of entering the sensing range of a sensing system;
[0016] Figure 4This is a diagram illustrating an example of the sensing range of a silent sensor in the width direction;
[0017] Figure 5 This is a diagram showing an example of the configuration position of the sensor system along the passing direction;
[0018] Figure 6 This is a timeline showing an example of entry into the sensing system;
[0019] Figure 7 This is a flowchart illustrating an example of entering a sensing system. Detailed Implementation
[0020] The following describes an implementation of the access sensing system based on the accompanying drawings. The access sensing system is installed in equipment (e.g., goods handling equipment or production equipment), which has a specific controlled area that restricts access to operators and others, and a general area with more lenient restrictions than the controlled area. Figure 1 An example of such equipment (here, conveying equipment 100) is schematically shown. Furthermore, Figure 2 The block diagram illustrates an example of the structure of the entry sensing system included in the conveying device 100. Furthermore, Figure 3 This illustrates an example of something entering the sensing range of a sensing system.
[0021] The conveying device 100 conveys items along a pre-set path R. Path R can be a tracked path formed by rails or the like, or a trackless path, for example, one set based on coordinates on the ground. Items are conveyed by an item transport vehicle (an example of object B). For example, if path R is trackless, an AGV (Automatic Guided Vehicle) is used as the item transport vehicle.
[0022] The conveying equipment 100 includes at least a general area E1 and a managed area E2. For example, the managed area E2 contains a warehouse for storing goods and production equipment that uses those goods for manufacturing. For instance, the warehouse may have an automatic transfer machine for moving goods between the warehouse and a goods transport vehicle, and the production equipment may have an automatic work machine. Therefore, generally, access to the managed area E2 is restricted, including to operators. In the event of a person mistakenly entering the managed area E2, for safety reasons, it is preferable to stop the operation of the automatic transfer machine or the automatic work machine. Therefore, the conveying equipment 100 includes an entry sensing system 10 that senses objects B entering the pre-defined area, i.e., the managed area E2. Figure 2 The management area control unit 9 shown can stop the operation of automatic transfer machines or automatic work machines in the management area E2 based on the sensing results of the entry sensing system 10 (especially the entry sensing sensor 5 described later).
[0023] like Figure 2 As shown, the entry sensing system 10 includes an entry sensing sensor 5, a silence sensor 3, and a control unit 7. The entry sensing sensor 5 senses object B, and the silence sensor 3 senses object B to invalidate the detection of object B by the entry sensing sensor 5. The control unit 7 controls the operation of the entry sensing sensor 5 based on the sensing result of the silence sensor 3. Figure 1 As shown, the entry sensing sensor 5 senses whether a portion of object B exists within a predetermined range on an entry sensing surface P that is set to be planar. In this embodiment, the entry sensing surface P is set to be orthogonal to the path R. Here, the direction orthogonal to the entry sensing surface P is defined as the passing direction Y, one side of the passing direction Y is defined as the first passing direction side Y1, and the other side is defined as the second passing direction side Y2. Furthermore, one of the directions orthogonal to the passing direction Y and parallel to the entry sensing surface P is defined as the width direction X. In this embodiment, the direction along the horizontal plane among the directions orthogonal to the passing direction Y is defined as the width direction X.
[0024] In this embodiment, the entry sensing sensor 5 is an optical sensor referred to as a light curtain. The entry sensing sensor 5 is configured such that an illuminator 51 with a plurality of illumination elements arranged in a row (see reference). Figure 3 (etc.), and a light receiver 52 having the same number of light-receiving elements as the lighting elements arranged in a row (see reference). Figure 3 The illuminators 51 and 52 are arranged relative to each other in the width direction X. The light illuminating the receiver 52 from the illuminator 51 forms the entry sensing surface P. When the object B blocks the light illuminating the receiver 52 from the illuminator 51, the entry sensing sensor 5 senses that a part of the object B exists on the entry sensing surface P.
[0025] like Figure 2 and Figure 3 As shown, the silent sensor 3 has a first unit 1 and a second unit 2. The first unit 1 has a pair of first sensors S1 (S1a, S1b) on a first side Y1 in the passage direction relative to the sensing surface P, and the pair of first sensors S1 (S1a, S1b) are separately arranged opposite each other in the width direction X. Furthermore, the second unit 2 has a pair of second sensors S2 (S2a, S2b) on a second side Y2 in the passage direction relative to the sensing surface P, and the pair of second sensors S2 (S2a, S2b) are separately arranged opposite each other in the width direction X. Figure 1 and Figure 3 As shown, each of a pair of first sensors S1 (S1a, S1b) senses whether object B exists within a predefined first sensing range K1. Similarly, each of a pair of second sensors S2 (S2a, S2b) senses whether object B exists within a predefined second sensing range K2.
[0026] like Figure 1 and Figure 3 As shown, the first sensing range K1 extends from each of a pair of first sensors S1 (S1a, S1b) in a direction opposite to each other along the width direction X. Furthermore, the first sensing range K1 is configured such that the pair of first sensing ranges K1 are separated from each other in the width direction X. Similarly, the second sensing range K2 extends from each of a pair of second sensors S2 (S2a, S2b) in a direction opposite to each other along the width direction X. Furthermore, the second sensing range K2 is configured such that the pair of second sensing ranges K2 are separated from each other in the width direction X.
[0027] The silent sensor 3 is composed of a sensor that senses the presence or absence of objects within a set distance range. The first unit 1 detects whether object B exists within a first sensing range K1 in a direction opposite to each of a pair of first sensors S1 (S1a, S2b) in the width direction X. Alternatively, the first unit 1 may be composed of a distance sensor that senses the distance from each of the pair of first sensors S1 (S1a, S2b) to object B when object B is present within the first sensing range K1. The second unit 2 is similar. In this embodiment, an ultrasonic sensor is used as the silent sensor 3. As described above, the entry sensing sensor 5 is an optical sensor. By making the sensing principles of the entry sensing sensor 5 and the silent sensor 3 different, interference between the two is eliminated, and reductions in sensing accuracy and false sensing are suppressed.
[0028] Here, as Figure 6 As shown, the state in which both first sensors S1 (S1a, S1b) sense object B, i.e., the state in which the first unit 1 senses object B, is called the first sensing state ST1. Furthermore, the state in which both second sensors S2 (S2a, S2b) sense object B, i.e., the state in which the second unit 2 senses object B, is called the second sensing state ST2. Additionally, the state in which the entry sensing sensor 5 senses object B is called the entry sensing state STW.
[0029] If at least one of the first sensing state ST1 and the second sensing state ST2 is in effect, the control unit 7 disables the entry sensing sensor 5. Here, "disabling" can mean either controlling the entry sensing sensor 5 to not sense object B, thus preventing it from entering a sensing state STW, or even if the entry sensing sensor 5 senses object B and enters a sensing state STW, the control unit 7 or the management area control unit 9 (see [reference]) will disable the entry sensing sensor 5. Figure 3 It also ignores the way the sensing state is displayed.
[0030] For example, such as Figure 6 As shown, when the first unit 1 senses object B at time t1, it enters the first sensing state ST1, and the control unit 7 disables the entry sensing sensor 5. Thereafter, even if the entry sensing sensor 5 senses object B at time t2 and enters the entry sensing state STW, the entry sensing sensor 5 is disabled because the first sensing state ST1 is established. At the subsequent time t3, the second unit 2 also senses object B, entering the second sensing state ST2. At time t4, object B passes through the first sensor S1, and the first sensing state ST1 is deactivated, but because the second sensing state ST2 is established, the disabling of the entry sensing sensor 5 continues.
[0031] At time t5, object B passes through the sensing surface P, and the entry sensing state STW is also deactivated. At a subsequent time t6, when object B also passes through the second sensor S2 and the second sensing state ST2 is deactivated, the entry sensing sensor 5 is activated. In this case, the period from time t1 to time t6, during which at least one of the first sensing state ST1 and the second sensing state ST2 is established, becomes a silent period M (first silent period M1), and the entry sensing sensor 5 is deactivated. Furthermore, it is preferable that, as in time t3 to time t4, there is a period during which the first sensing state ST1 and the second sensing state ST2 repeat, so that deactivation continues uninterruptedly during the period during which object B passes through the sensing surface P.
[0032] Furthermore, after the entry sensing sensor 5 stops detecting object B, i.e., after time t5, even if the entry sensing sensor 5 is not deactivated, object B will not be detected. If the time from time t5 to time t6 is long, the object B whose entry should be restricted (e.g., a person) may be able to follow the object TB that is allowed to enter the managed area E2 (see reference). Figure 4 (etc.) and enter. In this embodiment, the first passing direction separation distance F1 and the second passing direction separation distance F2 can be easily distinguished. The first passing direction separation distance F1 is the separation distance between the position of the first sensing range K1 in the passing direction Y and the entry sensing surface P (refer to...). Figure 5 The second separation distance F2 is the separation distance between the position of the second sensing range K2 in the Y direction and the entry sensing surface P (refer to...). Figure 5 ).
[0033] For example, preferably, the first passing direction separation distance F1 is set to a length that ensures sufficient time from sensing the object TB to deactivating the entry sensing sensor 5. Specifically, preferably, the position of the first sensing range K1 in the passing direction Y is set based on the sum of the time required for the first sensor S1 to sense and the time required from sensing to deactivation, and the moving speed of the transport vehicle carrying the object TB. The second passing direction separation distance F2 is preferably set based on the sensitivity of the entry sensing sensor 5 and the second sensor S2 such that the entry sensing sensor 5 does not sense the object TB at the earliest moment when the second sensor S2 does not sense it. Of course, the first passing direction separation distance F1 and the second passing direction separation distance F2 can also be the same.
[0034] Furthermore, the inter-unit separation distance F is set to be shorter than the length of the object TB along the passing direction Y, such that when at least one of the first sensing state ST1 and the second sensing state ST2 is established, the entry sensing sensor 5 is invalidated. The inter-unit separation distance F is the separation distance between the first unit 1 (first sensor S1) and the second unit 2 (second sensor S2) along the passing direction Y.
[0035] Thus, in this embodiment, silent sensors 3 are provided on both the first side Y1 and the second side Y2 of the passage direction relative to the entry sensing surface P. Therefore, the silent sensor 3 on one side (first unit 1) can detect the object B approaching the entry sensing surface P before the object B reaches the entry sensing surface P. Furthermore, after the object B has completely passed through the sensing range of the first unit 1, the silent sensor 3 on the other side (second unit 2) can detect the object B while at least a part of the object B is still present on the entry sensing surface P. Therefore, when the object B is an object TB that is allowed to pass through the entry sensing surface P, the entry sensing sensor 5 can be appropriately disabled, allowing the object TB to pass through the entry sensing surface P.
[0036] Furthermore, the first unit 1 and the second unit 2 are respectively configured such that their sensing ranges are parallel to the entry sensing surface P. Therefore, as described above, the positional relationship between the sensing position of the silent sensor 3 and the sensing position of the entry sensing sensor 5 along the passing direction Y can be easily and appropriately set. This ensures sufficient time from the moment the silent sensor senses the object TB that is allowed to enter until the entry sensing sensor 5 is deactivated, and also allows for an appropriate setting of the time until the entry sensing sensor 5 is deactivated.
[0037] Furthermore, in the sensing of the silent sensor 3, it is necessary to sense objects B, i.e., target objects TB, that are allowed to pass through and enter the sensing surface P. On the other hand, it is not necessary to sense objects B that restrict the passage of people, etc. Therefore, it is necessary to appropriately set the separation distance (width direction separation distance D) of the pair of first sensing ranges K1 in the width direction X, i.e., the first separation distance D1 (refer to...). Figure 3 ), and the separation distance (width direction separation distance D) of a pair of second sensing ranges K2 in the width direction X, i.e., the second separation distance D2 (refer to Figure 3 Since the object TB of the first unit 1 and the second unit 2 are the same, the first separation distance D1 and the second separation distance D2 can be the same value. For example, preferably, the first separation distance D1 and the second separation distance D2 are set based on the object width H, which is the length along the width direction X of the object TB that allows it to pass through the sensing surface P. Furthermore, the object width H is not limited to the width of the transport cart. When the transported item exceeds the width of the transport cart and is transported while protruding in the width direction X, the width of the transported item can also be set as the object width H.
[0038] However, errors sometimes occur when goods transport vehicles travel along path R. Specifically, positional offsets sometimes occur in the width direction X. Therefore, as... Figure 4 As shown, preferably, the first separation distance D1 and the second separation distance D2 are set based on the allowable offset width G, which is the range of allowable positional offset in the width direction X when the object TB moves along the passing direction Y.
[0039] For example, if the object TB is offset by a first allowable offset width G1 to one side of the width direction X, i.e., the first side X1 of the width direction, the sensing range of sensor S1b (and "S2b" of the second sensor S2) on one side of the pair of first sensors S1 (and the same applies to the second sensor S2) needs to be extended by "G1" on the first side X1 of the width direction. Similarly, if the object TB is offset by a second allowable offset width G2 to the other side of the width direction X, i.e., the second side X2 of the width direction, the sensing range of sensor S1a (and "S2a" of the second sensor S2) on the other side of the pair of first sensors S1 (and the same applies to the second sensor S2) needs to be extended by "G2" on the second side X2 of the width direction. That is, the sensing range K is extended by the allowable offset width G in the opposite direction of the pair of first sensors S1 (and the same applies to the second sensor S2), and the allowable offset width G is the sum of the first allowable offset width G1 and the second allowable offset width G2. Therefore, the first separation distance D1 and the second separation distance D2 are preferably set based on the allowable offset width G.
[0040] That is, the width separation distance D (first separation distance D1 and second separation distance D2) is set based on the object's width H and the allowable offset width G. Specifically, as follows... Figure 4 As shown, the width separation distance D (first separation distance D1 and second separation distance D2) is set to the length corresponding to the value obtained by subtracting the allowable offset width G from the object width H. Furthermore, since there is also an error in the object width H, the object width H in this case is preferably the smallest value within the allowable error range. Alternatively, relative to the standard value of the object width H, the maximum tolerance on the negative side is set to "α", and the width separation distance D is preferably set to the length obtained by subtracting the allowable offset width G and the maximum negative tolerance "α" from the object width H.
[0041] However, as Figure 5 As shown, the inter-unit separation distance F is set to be shorter than the length of the object TB along the passing direction Y, and the inter-unit separation distance F is as follows: Figure 5 The diagram shows the separation distance between the first unit 1 (first sensor S1) and the second unit 2 (second sensor S2) along the passing direction Y. This is so that, as described above, during the period when the object TB passes through the sensing surface P, the entry sensing sensor 5 is disabled as at least one of the first sensing state ST1 and the second sensing state ST2 is satisfied. On the other hand, it is preferable that the object B to be restricted from entering does not satisfy this condition. In most cases, it is considered that it is almost impossible for an object B, such as a person, to be restricted to be simultaneously sensed within the sensing range K of the pair of first sensors S1 or the pair of second sensors S2, but it is further preferred that it is not sensed simultaneously by the first unit 1 and the second unit 2. For example, the separation distance F between the units is set to be greater than the thickness of the person's body in the front-back direction, and the separation distance F between the units is the separation distance between the first unit 1 and the second unit 2 along the passing direction Y. Thus, when a person passes through the sensing surface P, a period occurs in which neither the first unit 1 nor the second unit 2 senses the person, thereby increasing the possibility of sensing the person's entry by the entry sensing sensor 5.
[0042] The following also refers to Figure 7 The flowchart is explained below. Control unit 7 first determines whether the invalidation condition (#1) is met. Here, refer to the above. Figure 6As described above, it is determined whether the first sensing state ST1 is when both of the first sensors S1 (S1a, S1b) sense object B. When the control unit 7 determines that it is the first sensing state ST1, it disables the entry sensing sensor 5 and starts a timer (#2). As described above, this disabling can either stop the function of the entry sensing sensor 5 or the control unit 7 can ignore the sensing result of the entry sensing sensor 5. Furthermore, if the sensing result of the entry sensing sensor 5 is directly transmitted to the management area control unit 9, the control unit 7 can also transmit a disabling message to the management area control unit 9 so that the entry sensing sensor 5 is ignored in the management area control unit 9.
[0043] Furthermore, a timer is set to reactivate the entry sensing sensor 5 after a timeout, considering safety, should the inactivation period exceed a specified time. For example, if the transport cart stops at the position sensed by the silent sensor 3 due to a malfunction, the sensing of the entry sensing surface P remains inactive. In this case, if the transport cart stops at the position sensed by the entry sensing sensor 5, it will be difficult for a person to enter the managed area E2 from the general area E1 because the transport cart also obstructs entry into the managed area E2. However, if the transport cart stops at a position ahead of the position sensed by the entry sensing sensor 5, the entrance will be open, making it easier for a person to enter the managed area E2 from the general area E1. Since the automated transfer machine or automated work machine is more likely to operate in the managed area E2, it is preferable to activate the entry sensing sensor 5 in such a situation.
[0044] When the control unit 7 disables the entry sensing sensor 5, it again determines whether the disabling condition (#3) is met. That is, it determines whether at least one of the following conditions is met: the first sensing state ST1 where both the first sensors S1 (S1a, S1b) sense the object B, and the second sensing state ST2 where both the second sensors S2 (S2a, S2b) sense the object B. If either the first sensing state ST1 or the second sensing state ST2 is met and the timer has not expired (#4), disabling continues. Figure 6 The time intervals t1 to t6). In the case where neither the first sensing state ST1 nor the second sensing state ST2 is valid ( Figure 6 After time t6 or when the timer expires (#4), the invalidation ends and the sensor 5 is reactivated (#5).
[0045] As described above, according to this embodiment, in the entry sensing system 10 that senses an object B entering a predefined area (management area E2), it is possible to appropriately disable the sensing of an object B (object TB) that is allowed to enter.
[0046] [Other Implementation Methods]
[0047] Other embodiments will be described below. Furthermore, the structures of each embodiment described below are not limited to individual application; they can also be combined with the structures of other embodiments, provided there is no contradiction.
[0048] (1) In the above example, the approach sensor 5 is an optical sensor and the silent sensor 3 is an ultrasonic sensor. However, it is also possible for the approach sensor 5 to be an ultrasonic sensor and the silent sensor 3 to be an optical sensor. Furthermore, if the approach sensor 5 and the silent sensor 3 have different sensing principles, a sensor using a sensing principle other than optical or ultrasonic can also be used.
[0049] (2) In the above, examples were given of different sensing principles for the entry sensing sensor 5 and the silence sensor 3. However, the entry sensing sensor 5 and the silence sensor 3 may also have the same sensing principle. For example, the entry sensing sensor 5 may be an optical light curtain and the silence sensor 3 may also be an optical distance sensor.
[0050] (3) In the above example, the separation distance F between the first unit 1 and the second unit 2 along the passing direction Y is shown to be greater than the thickness of the object to be restricted from entering, i.e., the human body, in the forward-backward direction. However, in the case of a human, the possibility of both of the first sensors or both of the second sensors simultaneously detecting the object is very low. Therefore, prioritizing efficiency, the separation distance F between the units can be set to be less than or equal to the thickness of the human body in the forward-backward direction.
[0051] (4) In the above, an example is given of a path R being formed along the horizontal plane and an entry point P being set along the vertical direction Z (see reference). Figure 1 However, the transport vehicle is not limited to moving in the horizontal direction; it can also move in the vertical direction. In this case, it can be positioned along the horizontal plane to enter the sensing surface P. In this case, any direction orthogonal to the passing direction Y can be used as the width direction X.
[0052] (5) In the above, examples and explanations are given as follows: Figure 6As shown in the first silent period M1, the first silent period M1 is set to disable the entry sensing sensor 5 when at least one of the first sensing state ST1 and the second sensing state ST2 is in effect. However, after the entry sensing sensor 5 stops sensing object B, that is, after time t5, object B is not sensed even if the entry sensing sensor 5 is not disabled. Therefore, the silent period M can also end at time t5 (second silent period M2). In this case, the control unit 7 disables the entry sensing sensor 5 when at least one of the first sensing state and the state that is both the entry sensing state STW and the second sensing state is in effect.
[0053] Compared to the determination in the first silence period M1, where only the silence sensor 3 determines whether silence is needed, in this case, the determination is based on the sensing results of both the silence sensor 3 (first unit 1, second unit 2) and the entry sensing sensor 5. Therefore, the system structure is slightly more complex. Furthermore, the second silence period M2 cannot be used if the entry sensing sensor 5's sensing function is rendered ineffective due to invalidation. However, by using the second silence period M2, the entry sensing sensor 5 can be quickly activated at times when silence is not required.
[0054] [Summary of Implementation Methods]
[0055] The following is a brief overview of the entry sensing system described above.
[0056] An entry sensing system is provided for sensing objects entering a predefined area. In a preferred embodiment, it comprises: an entry sensing sensor that senses whether a portion of the object exists within a predetermined range on a planar entry sensing surface; a silent sensor, which senses the object to invalidate detection by the entry sensing sensor, having a first unit and a second unit; and a control unit that controls the operation of the entry sensing sensor based on the sensing result of the silent sensor, defining a direction orthogonal to the entry sensing surface as a passing direction, designating one side of the passing direction as a first passing direction side, and the other side as a second passing direction side. The first unit has a pair of first sensors on the first passing direction side relative to the entry sensing surface. The pair of first sensors are separately arranged opposite each other in a width direction parallel to the entry sensing surface. Each of the pair of first sensors senses whether the object exists within a predetermined first sensing range. The first sensing range extends from each of the pair of first sensors toward the direction in which the pair of first sensors are opposite each other in the width direction, and the pair of first sensing ranges are set to be separated from each other in the width direction. The second unit has a pair of second sensors on the second side of the passage direction relative to the entry sensing surface. The pair of second sensors are arranged opposite each other separately in the width direction. Each of the pair of second sensors senses whether the object exists within a predetermined second sensing range. The second sensing range extends from each of the pair of second sensors toward the direction in which the pair of second sensors are opposite each other in the width direction, and the pair of second sensing ranges are set to be separated from each other in the width direction. The control unit disables the entry sensing sensor when at least one of a first sensing state in which both of the pair of first sensors sense the object and a second sensing state in which both of the pair of second sensors sense the object is established.
[0057] According to this structure, silent sensors capable of sensing objects are provided on both a first side and a second side of the passage direction relative to the entry sensing surface. Therefore, an object approaching the entry sensing surface in the passage direction can be sensed using a silent sensor on one of the first or second sides of the passage direction before the object reaches the entry sensing surface. Furthermore, if a portion of the object remains on the entry sensing surface after it has completely passed the sensing range of the silent sensor on that side, the object can be sensed using the silent sensor on the other side. Therefore, if the sensed object is one that is permitted to pass through the entry sensing surface, the entry sensing sensor can be quickly deactivated before the object reaches the entry sensing surface, and can be appropriately deactivated during the period before the object passes through the entry sensing surface. Furthermore, according to this structure, the first sensor constituting the silent sensor is disposed on the first side of the passage direction relative to the entry sensing surface, and the second sensor is disposed on the second side of the passage direction relative to the entry sensing surface. That is, the sensing ranges of the first and second sensors do not intersect and are respectively set to be parallel to the entry sensing surface. Therefore, even in a relatively small setup space, it is easy to appropriately set the positional relationship along the passage direction between the sensing positions of the silent sensor and the entry sensor. Furthermore, a pair of first sensing ranges are set to be separated from each other in the width direction, and a pair of second sensing ranges are set to be separated from each other in the width direction. If neither of the first sensors nor the second sensors detects an object, the entry sensor will not be deactivated. Therefore, the entry sensor can be activated for objects that do not enter either of the first or second sensing ranges. Thus, the entry sensor can appropriately detect the passage of objects that are not permitted to enter. In this way, according to this structure, a technique can be provided to appropriately deactivate the sensing of permitted objects in an entry sensing system that senses objects entering a predefined area.
[0058] Furthermore, preferably, the first separation distance and the second separation distance are set based on the object width and the allowable offset width. The first separation distance is the separation distance between a pair of first sensing ranges in the width direction, and the second separation distance is the separation distance between a pair of second sensing ranges in the width direction. The object width is the length of the object that is allowed to pass through the entry sensing surface along the width direction, and the allowable offset width is the range of positional offset allowed in the width direction when the object moves along the passing direction.
[0059] Based on this structure, the length of the object along the width direction and the positional offset of the object in the width direction during movement can be taken into account, and the first separation distance and the second separation distance can be appropriately set. Therefore, the object can be appropriately sensed by a silent sensor.
[0060] Furthermore, preferably, the first separation distance and the second separation distance are set to lengths corresponding to the values obtained by subtracting the allowable offset width from the width of the object.
[0061] According to this structure, even if the object and the object are offset in the width direction within the allowable offset width range, since the object also enters a pair of first sensing ranges and a pair of second sensing ranges, the object can be properly sensed by the silent sensor regardless of the object's position offset in the width direction.
[0062] Furthermore, preferably, the separation distance between the first unit and the second unit along the passing direction is greater than the thickness of the human body in the front-back direction.
[0063] The object restricted from passing through such an entry sensing surface is sometimes a person. In many cases, the length of the object allowed to pass through the entry sensing surface along the passing direction is greater than the thickness of the person's body in the front-back direction. Therefore, if either the first unit or the second unit senses an object, the entry sensing sensor is deactivated, thereby controlling the operation of the entry sensing sensor so that the allowed object can pass through appropriately. Moreover, since the first unit and the second unit are further separated along the passing direction than the thickness of the person's body in the front-back direction, a period occurs when a person passes through the entry sensing surface where neither the first unit nor the second unit senses the entry, thus increasing the likelihood that the entry of a person can be detected using the entry sensing sensor.
[0064] Furthermore, preferably, the entry sensing sensor and the silence sensor are sensors that use different sensing principles to sense the object.
[0065] For example, when both the access sensor and the silent sensor are optical sensors, the sensing accuracy of the silent sensor may sometimes decrease or false sensing may occur due to light reflected (including diffuse reflection) from objects passing through the sensing surface, such as the surface of a transport vehicle or fastening components like screws. Furthermore, in cases where the transport vehicle is an automated guided vehicle (AGV), optical obstacle sensors are often installed to prevent contact or collisions with workers or other objects. Since light illuminating such an obstacle sensor may enter the silent sensor, sensing accuracy may also decrease. Moreover, even when both the access sensor and the silent sensor are ultrasonic sensors, sensing accuracy may similarly decrease or false sensing may occur due to interference. As in this structure, if the sensing principle of the access sensor differs from that of the silent sensor, the aforementioned decrease in accuracy or false sensing is suppressed.
[0066] Furthermore, preferably, the entry sensing sensor is an optical sensor, and the silence sensor is an ultrasonic sensor.
[0067] Optical sensors are easy to set for sensing thin, planar surfaces. On the other hand, ultrasonic sensors tend to have a wider sensing range than optical sensors, thus enabling them to detect the presence or absence of objects within a certain extended range. Therefore, ultrasonic sensors are less affected by the shape of objects when sensing the presence of objects allowed to pass through the sensing surface. This prevents erroneous detection of objects that should be allowed to enter by the entry sensor due to the sensing delay of the silent sensor. Therefore, if the entry sensor is optical and the silent sensor is ultrasonic, the operation of the entry sensor can be appropriately controlled, and objects can be properly sensed on the entry sensing surface.
[0068] Explanation of reference numerals in the attached figures
[0069] 1: Unit 1
[0070] 2: Unit Two
[0071] 3: Silent Sensor
[0072] 5: Enter the sensor
[0073] 7: Control Department
[0074] 10: Entering the sensing system
[0075] B: Object
[0076] D: Separation distance in the width direction (separation distance in the width direction)
[0077] D1: First separation distance
[0078] D2: Second separation distance
[0079] E2: Management Area (Pre-defined area)
[0080] F: Inter-unit separation distance (separation distance along the passing direction)
[0081] G: Allowed offset width
[0082] H: Object width
[0083] K: Sensing range
[0084] K1: First sensing range
[0085] K2: Second sensing range
[0086] P: Entering the sensing surface
[0087] S1: First sensor
[0088] S2: Second sensor
[0089] ST1: First Sensing State
[0090] ST2: Second Sensing State
[0091] TB: Object
[0092] X: Width direction
[0093] Y: Direction
[0094] Y1: Passing through the first side of the direction
[0095] Y2: Passing through the second side of the direction.
Claims
1. An entry sensing system for sensing an object entering a predetermined area, wherein, The entry sensing system includes: An entry sensing sensor detects whether a portion of the object exists within a predetermined range on a planar entry sensing surface. A silent sensor is a sensor that senses an object to invalidate the detection of the object by the entry sensing sensor, and has a first unit and a second unit. as well as The control unit controls the action of the entering sensor based on the sensing results of the silent sensor. The direction orthogonal to the sensing surface is defined as the passing direction, one side of the passing direction is defined as the first passing direction side, and the other side is defined as the second passing direction side. The first unit has a pair of first sensors on the first side of the passage direction relative to the entry sensing surface. The pair of first sensors are separately arranged opposite each other in the width direction, which is a direction parallel to the entry sensing surface. Each of the pair of first sensors senses whether the object exists within a predetermined first sensing range. The first sensing range extends from each of the pair of first sensors toward a direction in which the pair of first sensors are opposite each other in the width direction, and the pair of first sensing ranges are set to be separate from each other in the width direction. The second unit has a pair of second sensors on the second side of the passage direction relative to the entry sensing surface, and the pair of second sensors are separately arranged opposite each other in the width direction. Each of the pair of second sensors senses whether the object exists within a predefined second sensing range. The second sensing range extends from each of the pair of second sensors toward the direction in which the pair of second sensors are opposite each other in the width direction, and the pair of second sensing ranges are set to be separated from each other in the width direction. The control unit disables the entry sensing sensor when at least one of a first sensing state in which both of the pair of first sensors sense the object and a second sensing state in which both of the pair of second sensors sense the object is established.
2. The entry sensing system according to claim 1, wherein, The first separation distance and the second separation distance are set based on the object width and the allowable offset width. The first separation distance is the separation distance between a pair of first sensing ranges in the width direction, and the second separation distance is the separation distance between a pair of second sensing ranges in the width direction. The object width is the length of the object that is allowed to pass through the entry sensing surface along the width direction, and the allowable offset width is the range of positional offset allowed in the width direction when the object moves along the passing direction.
3. The entry sensing system according to claim 2, wherein, The first separation distance and the second separation distance are set to lengths corresponding to the values obtained by subtracting the allowable offset width from the width of the object.
4. The entry sensing system according to any one of claims 1 to 3, wherein, The separation distance between the first unit and the second unit along the passing direction is greater than the thickness of the human body in the front-back direction.
5. The entry sensing system according to any one of claims 1 to 3, wherein, The entry sensor and the silence sensor are sensors that use different sensing principles to sense the object.
6. The entry sensing system according to claim 5, wherein, The entry sensing sensor is an optical sensor, and the silence sensor is an ultrasonic sensor.