Parking device

Abstract

To provide a parking device that reduces the likelihood of battery depletion in a detector and offers high reliability.SOLUTION: A parking device according to one embodiment comprises: a plurality of detectors installed on a plurality of pallets capable of loading vehicles; and a controller communicating with each of the detectors. The detectors initiate transmission of a survival signal to the controller according to transmission start conditions. The controller transmits a response signal specifying the restart time at which the detector corresponding to the received survival signal next initiates transmission of a survival signal. The detector terminates transmission of the survival signal according to transmission termination conditions. The transmission start conditions include either the arrival of a predetermined restart time prescribed for each detector in advance or the arrival of a restart time specified by the response signal received by the detector for itself. The transmission termination conditions include the reception by the detector of the response signal for itself.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] One embodiment of the present disclosure relates to a parking device for parking a vehicle such as an automobile. [Background technology]

[0002] A conventional vehicle parking system is a so-called multi-level parking system in which vehicles are placed on pallets and parked in a stacked manner. In the multi-level parking system, the pallets are raised and lowered vertically or moved laterally horizontally to allow vehicles to enter and exit the parking system from the entrance and exit gate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-121910 Summary of the Invention [Problem to be solved by the invention]

[0004] In multi-level parking systems, vehicles may move and come into contact with parts of the system when entering or leaving the system, or the pallets may tilt from a horizontal position. For this reason, communication is performed between the pallets and the control device to check whether there are any abnormalities with the pallets.

[0005] Patent Document 1 describes a system for remotely monitoring abnormalities that occur on pallets. The system described in Patent Document 1 operates by receiving power from a battery and includes a monitoring pallet equipped with sensors, cameras, etc., and a monitoring device that monitors the monitoring pallet. The monitoring pallet and monitoring device of the system described in Patent Document 1 are connected via a wireless network line, and data for detecting abnormalities is constantly exchanged.

[0006] In this type of system, signals are constantly exchanged via a wireless network, so repeated signal transmissions tend to drain the battery in the monitoring pallet, and the monitoring pallet may stop transmitting signals due to battery exhaustion. As such, the system described in Patent Document 1 has the problem of being unreliable because the battery is prone to running out.

[0007] In view of the above problem, one object of one embodiment of the present disclosure is to provide a parking device that is highly reliable and in which the detection device is less likely to run out of battery power. [Means for solving the problem]

[0008] A parking device according to one embodiment of the present disclosure includes a plurality of detection devices installed on a plurality of pallets on which vehicles can be placed, and a control device that communicates with each of the detection devices, wherein the detection devices start repeating transmission of a survival signal to the control device in accordance with a transmission start condition, the control device transmits a response signal that specifies the restart time at which the detection device corresponding to the received survival signal will next start repeating transmission of the survival signal, and the detection devices stop repeating transmission of the survival signal in accordance with a transmission stop condition, wherein the transmission start condition includes the arrival of either a restart time predetermined for each detection device or a restart time specified by a response signal received by the detection device for itself, and the transmission stop condition includes the detection device receiving a response signal for itself. [Effects of the Invention]

[0009] According to one embodiment of the present disclosure, a parking device can be provided that is less likely to experience battery drain in the detection device and is highly reliable. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic side view showing the configuration of a parking device according to an embodiment of the present disclosure. FIG. [Figure 2] FIG. 2 is a schematic front view showing the configuration of the parking device shown in FIG. [Figure 3]2 is an explanatory diagram showing the connection between a control device and a detection device included in the parking device shown in FIG. 1. [Figure 4] FIG. 2 is a block diagram of the parking device shown in FIG. [Figure 5] 5 is a flowchart illustrating processing performed in a control unit of the detection device shown in FIG. [Figure 6] 2 is a diagram showing an example of a data structure used in the parking device shown in FIG. 1. [Figure 7] 1. FIG. 4 is a diagram showing an example of another data structure used in the parking device shown in FIG. [Figure 8] 5 is a flowchart illustrating processing performed in a control unit of the control device shown in FIG. [Figure 9] 2 is a diagram illustrating an example of allocating time slots to detection devices included in the parking device shown in FIG. 1. FIG. [Figure 10] 5 is a diagram illustrating the timing of communication between the control device and the detection device shown in FIG. 4. FIG. [Figure 11] 5 is another diagram illustrating the timing of communication between the control device and the detection device shown in FIG. 4. FIG. [Figure 12] 10A and 10B are diagrams illustrating timing of communication between a control device and a detection device according to a comparative example. [Figure 13] FIG. 10 is a block diagram of a parking device according to another embodiment of the present disclosure. [Figure 14] 14 is a flowchart illustrating processing performed in a control unit of the detection device shown in FIG. [Figure 15] FIG. 14 is a diagram showing an example of a data structure used in the parking device shown in FIG. [Figure 16] 10 is a diagram illustrating the timing of communication between a control device and a detection device included in a parking device according to a comparative example. FIG. [Figure 17] 14 is a diagram illustrating the timing of communication between the control device and the detection device shown in FIG. 13. FIG. [Figure 18] 14 is a diagram illustrating an example of a method for correcting a counter used between the control device and the detection device shown in FIG. 13. FIG. [Figure 19] FIG. 10 is a block diagram of a parking device according to a modified example of the present disclosure. [Figure 20] 20 is a flowchart illustrating processing performed in a control unit of the detection device shown in FIG. [Figure 21] FIG. 10 is a block diagram of a parking device according to another modified example of the present disclosure. [Figure 22] 22 is a flowchart illustrating processing performed in a control unit of a control device included in the parking device shown in FIG. 21. [Figure 23] 22 is a flowchart illustrating processing performed in a control unit of a detection device included in the parking device shown in FIG. 21. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, in this specification and each drawing, elements that are identical or similar to those previously described with reference to the previous drawings may be designated by the same reference numerals (or numbers followed by a, b, A, B, etc.), and detailed descriptions may be omitted as appropriate. Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element and have no further meaning unless otherwise specified.

[0012] In this specification, when a component or region is described as being "on (or under)" another component or region, unless otherwise specified, this includes not only the case where it is directly above (or directly under) the other component or region, but also the case where it is above (or under) the other component or region, i.e., the case where another component is included between the component or region and above (or under) the other component or region.

[0013] Furthermore, in this specification, unless otherwise specified, expressions such as "α includes A, B, or C," "α includes any one of A, B, and C," and "α includes one selected from the group consisting of A, B, and C" do not exclude cases where α includes multiple combinations of A to C. Furthermore, these expressions do not exclude cases where α includes other elements.

[0014] First Embodiment 1. Overview of the parking system FIG. 1 is a schematic side view showing the configuration of a parking device 100 according to an embodiment of the present disclosure. FIG. 2 is a schematic front view showing the configuration of a parking device 100 according to an embodiment of the present disclosure. FIGS. 1 and 2 show the main configuration of a parking device 100 according to an embodiment of the present disclosure. In this specification, the side of the parking device 100 where the entrance and exit gates are located will be referred to as the front, and the opposite side will be referred to as the back. The direction from the front to the back of the parking device 100, i.e., the direction in which a vehicle V enters the parking device 100, will be referred to as the front-to-back direction (-x direction). The y direction is the direction from the front to the back of the drawing in FIG. 1 (the left-right direction of the vehicle V), and the z direction is the direction from bottom to top in FIG. 1 (the up-down direction, or lifting and lowering direction of the vehicle V).

[0015] Parking device 100 is a multi-story parking device that can park multiple vehicles V. Parking device 100 has a skeletal structure mainly composed of multiple support pillars 102 and beams 103 erected between the support pillars 102, and has multiple compartmented vehicle storage areas that can accommodate one vehicle V. Parking device 100 is equipped with a pallet 104 on which vehicle V is placed.

[0016] In this embodiment, the parking device 100 has, as an example, four vertical tiers (lifting direction) in which the vehicles V are stacked, and four horizontal tiers in which the vehicles V are arranged side by side. The parking device 100 requires spare space for the vehicles V to be lifted, lowered, or moved sideways. Excluding the spare space, the parking device 100 can park and accommodate a maximum of 13 vehicles V. In other words, the parking device 100 has 13 vehicle loading areas indicated by PS1 to PS13. Pallets 104 on which the vehicles V are placed are installed in each vehicle loading area.

[0017] The parking device 100 of this embodiment is not limited to the structure shown in Figures 1 and 2. The parking device 100 may have a structure with fewer than four rows or five or more rows in the vertical direction, and may have a structure with fewer than four rows or five or more rows in the horizontal direction.

[0018] In the parking device 100, the pallet 104 is raised and lowered in the vertical direction and moved horizontally in the horizontal direction, thereby moving the target pallet 104 to the entrance / exit gate and allowing the vehicle V to be loaded or unloaded.

[0019] The parking apparatus 100 shown in FIGS. 1 and 2 parks a vehicle V by raising and lowering one to four tiers of pallets 104. However, the method by which the parking apparatus 100 parks a vehicle V is not limited to the method shown in FIGS. 1 and 2. The parking apparatus 100 may park a vehicle by applying various methods as follows. For example, a method may be used in which two to four tiers of pallets 104 are raised and lowered to the first tier of the parking apparatus 100, where no pallets 104 exist. Alternatively, a method may be used in which the first tier of the pallet 104 of the parking apparatus 100 is lowered into an underground pit, and the second to fourth tiers of pallets 104 are lowered to the first tier. Furthermore, a method may be used in which the first to third tiers of pallets 104 are slid forward and backward, and the second to fourth tiers of pallets 104 are lowered to the first tier. Furthermore, a method may be used in which these methods are combined.

[0020] As shown in FIG. 1 , the pallet 104 may be provided with a car stopper 105 that prevents the vehicle V from moving toward the rear side. The car stopper 105 defines a parking area on the pallet 104 in the direction of travel of the vehicle V. The car stopper 105 is provided on the rear side of the pallet 104. The height of the car stopper 105 is lower than the height of the vehicle V. The car stopper 105 comes into contact with the rear wheels of the vehicle V to prevent the vehicle V from moving toward the rear side of the parking device 100, thereby preventing the vehicle V from protruding outside the pallet 104. When the vehicle V enters the parking device 100 from the front side of the vehicle V, the car stopper 105 may come into contact with the front wheels of the vehicle V to prevent the vehicle V from moving toward the rear side of the parking device 100.

[0021] The pallet 104 is provided so that it can be raised and lowered along the support columns 102 by an elevator 106. The pallet 104 is also provided so that it can move horizontally (y direction). The pallet 104 may move along a horizontal guide rail (not shown) that is provided parallel to the horizontal direction. When multiple vehicles V are stacked in the z direction (vertical direction) in the framework structure, the pallets 104 are arranged at intervals that prevent adjacent vehicles V from interfering with each other in the vertical direction.

[0022] The parking device 100 is operated by an operation panel 208. The operation panel 208 is provided on the outside of the parking device 100. As an example, as shown in FIG. 1, the operation panel 208 may be attached to a support 102 near the entrance / exit gate of the parking device 100 (lower right side of the figure).

[0023] The operation panel 208 communicates via wired or wireless means with the control device 200 that controls the parking device 100. The control device 200 receives instructions from the user via the operation panel 208 regarding the entry and exit of the vehicle V, and controls all operations of the parking device 100, such as the raising and lowering of the multiple pallets 104. Note that FIG. 1 shows an example in which the control device 200 is attached to the back of the parking device 100.

[0024] The entrance / exit gate for vehicle V is provided on one level (ground level) of parking apparatus 100. Although not shown, a gate may be installed at the entrance / exit gate of parking apparatus 100. When vehicle V leaves the parking apparatus, the gate is opened when pallet 104 is moved to the entrance / exit gate, and is closed by operating operation panel 208 to close the gate after vehicle V has left. When vehicle V enters the parking apparatus, the gate is opened by operating operation panel 208 to open the gate, and is closed by operating operation panel 208 after vehicle V has entered the parking apparatus. Closing the gate normally prevents people from entering the parking apparatus 100. In this case, to ensure safety when closing the gate, a sensor may be attached to detect objects (people or objects) in a predetermined area in the closing direction of the gate. Such a sensor may be attached to support post 102, the gate, or the like near the entrance / exit gate of parking apparatus 100 (lower right side of the figure). Although not shown, a notification unit may be provided to notify users when the gate is closed or opened.

[0025] The parking apparatus 100 is equipped with a detection device 300 that detects vibrations and tilt of the pallet 104 when the pallet 104 is raised or lowered. In this embodiment, the detection device 300 is attached to the surface (back surface) of each plate-shaped pallet 104 opposite the surface (front surface) on which the vehicle V is placed. However, the location where the detection device 300 is placed is not limited to the back surface of each pallet 104. The detection device 300 may also be placed on the front surface of each pallet 104. In this case, the detection device 300 is placed in a position where it does not come into contact with the vehicle V. For example, when the detection device 300 is placed on the front surface of the pallet 104, it may be placed behind the car stopper 105.

[0026] 2. Connection between the control device and the detection device As shown in Fig. 3, the parking device 100 includes one control device 200 and multiple detection devices 300. Each detection device 300 is installed on a respective pallet 104 and moves together with the pallet 104. The pallets 104 and the control device 200 are connected by drive elements DE including, for example, the elevator 106 shown in Fig. 1 and a pallet drive device 107 described below, and are raised and lowered or moved laterally under the control of the control device 200. The detection devices 300 and the control device 200 are also connected by a wireless path WP including, for example, a communication path conforming to a low-power wireless communication standard, and are capable of communicating with each other.

[0027] Next, to facilitate understanding, the schematic configuration of the parking device 100 according to one embodiment of the present disclosure will be described by showing the control device 200 and one of the multiple detection devices 300 shown in Fig. 3. Hereinafter, the control device 200 may be referred to as the "parent device" and the detection device 300 as the "child device."

[0028] 3. Overview of the control device and detection device 3-1.Control device As shown in FIG. 4, the control device 200 includes a memory unit 212 that stores various data, a control unit 214 that controls each unit, a communication unit 216 that communicates with other devices, and a time counter 218 that measures time.

[0029] The storage unit 212 is a logical storage area, and includes, for example, memories such as a main storage device, a secondary storage device, and a storage area inside a central processing unit (CPU). The storage unit 212 includes storage devices such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage unit 212 stores programs and the like that cause the control device 200 to realize various functions. The storage unit 212 also temporarily stores data that cause the control device 200 to realize various functions.

[0030] The control unit 214 is, for example, a CPU. The control unit 214 realizes various functions described below by executing programs stored in the storage unit 212, but the configuration for realizing the control device 200 is not limited to this. The programs executed by the control unit 214 may be provided in a state where they are stored in a computer-readable recording medium such as a magnetic recording medium, an optical recording medium, a magneto-optical recording medium, or a semiconductor memory. Furthermore, each program may be downloaded via a network.

[0031] The control unit 214 transmits instruction signals related to the driving of the pallets 104 to the pallet driving device 107. The control unit 214 transmits signals related to the driving of the pallets 104 to the pallet driving device 107 based on information received from the operation panel 208, and controls the driving of the pallets 104 via the driving elements DE. The control unit 214 receives signals indicating the acceleration and inclination of the pallet 104 corresponding to the detection device 300 via the wireless path WP from the detection device 300 arranged on each pallet 104, and performs predetermined control based on the received signals.

[0032] When the value of acceleration detected by the detection device 300 attached to the moving pallet 104 exceeds a predetermined threshold, the control unit 214 may send an instruction signal to the pallet driving device 107 to stop the movement of the pallet 104. Furthermore, the control unit 214 may send an instruction signal to the pallet driving device 107 to keep the pallet 104 horizontal, depending on the value of the tilt detected by the detection device 300.

[0033] The programs executed by the control unit 214 may be provided in a state stored in a computer-readable recording medium such as a magnetic recording medium, an optical recording medium, a magneto-optical recording medium, a semiconductor memory, etc. Furthermore, each program may be downloaded via a network.

[0034] Based on the control of the control unit 214, the communication unit 216 transmits and receives data to and from other devices including the detection device 300, the pallet driving device 107, and external devices not shown, and receives information input to the operation panel 208.

[0035] The time counter 218 is, for example, a counter including a crystal oscillator and a frequency divider circuit, but may have other configurations. For example, the time counter 218 may be a clock including a radio-controlled clock.

[0036] The operation panel 208 is a user interface through which a user inputs instructions for automatic operations (such as specifying the number of the pallet 104) to the control device 200, and is connected to the control device 200. When the operation panel 208 receives input for automatic operations, such as pressing a button or touching a panel, it transmits the input information to the control device 200.

[0037] 3-2.Detection device The detection device 300 includes a detection unit 312 that detects the acceleration and inclination of the pallet 104, a memory unit 314 that stores various data, a control unit 316 that controls each unit, a communication unit 318 that communicates with other devices, a battery 320 that supplies power to each unit of the detection device 300, and a time counter 322 that measures time. The detection device 300 is attached to the pallet 104. The configurations of the memory unit 314, the control unit 316, and the communication unit 318 are similar to, for example, the memory unit 212, the control unit 214, and the communication unit 216 of the control device 200.

[0038] The detection device 300 has a communication state that indicates whether communication with other devices is possible, and can be switched at least between enabled and disabled. The detection device 300 detects the acceleration and tilt of the pallet 104 to which it is attached, and can transmit the detection results to the control device 200 while the communication state is enabled. The power consumption of the detection device 300 is kept lower when the communication state is disabled than when the communication state is enabled. Even when the communication state is disabled, the detection device 300 can always measure at least the acceleration of the pallet 104 using an acceleration sensor. The detection device 300 can be realized, for example, by hardware including a circuit that cuts off the power supply to the communication unit 318 (described later) according to a bit value set in a control register.

[0039] The detection unit 312 includes, for example, a sensor that detects the acceleration and tilt of the pallet 104. The sensor that detects the acceleration of the pallet 104 is, for example, a triaxial acceleration sensor. The sensor that detects the tilt of the pallet 104 is, for example, a triaxial gyro sensor. Note that the sensors included in the detection unit 312 are not limited to triaxial acceleration sensors and triaxial gyro sensors, and may include, for example, a magnetic sensor, as long as they are capable of detecting the state and changes in the state of the pallet 104.

[0040] The three-axis acceleration sensor of the detection unit 312 continuously detects acceleration and outputs a signal indicating the detected acceleration, regardless of whether the communication state of the detection device 300 is enabled or disabled. In contrast, the three-axis gyro sensor of the detection unit 312 is activated when the three-axis acceleration sensor detects vibration of the pallet 104. While activated, the three-axis gyro sensor detects the orientation of the pallet 104 and outputs a signal indicating the detected tilt. The three-axis acceleration sensor and the three-axis gyro sensor of the detection unit 312 may be a packaged six-axis sensor module. The detection device 300 may have a power consumption switching state in addition to the communication state as a state of the detection device 300. For example, the communication state may be set to disabled when the detection device 300 is in a low power consumption state such as a sleep state, and the communication state may be set to enabled when the detection device 300 is in a high power consumption state such as an activated state.

[0041] The storage unit 314 is a logical storage area, and includes, for example, memory such as a main storage device, a secondary storage device, and a storage area inside the CPU. The storage unit 314 includes storage devices such as RAM and ROM. The storage unit 314 stores programs and the like that cause the detection device 300 to realize various functions. The storage unit 314 also temporarily stores data that cause the detection device 300 to realize various functions.

[0042] The control unit 316 is, for example, a CPU. The control unit 316 executes programs stored in the storage unit 314 to realize various functions described below, but the configuration for realizing the detection device 300 is not limited to this. The programs executed by the control unit 316 may be provided in a state stored in a computer-readable storage medium such as a magnetic storage medium, an optical storage medium, a magneto-optical storage medium, or a semiconductor memory. Alternatively, each program may be downloaded via a network. The control unit 316 controls the transmission of signals to the control device 200, including data related to the control unit itself and data related to the status of the pallet 104 detected by the detection unit 312. The control unit 316 also controls the switching of the communication state between enabled and disabled and the determination of whether to start repeated communication, based on data included in the signals received from the control device 200.

[0043] The communication unit 318 transmits and receives data and signals to and from the control device 200 based on the control of the control unit 316. The communication unit 318 may also transmit and receive data and signals to and from the detection device 300 installed on another pallet 104 based on the control of the control unit 316. The communication unit 318 transmits and receives data and signals via the wireless path WP.

[0044] The pallet driving device 107 includes, for example, gears, chains, etc. Based on instruction signals relating to the driving of the pallets 104 received from the control unit 214, the pallets 104 are driven to move up and down or to move laterally.

[0045] 4. Regular communication Continuing to refer to Fig. 4, the scheduled communication between the detection device 300 and the control device 200 will be described. The detection device 300 transmits and receives signals to and from the control device 200. The detection device 300 starts repeatedly transmitting information about itself when a transmission start condition, which is a condition for starting transmission, is satisfied. The detection device 300 stops transmitting information about itself when a transmission stop condition, which is a condition for stopping transmission, is satisfied.

[0046] The call start condition is, for example, the arrival of the time to resume calls. The call restart time, which is the time to resume calls, may be one or more times stored in the storage unit 314, or may be specified by the control device 200. As will be described later, the call restart time is predetermined and different for each detection device 300, or is specified by the control device 200. Because each detection device 300 starts calls at approximately the same time, this communication is called scheduled communication.

[0047] The transmission stop condition is that the detection device 300 receives a signal transmitted by the control device 200 to the detection device itself. The control device 200 may determine that an abnormality has occurred in the detection device 300 when it does not receive a signal transmitted from the detection device 300 even after a certain time has elapsed since the reference time point (for example, the time it takes for scheduled communication to complete for all of the detection devices 300). The reference time point is, for example, a transmission restart time predetermined for each detection device 300 or a transmission restart time specified by the control device 200.

[0048] Next, the flow of the scheduled communication process of the detection device 300 will be described with reference to the block diagram shown in Fig. 4 and the flowchart shown in Fig. 5. The control unit 316 of the detection device 300 repeats steps S101 to S105 shown in Fig. 5. The process is roughly divided into determining whether or not the call start condition is met (S101) and scheduled communication (S102 to S105). Each step will be described in detail below.

[0049] The process shown in FIG. 5 starts, for example, when the power to the detection device 300 is turned on, but the trigger for starting is not limited to turning on the power, and broadly includes cases where the control unit 316 returns from a state in which no processing is being performed to a state in which processing is being performed.

[0050] First, the control unit 316 determines whether the restart time has arrived (S101). For example, the control unit 316 determines that the restart time has arrived when the value of the time counter 322 is equal to or greater than the value of the restart time stored in the storage unit 314 (S101; Yes). For example, the control unit 316 does not determine that the restart time has arrived when the value of the time counter 322 is smaller than the restart time stored in the storage unit 314 (S101; No).

[0051] When the control unit 316 determines that the restart time has arrived (S101; Yes), it transmits an alive signal (S102).

[0052] The alive signal is a signal including a data structure exemplified in Fig. 6. The alive signal includes a unique identifier (ID) that can distinguish each of the detection devices 300 shown in Fig. 4 from one another.

[0053] The data structure of a signal refers to the structure of data that can be restored or read from the signal. The signal is, for example, transmitted by low-power wireless communication. There are no particular limitations on the modulation method, analog / digital type, whether data is coded or encrypted, or the method used. The same applies to signals other than the alive signal. For this reason, certain data and data structures may hereinafter be simply referred to as "signals."

[0054] 4 and 5, the control unit 316 waits for a predetermined time (S103). For example, the control unit 316 may wait until the difference between the current value of the time counter 322 and the value of the time counter 322 at the time of transmitting the alive signal (S102) reaches a predetermined value. The time for which the control unit 316 waits is a time long enough to receive a response signal, which will be described later in the next step. The time for which the control unit 316 waits is, for example, the sum of the time it takes the control device 200 to process the alive signal, the time it takes the control device 200 to transmit the response signal, and the time it takes the detection device 300 to detect the response signal.

[0055] After waiting for a predetermined time (S103), the control unit 316 determines whether or not a response signal directed to the device itself has been received (S104). The response signal is a signal having a data structure exemplified in FIG. 7. The response signal includes the ID of the detecting device 300 that transmitted the alive signal, and a transmission restart count that the control device 200 specifies for each detecting device 300 as the time for the next scheduled communication. For example, if the time for the next scheduled communication of a detecting device with an ID of 1 is specified after 100 counts, the data structure of the response signal has an ID of "1" and a transmission restart count of "100".

[0056] 4 and 5, the parking apparatus 100 includes a plurality of detection devices 300. Therefore, the response signal transmitted by the control device 200 may be received by detection devices 300 other than the detection device 300 that transmitted the alive signal. The response signal specifies the time of the next scheduled communication of the detection device 300 that transmitted the alive signal. Therefore, for example, if the ID included in the received response signal is the ID of the detection device 300 itself, the control unit 316 determines that the response signal addressed to the device itself has been received (S104; Yes). For example, if the ID included in the received response signal is not the ID of the device itself, the control unit 316 does not determine that the response signal addressed to the device itself has been received (S104; No).

[0057] When the control unit 316 determines that it has received a response signal addressed to itself (S104; Yes), it stores the transmission restart count included in the response signal in the memory unit 314 as the value of the restart time, and stops transmitting the alive signal (S105). After stopping the transmission of the alive signal, the control unit 316 returns the control flow to the beginning and continues the process from step S101. The control unit 316 is configured to restart the repeated transmission of the alive signal in accordance with the restart time stored in the memory unit 314, and the restart time is specified by the control device 200.

[0058] The control unit 316 of the detection device 300 processes scheduled communication in the manner described above. In contrast, the flow of scheduled communication processing by the control unit 214 of the control device 200 will be described with reference to the block diagram shown in FIG. 4 and the flowchart shown in FIG. 8.

[0059] The processing shown in FIG. 8 starts, for example, when the control device 200 is turned on, but the trigger for starting is not limited to turning on the power, and broadly includes cases where the control unit 214 returns from a state in which no processing is being performed to a state in which processing is being performed.

[0060] First, the control unit 214 determines whether or not a live signal (S102 in FIG. 5) transmitted from the communication unit 318 of the detection device 300 has been received (S201).

[0061] When the control unit 214 determines that an alive signal has been received (S201; Yes), it calculates the restart time of the detecting device 300 corresponding to the received alive signal (S202). Details of the calculation of the restart time so that the restart times of multiple detecting devices 300 do not overlap will be described later. When the control unit 214 does not determine that an alive signal has been received (S201; No), it continues to determine whether or not an alive signal has been received.

[0062] After calculating the restart time of the detecting device 300 corresponding to the received alive signal (S202), the control unit 214 transmits a response signal including the restart time calculated in S202 (S203). The response signal is a signal that specifies the restart time at which the detecting device 300 corresponding to the received alive signal will next start repeating the transmission of the alive signal. After executing S203, the control unit 214 returns the flow of control to the beginning and continues processing.

[0063] The control unit 214 of the control device 200 performs the scheduled communication process according to the flow described above. In this way, the control unit 214 repeatedly transmits a response signal including the ID of the detection device 300 that transmitted the alive signal each time it receives a live signal transmitted from any of the detection devices 300 included in the parking device 100.

[0064] 5. Allocating non-overlapping scheduled communication time slots The calculation of the resumption time (S202 in FIG. 8) so that the resumption times differ among the multiple detection devices 300 (see FIG. 4) is performed by, for example, as described below, assigning fixed, non-overlapping scheduled communication time slots to each detection device 300. Specifically, if the parking device 100 (see FIG. 4) includes N detection devices 300 and scheduled communication for all N detection devices 300 completes in P minutes, each detection device 300 can be assigned a (P / N)-minute time slot for scheduled communication. The resumption time is the start time of the assigned time slot. The assignment to each detection device 300 may be in order of the ID of each detection device 300, for example.

[0065] Figure 9 shows an example of allocation in which scheduled communications among three detection devices 300 completes in 60 minutes. In Figure 9, time passes from top to bottom of the drawing. For ease of understanding, one count by the time counter 218 or the time counter 322 (see Figure 4) is considered to be equal to one minute, and minutes may be simply indicated by the number of counts.

[0066] Since (P / N) is (60 / 3)=20, the time slot allocated to each detection device 300 is 20 minutes (count). If the IDs of the three detection devices 300 are "1" to "3", each of the 20-minute time slots is allocated to the detection devices 300 corresponding to IDs "1" to "3".

[0067] If one time slot of the detection device 300 with ID "1" starts from 0:00, the next time slot of the detection device 300 with ID "1" is from 1:00 to 1:20. If the control device 200 receives an alive signal emitted by the detection device 300 with ID "1" at 0:05, the start of the next time slot of the detection device 300 with ID "1" is 1:00, so the control device 200 (see FIG. 4) calculates a restart count corresponding to 55 minutes from the difference between 1:00 and 0:05.

[0068] As described above, the control device 200 calculates the restart time of the detecting device 300 corresponding to the received alive signal (S202 in FIG. 8). According to this calculation, the time frame of each detecting device 300 is fixed, so a single restart time is determined regardless of the timing at which the control device 200 received the alive signal. Therefore, compared to a case where the time frame differs depending on the timing at which the control device 200 received the alive signal, it is possible to reduce the possibility that scheduled communications of multiple detecting devices 300 will overlap with each other.

[0069] With reference to FIG. 10 , a scenario will be described in which communication timings do not overlap among multiple detection devices 300 and there is no influence of radio wave shielding or the like. FIG. 10 illustrates communication timings in which slave device 1 with ID “1” transmits an alive signal at 15:00, slave device 3 with ID “3” transmits an alive signal at 15:20, and slave device 2 with ID “2” transmits an alive signal at 15:40. In this example, the scheduled communication times of slave devices 1 to 3 do not overlap with each other, and there is no influence of radio wave shielding by metal or the like, and the alive signals transmitted by slave devices 1 to 3 are received by the control device 200. Note that, since the allocation shown in FIG. 9 cycles between slave devices 1 to 3 from 0:00 to 1:00, in FIG. 10 as well, the time slot for scheduled communication cycles between slave devices 1 to 3 from 15:00 to 16:00. The same applies before 15:00 and after 16:00.

[0070] FIG. 11 shows a scenario in which the first transmission from the slave unit 3 is not received by the master unit, but the second transmission is received. Reasons why the slave unit or master unit cannot receive a signal include, but are not limited to, the following: The strength of the radio waves emitted by the detection device 300 was below the level at which the control device 200 could properly receive them. A metal support or a vehicle body between the detection device 300 and the control device 200 blocked the radio waves, preventing them from being properly received by the control device 200. The timing of scheduled communications by multiple detection devices 300 overlapped, preventing some or all of the overlapping communications from being properly received by the control device 200. The presence of a device that emits radio waves other than those included in the parking device 100 prevented the control device 200 from properly receiving the survival signal emitted by the detection device 300 due to the influence of the radio waves emitted by that device. The strength of the radio waves emitted by the control device 200 was below the level at which the detection device 300, which emitted the survival signal, could properly receive it. Because there was a metal support and the body of the vehicle between the detection device 300 and the control device 200, the radio waves were blocked and could not be received properly by the detection device 300. The detection device 300 that sent out the alive signal broke down before it was able to receive the response signal.

[0071] As such, for some reason, there may be cases where a slave or master cannot receive a signal intended for itself. However, as shown in Figure 11, even if a slave (e.g., slave 3) repeatedly transmits a survival signal, collisions will not occur between scheduled communications if the time slots assigned to each of slaves 1 to 3 do not overlap and the number of transmissions of survival signals is sufficiently small. Therefore, by lengthening the time slots assigned to each of slaves 1 to 3, the possibility of collisions between scheduled communications can be reduced.

[0072] 6. Comparison with randomly starting scheduled communication The above explanation is for the case where time slots are assigned to each detection device 300 so that scheduled communications do not overlap (see FIG. 9). In contrast, the detection device 300 of the parking device according to the comparative example starts scheduled communications randomly.

[0073] FIG. 12 shows a scenario in which handset 1 to handset 3 randomly start scheduled communications, resulting in the start time of handset 2 and handset 3 being the same. Handset 1's scheduled communications do not collide with handset 2 or handset 3's scheduled communications, so the first survival signal is received by the parent unit, and the response signal transmitted from the parent unit is received by handset 1. However, handset 2 and handset 3 simultaneously start transmitting survival signals to the parent unit, so the survival signals transmitted by handset 2 and handset 3 may collide with each other and not be received by the parent unit. In the illustrated example, the survival signals from handset 2 and handset 3 are both received by the parent unit, and a response signal is transmitted from the parent unit. However, the repeated transmission of survival signals results in the effective communication status of handset 2 and handset 3 remaining valid for a longer period than shown in FIG. 11. When the communication state is valid, the power consumption of the detection device 300 increases. Therefore, if the alive signal is repeatedly transmitted, the power consumption of the detection device 300 increases compared to when the alive signal is not repeatedly transmitted, and the remaining battery power of the battery 320 may decrease significantly.

[0074] 9 to 11, by setting the start times of scheduled communication so that they do not overlap among multiple detection devices 300, it is possible to reduce the possibility of collisions between transmissions of survival signals among two or more detection devices 300. Therefore, the parking device 100 can keep power consumption low.

[0075] The scheduled communication described above is initiated mainly when the restart time designated by the control device 200 (see FIG. 4) arrives. However, scheduled communication may also be initiated when the detection unit 312 (see FIG. 4) detects the movement of the pallet 104 (see FIG. 4) (S102 in FIG. 5; Yes).

[0076] Second Embodiment The parking device 100 according to the first embodiment repeats transmitting a survival signal until the detection device 300 receives a response signal (see FIGS. 4 and 5). In contrast, the parking device 100A according to the present embodiment stops transmitting the survival signal when the number of times the response signal cannot be received reaches a certain number. Below, explanations of the parts that are the same as the parking device 100 will be omitted, and the explanation will focus on the parts that are different from the parking device 100.

[0077] 7. Limiting the number of outgoing calls The detection device 300A of the parking device 100A shown in Fig. 13 includes a transmission counter 324 that stores the number of transmissions. The control unit 316 of the detection device 300A limits the number of transmissions of scheduled communications based on the number of transmissions counted by the transmission counter 324. The transmission counter 324 is, for example, a storage unit that can write and read the number of survival signals transmitted by the communication unit 318, but is not limited to this. The transmission counter 324 may be, for example, a circuit that counts the number of survival signals transmitted by the communication unit 318, and may be a dedicated circuit that has a reset input that initializes the counted number of transmissions to 0.

[0078] 14 is a flowchart showing the processing flow by the detection device 300A. The maximum number of attempts represented by the symbol n is 2, and the value of the transmission counter is represented by the symbol i. Note that the determination of whether the restart time has arrived (S301) is the same as S101 of the parking device 100 (see FIG. 5).

[0079] When it is determined that the restart time has arrived (S301; Yes), the control unit 316 sets the transmission counter 324 to an initial value of "0" (S302). Subsequently, the detecting device 300A transmits an alive signal (S303).

[0080] As illustrated in FIG. 15, the survival signal is a signal having a data structure including the ID of each detection device 300A and the accelerations in the x, y, and z directions of the pallet 104 to which each detection device 300 is attached. For example, when the pallet 104 to which the detection device 300 with an ID of 1 is attached is not accelerating in any direction, the survival signal is a signal having a data structure in which the ID is "1" and the accelerations x, y, and z are all "0".

[0081] Returning to FIG. 14, after finishing transmitting the survival signal, the control unit 316 increments the value i of the transmission counter 324 by 1 (S304).

[0082] After waiting for a predetermined time (S305), the control unit 316 determines whether the communication unit 318 has received a response signal for the own device (S306). When it is determined that the response signal has been received (S306; Yes), the transmission of the survival signal is stopped (S307), and the control flow returns to the beginning, and the processing after S301 is continued.

[0083] Also, even when the control unit 316 determines that the communication unit 318 has not received a response signal for the own device (S306; No), the transmission of the survival signal may be stopped as follows (S309). First, when the control unit 316 determines that it has not received a response signal for the own device (S306; No), subsequently, it determines whether the number of attempts i is less than the maximum number of attempts n (S308). Note that the maximum number of attempts n is stored in the storage unit 314, for example, in a rewritable manner. In this pattern, since n is 2, the control unit 316 determines that the current number of attempts i is less than the maximum number of attempts n (S308; Yes). The control unit 316 returns the control flow to S303, transmits the survival signal again (S303), and increments the number of attempts i by 1 to 2 (S304).

[0084] After waiting for a predetermined time (S305), when it is determined that a response signal has not been received for the second survival signal (S306; No), the control unit 316 determines that i < n is not satisfied (S308; No), and stops the transmission of the survival signal (S309).

[0085] If the control unit 316 determines that the number of attempts i is not less than the maximum number of attempts n (S308; No) and stops transmitting the alive signal (S309), it waits for a predetermined time (S310) and determines whether the pallet 104 has moved (S311).

[0086] If it is not determined that the pallet 104 has moved (S311; No) even after waiting for a predetermined time (S310), the control unit 316 repeats waiting for a predetermined time (S310).

[0087] The determination of whether the pallet 104 has moved (S311) is made, for example, based on whether the magnitude of the acceleration detected by the detection unit 312 exceeds a predetermined threshold. That is, the control unit 316 determines that the pallet 104 has moved if the magnitude of the acceleration detected by the detection unit 312 exceeds the predetermined threshold (S311; Yes). The control unit 316 does not determine that the pallet 104 has moved if the magnitude of the acceleration detected by the detection unit 312 is equal to or less than the predetermined threshold (S311; No).

[0088] The criteria for determining whether the pallet 104 has moved are not limited to those described above. For example, the control unit 316 may determine that the pallet 104 has moved if the magnitude of any one of the acceleration in the x direction, the acceleration in the y direction, and the acceleration in the z direction exceeds a predetermined threshold. The threshold may be different for the x direction, the y direction, and the z direction, or may be the same for all directions.

[0089] In addition to or instead of determining whether the pallet 104 has moved (S311), the control unit 316 may perform other processing, such as determining whether an impact has been applied to the pallet 104.

[0090] If it is determined that the pallet 104 has been moved (S311; Yes), the control unit 316 returns the flow of control to S302 and continues the processing from S302 onwards.

[0091] If it is not determined that the pallet 104 has been moved (S311; No), the control unit 316 determines whether the restart time has arrived (S312). If it is determined that the restart time has arrived (S312; Yes), the control unit 316 returns the flow of control to S302 and continues the processing from S302 onwards. If it is not determined that the restart time has arrived (S312; No), the control unit 316 returns the flow of control to S310 and repeats the processing from S310 onwards.

[0092] In this manner, in this embodiment, a maximum number of attempts n is set, so that if the detection device 300A does not receive a response signal, the number of times it repeats transmitting a survival signal, waiting for a predetermined time, and determining whether a response signal has been received is limited.

[0093] In this embodiment, there are two control paths leading to the control to stop transmitting the alive signal (S307, S309): when a response signal addressed to the device itself is received (S306; Yes) and when the number of attempts i is not less than the maximum number of attempts n (S308; No). By providing a control path to stop transmitting the alive signal when the number of attempts i is not less than the maximum number of attempts n (S308; No), it is possible to delay transmitting the alive signal (S303) until movement of the pallet 104 is detected (S311; Yes) or until the resumption time arrives (S312; Yes). This makes it possible to avoid exhausting the remaining battery power of the battery 320 (see FIG. 13) by attempting to repeat scheduled communication even when it is difficult to receive a response signal due to poor radio wave conditions or other reasons.

[0094] 16 shows a comparative example in which the maximum number of attempts n is not set, for example, a case in which scheduled communication is repeated in the parking device 100 according to the first embodiment. Because the survival signal transmitted by the slave unit 3 is not received by the master unit and the slave unit 3 does not receive a response signal, the slave unit 3 continues to transmit the survival signal even after the slave unit 2 starts scheduled communication and begins transmitting the survival signal. As a result, in the parking device 100, the survival signals transmitted by the slave units 2 and 3 overlap, making it difficult for the master unit to receive the survival signals transmitted by both the slave units 2 and 3.

[0095] In contrast, Figure 17 shows an example of scheduled communication by the parking device 100A in which the maximum number of attempts n is set to 2. The slave 3 does not transmit a survival signal more than n times. This reduces the consumption of the battery 320 (see Figure 13) due to transmission of the survival signal, etc., compared to when the maximum number of attempts is not set (see Figure 16). It also prevents the survival signals transmitted by multiple detection devices 300 from overlapping and colliding with each other, resulting in the control device 200 not receiving the signals.

[0096] Note that when the control unit 316 (see FIG. 13) determines that the pallet 104 has moved (S311 in FIG. 14; Yes), the possibility of an abnormality occurring in the pallet 104 increases compared to when the state of the pallet 104 remains unchanged. Therefore, even if the restart time has not arrived, the detection device 300 transmits a survival signal while the pallet 104 is moving, allowing the control device 200 to acquire the state of the pallet 104 (acceleration, inclination, etc.) at a time closer to the restart time. Therefore, according to this embodiment, a highly reliable parking device 100A (see FIG. 13) can be provided.

[0097] 8. Setting the time In the parking devices 100 and 100A described above, the time counter 218 and the time counter 322 synchronize the timing of communication between the control device 200 and each detection device 300. That is, the restart count specified by the control device 200 is measured by the time counter 218 of the control device 200, and the count at which the detection device 300 resumes scheduled communication is measured by the time counter 322 of each detection device 300. Because the characteristics of integrated circuits (ICs) vary from device to device, the count intervals of the time counters 218 and 322 may differ between the control device 200 and the detection device 300, or between multiple detection devices 300. If a detection device 300 resumes scheduled communication based on counts with different intervals, scheduled communication with other detection devices 300 may overlap, potentially reducing the reliability of the scheduled communication.

[0098] To avoid such a decrease in reliability, the count specifying the restart time may be corrected as shown in Fig. 18. For example, when the detection device 300 receives a response signal from the control device 200 in response to the survival signal transmitted by the detection device 300, the detection device 300 may subsequently transmit a correction signal.

[0099] The control device 200 may perform learning by calculating the difference between the count indicated by the timing counter 322 at the time when the control device 200 transmits a response signal and the count indicated by the timing counter 322 at the time when the control device 200 receives a correction signal, and storing the difference in the storage unit 212. When transmitting a response signal next time, the control device 200 may perform correction by calculating the learned difference with respect to a designated restart count.

[0100] The detection device 300 may transmit a correction signal every time it receives a response signal to a survival signal, or may transmit the correction signal once every few times, or may transmit the correction signal when certain conditions are met.

[0101] This correction allows the time to be synchronized between the control device 200 and each of the detecting devices 300 even if the time counters 218 and 322 count differently. This reduces the possibility of scheduled communication collisions between multiple detecting devices 300.

[0102] <Variation 1> In the parking device 100A according to the second embodiment, the maximum number of attempts n for the survival signal of the detection device 300 is constant. In contrast, in the first modification, control is performed to change the maximum number of attempts n according to the remaining battery charge. Below, explanations of the parts that are similar to the parking devices 100 and 100A will be omitted, and the explanation will focus on the parts that are different from the parking devices 100 and 100A.

[0103] 9. Maximum number of attempts n controlled according to remaining battery power 19, the detection device 300B of the parking device 100B includes a battery remaining capacity measurement unit 326 that measures the remaining capacity of the battery 320. The battery remaining capacity measurement unit 326 is, for example, a voltmeter that can measure the potential difference between the terminals of the battery 320, but is not limited to this. The flow of control by the control unit 316 of the detection device 300B is shown below.

[0104] 20 shows the flow of control by the control unit 316. Steps S401 to S407 and steps S410 to S414 are respectively similar to steps S301 to S307 and steps S308 to S312 (see FIG. 14) of the control by the control unit 316 (see FIG. 13) of the parking device 100A.

[0105] 19 and 20, when control unit 316 of detection device 300B does not determine that a response signal addressed to itself has been received (S406; No), it compares the remaining battery charge with a threshold (S408). Specifically, control unit 316 compares the remaining charge of battery 320 measured by remaining battery charge measurement unit 326 with a predetermined threshold, and when it determines that the remaining battery charge is below the threshold (S408; Yes), it sets maximum number of attempts n to half (n / 2) (S409). When control unit 316 does not determine that the remaining battery charge is below the threshold (S408; No), it does not change maximum number of attempts n and continues subsequent processing (S410 and thereafter).

[0106] The more the survival signal is transmitted, the lower the remaining charge of the battery 320 becomes. Therefore, if the survival signal continues to be transmitted while the remaining charge of the battery 320 is low, the detection device 300B may stop operating. In contrast, according to the parking device 100B of Modification 1, the number of survival signals transmitted is reduced by reducing the maximum number of attempts n, thereby slowing the rate at which the remaining charge of the battery 320 decreases. This enables efficient scheduled communication. Note that the content of the process (S409) for changing the maximum number of attempts n may be changed as appropriate. For example, the control unit 316 may divide the remaining battery charge of the battery 320 into m stages and execute control to change the maximum number of attempts n at each stage of the remaining battery charge.

[0107] <Variation 2> In the parking devices 100 and 100A according to the above-described embodiments and the parking device 100B according to the first modification, the detection devices 300, 300A, and 300B transmit a survival signal, and the control device 200 transmits a response signal in response to a control signal. In contrast, in the parking device 100C according to the second modification, the control device takes the lead in transmitting a signal to inquire about the survival of each detection device. The following description will focus on the differences from the parking devices 100, 100A, and 100B.

[0108] 21, the parking device 100C includes a control device 200C and a detection device 300C. In the parking device 100C, the control device 200C, not the detection device 300C, includes the transmission counter 220. The transmission counter 220 is a counter that stores the number of transmissions made by the control device 200C.

[0109] 10. Scheduled communication initiated by the parent unit 22 is a flowchart showing the flow of processing by the control device 200C. As in the example of the second embodiment described with reference to FIG.

[0110] In the parking device 100C, the control unit 214 of the control device 200 also calculates the resumption time of the scheduled communication of the detection device 300C (S601, see S202 in FIG. 8). However, unlike the parking device 100, from the determination of the arrival of the resumption time described below, processing is performed by the control unit 214 of the control device 200, not the detection device 300.

[0111] The control unit 214 determines whether the restart time has arrived (S602). If the control unit 214 determines that the restart time has arrived (S602; Yes), it sets the initial value "0" in the transmission counter 220 (S603).

[0112] Next, the control unit 214 causes the communication unit 216 to transmit an alive-state confirmation signal (S604). The alive-state confirmation signal is transmitted from the control device 200C to the detection device 300C, and has a data structure similar to that of the alive-state signal shown in FIG. 6, for example.

[0113] When the communication unit 216 finishes transmitting the first survival confirmation signal, the control unit 214 increases the value i stored in the transmission counter 220 by 1 (S605).

[0114] After waiting for a predetermined time (S606), the control unit 214 determines whether the communication unit 216 has received a response signal for the own device (S607). When the control unit 214 determines that the communication unit 216 has not received the response signal (S607; No), next, it determines whether the number of attempts i is less than the maximum number of attempts n (S608). Since the maximum number of attempts n is 2, the control unit 214 determines that the current number of attempts i is less than the maximum number of attempts n (S608; Yes). The control unit 214 returns to S604 and repeats the transmission of the survival confirmation signal (S604), increasing the number of attempts i by 1 to 2 (S605).

[0115] After waiting for a predetermined time again (S606), when the communication unit 216 does not receive a response signal for the second survival confirmation signal either (S607; No), the control unit 214 determines that i < n is not satisfied (S608; No). The control unit 214 determines that the detection device 300C has failed (S609), stops transmitting the survival confirmation signal (S610), returns the control flow to the beginning, and continues the process from S601.

[0116] Referring to FIGS. 21 and 23, the processing flow by the detection device 300C will be described. First, the control unit 316 determines whether the communication unit 318 has received a survival confirmation signal (S701). When it is determined that the survival confirmation signal has not been received (S701; No), the control unit 316 repeats the determination of the reception of the survival confirmation signal.

[0117] When the control unit 316 determines that the communication unit 318 has transmitted the survival confirmation signal (S701; Yes), the control unit 316 causes the communication unit 318 to transmit a response signal (S702). After transmitting the response signal (S702), the control unit 316 returns the control flow to the beginning and continues the process from S701.

[0118] According to the parking device 100C, the control device 200C starts scheduled communication, and the number of attempts is controlled by the control device 200. Therefore, compared to when each of the detection devices 300 starts scheduled communication, the possibility of scheduled communication collisions can be reduced.

[0119] In the parking devices 100, 100A, 100B, and 100C, the detection devices 300, 300A, 300B, and 300C communicate directly with the control devices 200 and 200C, but they may communicate via a repeater.

[0120] Based on the configurations shown in each embodiment of the present disclosure, those skilled in the art may add, delete, or modify components as appropriate, or may add, omit, or modify processes as appropriate, as long as they comply with the gist of the present disclosure.

[0121] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0122] 100, 100A, 100B, 100C...Parking equipment 102…post 103...Beam 104...Palette 105...Car stop 106...Elevator 107...Pallet drive device 200, 200C...Control device 208...Operation panel 212...Storage section 214...Control unit 216…Communications Department 218...Time counter 300, 300A, 300B, 300C...Detection device 312...Detection unit 314...Storage section 316...Control unit 318…Communications Department 320...Battery 322...Time counter 324...Call counter 326...Battery level measurement unit

Claims

1. A plurality of detection devices are installed on a plurality of pallets on which vehicles can be placed, and a control device that communicates with each of the detection devices, the detection device starts repeatedly transmitting a live signal to the control device in accordance with a transmission start condition; the control device transmits a response signal specifying a restart time at which the detection device corresponding to the received alive signal will start to repeat transmitting the alive signal; the detection device stops repeating the transmission of the alive signal in accordance with a transmission stop condition; the transmission start condition includes the arrival of either a restart time previously determined for each of the detecting devices or a restart time designated by the response signal received by the detecting device for itself; The transmission stop condition includes that the detection device receives a response signal to the parking device.

2. the control device specifies different restart times for the plurality of detection devices; The parking device according to claim 1.

3. the control device assigns to each of the detection devices a start time point of one or more periods obtained by dividing a unit period by a number equal to or greater than the total number of the plurality of detection devices, and specifies the mutually different restart times.

3. The parking device according to claim 2.

4. the transmission stop condition includes that the response signal received by the detection device is a response signal addressed to the detection device itself, or that the number of transmissions of the survival signal has reached a predetermined upper limit value. The parking device according to claim 3.

5. the unit period is equal to or greater than the total time required for the detection devices to repeatedly transmit the alive signal until the alive signal reaches the predetermined upper limit value and to wait for the response signal from the control device, for all of the detection devices.

5. The parking device according to claim 4.

6. the detection device includes a battery that supplies power to the detection device, and the upper limit value of the detection device is reduced according to the remaining charge of the battery.

6. The parking device according to claim 5.

7. repeating the transmission includes transmitting a second transmission when the response signal for the device itself is not received from the control device after completing a first transmission, and a communication power of the second transmission being greater than a communication power of the first transmission; The parking device according to claim 1.

8. the transmission start condition includes a condition related to the movement of the pallet to which the detection device is attached being satisfied; The parking device according to claim 1.

9. The condition regarding the movement of the pallet includes that the magnitude of the acceleration of the pallet exceeds a predetermined threshold.

9. The parking device according to claim 8.

10. The magnitude of the acceleration of the pallet is measured separately in the vertical and horizontal directions; The threshold value of the magnitude of the acceleration of the pallet in the vertical direction is smaller than the threshold value of the magnitude of the acceleration of the pallet in the horizontal direction.

10. The parking device according to claim 9.

11. the vitality signal includes information that can identify each of the detection devices; The parking device according to claim 1.

12. A plurality of detection devices are installed on a plurality of pallets on which vehicles can be placed, and a control device that communicates with each of the detection devices, the control device starts repeatedly transmitting a survival confirmation signal to one of the detection devices in accordance with a transmission start condition; the detection device transmits a response signal when receiving the survival confirmation signal for itself; the control device stops repeatedly transmitting the existence confirmation signal to one of the detection devices in accordance with a transmission stop condition; the transmission start condition includes satisfying that a restart time predetermined for each of the detection devices has arrived; A parking device, wherein the transmission stop condition includes receiving the response signal from the detection device that transmitted the survival confirmation signal.

Images