A dynamic monitoring unattended sales system

Abstract

The application discloses a kind of dynamic monitoring unattended sales system, it is related to the technical field of electromagnetic locking control of unattended sales place, for solving the problem that the adjustment is inaccurate due to the participation of transient locking state in excitation current adjustment in the repeated recovery locking process of electromagnetic lock;The system maintains locking through the first excitation current, switches to the second excitation current to recover locking when detecting separation, and judges whether to enter the corresponding steady state after switching back to the first excitation current;The locking state before steady state formation is not used as the basis for reducing the first excitation current, and separation again is still used to maintain or improve the first excitation current;From this, the accuracy of excitation current self-adaptive adjustment and locking reliability are improved.

Description

Technical Field

[0001] This application relates to the field of electromagnetic interlocking control technology for unattended sales locations, and in particular to a dynamic monitoring unattended sales system. Background Technology

[0002] Unattended sales outlets typically use controllers to automatically control electromagnetic locks installed at entrances and exits, product cabinets, storage lockers, equipment compartments, or equipment boxes. To reduce energy consumption when the locked components are in a prolonged locked state, the electromagnetic locks can maintain the lock with a small excitation current when the locked components are in the locked state. When the controller detects that the electromagnetic lock has disengaged, the controller increases the excitation current of the electromagnetic lock to restore the electromagnetic lock to the locked state. After confirming that the electromagnetic lock has been restored to the locked state, the controller reduces the excitation current again to continue maintaining the lock on the locked components.

[0003] Existing low-power electromagnetic lock control methods can adjust the excitation current used to maintain the locked state based on the separation of the electromagnetic lock under a small excitation current. Under continuous external influence, the electromagnetic lock may repeatedly undergo the control process of maintaining the lock with a small excitation current, causing separation, increasing the excitation current to restore the lock, and then reducing the excitation current again.

[0004] However, the controller reducing the excitation current back to the level used to maintain the lockout does not automatically indicate that the electromagnetic lock has reached a stable operating state corresponding to that current level. Before the transient effects of the previous larger excitation current control have subsided, the subsequent brief lockout state of the electromagnetic lock may still be affected by the previous larger excitation current control. Therefore, this brief lockout state is insufficient to independently prove that the current smaller excitation current has the corresponding lockout holding capability. Especially when the continuous external action has not disappeared, the same continuous external action may cause the electromagnetic lock to continuously execute the control process of increasing the excitation current multiple times to restore the lockout. If the controller reduces the excitation current to the level used to maintain the lockout, the electromagnetic lock will not necessarily achieve a stable operating state corresponding to that current level. If the brief lockout state after the initial lockout, before a stable operating state corresponding to the smaller excitation current is established, participates in excitation current adjustment in the same way as the lockout state after a stable operating state has been established, then the transient effect formed by the previous larger excitation current control may be mistakenly taken as a positive basis for the current smaller excitation current having a further reduction margin. As a result, the controller continues to reduce the excitation current before obtaining effective stable holding data that can independently reflect the lockout holding capability of the current smaller excitation current, affecting the accuracy of the excitation current adaptive adjustment. Therefore, it is necessary to distinguish the evaluation qualifications of different detection results in the same recovery process in excitation current adjustment. Summary of the Invention

[0005] This application provides a dynamic monitoring unattended sales system, used to distinguish the locking state used to adjust the first excitation current when different excitation currents are used for locking and recovery control of the electromagnetic lock, thereby reducing the impact of the previous second excitation current control on the adjustment of the first excitation current. The technical solution is as follows: On one hand, a dynamic monitoring unattended sales system is provided, including an electromagnetic lock and a controller. The controller is used to acquire a separation detection signal of the electromagnetic lock while the electromagnetic lock is maintained in a locked state with a first excitation current. In response to the separation detection signal, the controller switches the electromagnetic lock to a second excitation current to restore the locked state, and switches back to the first excitation current after restoring the locked state, wherein the second excitation current is greater than the first excitation current. After each switch to the first excitation current, the controller determines whether the electromagnetic lock has entered a steady state corresponding to the first excitation current. If the separation detection signal is acquired again before entering the steady state, the controller prohibits reducing the first excitation current based on the locked state between the current switch to the first excitation current and the acquisition of the separation detection signal again. The controller adjusts the first excitation current according to the formation of the steady state and the acquisition of the separation detection signal.

[0006] In one possible implementation, the electromagnetic lock is a locking device that achieves locking through magnetic attraction between an electromagnet and a attracting element; depending on the locked component and the installation position, the electromagnetic lock may include at least one of the following: an electromagnetic door lock for an entrance door, an electromagnetic cabinet lock for a shopping cabinet or storage cabinet that uses magnetic attraction between an electromagnet and a attracting element, and an electromagnetic lock for an equipment compartment door, maintenance door, or equipment box door.

[0007] In one possible implementation, the controller obtains the actual excitation current of the electromagnetic lock after it switches from the second excitation current to the first excitation current, and determines whether the actual excitation current enters the current range corresponding to the first excitation current; after the actual excitation current enters the current range, it determines that the current transition of the electromagnetic lock from the second excitation current to the first excitation current has ended.

[0008] In one possible implementation, after determining that the current transition has ended, magnetic state detection data for characterizing the magnetic holding state of the electromagnetic lock is acquired; based on the change of the magnetic state detection data after the current transition has ended, it is determined whether the electromagnetic lock has disengaged from the magnetic state corresponding to the previous second excitation current; after determining that the electromagnetic lock has disengaged from the magnetic state corresponding to the previous second excitation current, it is determined that the electromagnetic lock has entered a steady state corresponding to the first excitation current.

[0009] In one possible implementation, the electromagnetic lock includes an electromagnet, a magnetic attraction component that cooperates with the electromagnet, and a magnetic state detector; the magnetic attraction component is a part that can form a magnetic attraction with the electromagnet under the magnetic force generated by the electromagnet; the magnetic state detector is used to obtain magnetic state detection data between the electromagnet and the magnetic attraction component; the controller determines whether the magnetic state corresponding to the previous second excitation current has ended based on the changes in the continuously obtained magnetic state detection data.

[0010] In one possible implementation, if the separation detection signal is acquired again before the electromagnetic lock enters the steady state, the controller switches the electromagnetic lock to the second excitation current again to restore the locked state; it prohibits reducing the first excitation current based on the locked state formed after the previous switch to the first excitation current, and uses the acquired separation detection signal again as the basis for maintaining or increasing the first excitation current.

[0011] In one possible implementation, when no steady state corresponding to the first excitation current is formed between two consecutive switching of the electromagnetic lock to the second excitation current, the controller determines the two consecutive second excitation current controls and the first excitation current control between them as the same continuous recovery process.

[0012] In one possible implementation, the controller determines the number of times the electromagnetic lock is switched to the second excitation current during the continuous recovery process; after the continuous recovery process ends, it determines the steady-state holding status of the electromagnetic lock under the first excitation current; and it determines the adjustment direction of the first excitation current based on the number of recovery times and the steady-state holding status.

[0013] In one possible implementation, the controller determines the effective evaluation duration of the first excitation current; wherein only the time during which the electromagnetic lock is maintained in a locked state by the first excitation current after entering a steady state corresponding to the first excitation current is included in the effective evaluation duration; the time corresponding to the second excitation current and the time after switching from the second excitation current to the first excitation current and before entering the steady state are not included in the effective evaluation duration.

[0014] In one possible implementation, if, within a preset statistical period, the electromagnetic lock generates the separation detection signal again before entering the steady state each time it switches from the second excitation current to the first excitation current, causing the effective evaluation time to not reach the preset evaluation time, then the controller prohibits reducing the first excitation current.

[0015] On the other hand, an electromagnetic lock control device is provided, including a signal acquisition module, a recovery control module, a steady-state judgment module, an evaluation module, and a current adjustment module. The signal acquisition module is used to acquire a separation detection signal of the electromagnetic lock while the electromagnetic lock is maintained in a locked state with a first excitation current. The recovery control module is used to switch the electromagnetic lock to a second excitation current to restore the locked state in response to the separation detection signal, and switch back to the first excitation current after restoring the locked state, wherein the second excitation current is greater than the first excitation current. The steady-state judgment module is used to determine whether the electromagnetic lock has entered a steady state corresponding to the first excitation current after each switch to the first excitation current. The evaluation module is used to prohibit the reduction of the first excitation current based on the locked state between the current switch to the first excitation current and the re-acquisition of the separation detection signal when the separation detection signal is acquired again before entering the steady state. The current adjustment module is used to adjust the first excitation current according to the formation of the steady state and the acquisition of the separation detection signal.

[0016] The dynamic monitoring unattended sales system provided in this application embodiment, after the electromagnetic lock recovers from the second excitation current and switches back to the first excitation current, does not directly use the subsequently formed lockout state as the basis for the first excitation current to maintain the lockout. Instead, it further determines whether the electromagnetic lock has entered a steady state corresponding to the first excitation current. When a separation detection signal is generated again before the steady state is formed, the first excitation current is not reduced based on the lockout state. As a result, the adjustment basis of the first excitation current can correspond to the stable lockout state actually formed by the electromagnetic lock under the first excitation current, reducing the impact of the brief lockout state formed by repeated execution of the second excitation current control under continuous external action on the adjustment of the first excitation current.

[0017] Meanwhile, the separation detection signal generated again during the period before a steady state is formed still retains its evaluation function for maintaining or increasing the first excitation current. This ensures that the detection data during the recovery process is not uniformly deleted, but participates in the adjustment of the first excitation current according to the actual blocking state it can represent. This reduces the adjustment deviation caused by the transient blocking state being mistakenly used as the basis for reduction.

[0018] Furthermore, after the first excitation current is adjusted, this embodiment of the application re-forms the corresponding steady-state evaluation and effective evaluation duration for the adjusted first excitation current, without directly inheriting the positive evaluation data corresponding to the first excitation current before adjustment; when the first excitation current control stage is interrupted by the new second excitation current recovery process, the control time before the steady state is formed is not merged with the subsequent control stage to form an effective evaluation duration; thus, the positive evaluation data supporting the reduction of the first excitation current is bound to the current actual first excitation current and its corresponding physical steady state, while the newly generated separation detection signal is still retained as the negative evaluation basis for maintaining or increasing the first excitation current. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the implementation environment of a dynamic monitoring unattended sales system provided in an embodiment of this application; Figure 2 This is a schematic diagram of an electromagnetic lock control process provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electromagnetic lock provided in an embodiment of this application; the electromagnetic lock may include an electromagnet, a magnetic attraction component that cooperates with the electromagnet, and a magnetic state detector; the magnetic attraction component is a part that can form a magnetic attraction with the electromagnet under the magnetic force generated by the electromagnet, such as the armature plate or suction plate in an entrance electromagnetic door lock, the magnetic suction plate in a cabinet door electromagnetic cabinet lock, or other locking parts that can form a magnetic attraction with the electromagnet; the magnetic state detector is used to obtain magnetic state detection data between the electromagnet and the magnetic attraction component.

[0020] Figure 4 This is a schematic diagram of a continuous recovery process provided in an embodiment of this application; Figure 5 This is a schematic diagram illustrating an effective method for determining evaluation duration provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of an electromagnetic lock control device provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be further described below in conjunction with the embodiments; it should be understood that the described embodiments are only some embodiments of this application, and not all embodiments.

[0022] Example 1: Lockout control of a dynamic monitoring unattended sales system; Figure 1 This is a schematic diagram of the implementation environment of a dynamic monitoring unattended sales system provided in this application embodiment; the system includes a controller and an electromagnetic lock; the controller is connected to the electromagnetic lock and is used to obtain the status information of the electromagnetic lock and control the excitation current of the electromagnetic lock.

[0023] Optionally, the unattended sales venue can be an unattended convenience store, an unattended retail store, or other sales venue that requires automatic locking control of the locked components in the absence of personnel; the electromagnetic lock can be installed on the locked components such as the entrance and exit doors, merchandise cabinet doors, storage cabinet doors, equipment compartment doors, maintenance doors, or equipment box doors of the sales venue, and maintains the locked state when it is not necessary to release the locked components.

[0024] The electromagnetic lock referred to in this application is a locking device that uses an excitation coil to generate a magnetic attraction force in an electromagnet, and uses this magnetic attraction force to form a magnetic attraction between the electromagnet and a magnetically attracting component to achieve locking. Depending on the locked component and the installation location, the electromagnetic lock may include an electromagnetic door lock installed on an entrance or exit door, an electromagnetic cabinet lock for a shopping cabinet or storage cabinet that uses a magnetic attraction between an electromagnet and a magnetically attracting component, an electromagnetic lock installed on an equipment compartment door, maintenance door, or equipment box door, etc. The specific shape, installation location, and locked component of the above-mentioned electromagnetic locks may be different, but they can all change the magnetic attraction force by changing the excitation current. The electromagnetic locks described below in this application are not limited to the specific installation forms mentioned above.

[0025] The locked component can be a door, cabinet door, hatch, maintenance door, or equipment box door; the separation of the electromagnetic lock as referred to in this application means that the magnetic attraction between the electromagnet and the attracting component is released, or the gap or magnetic coupling between the two changes to the state detection component outputting a separation detection signal, and does not require the electromagnet and the attracting component to be completely disengaged.

[0026] In this embodiment, the first excitation current is the excitation current used to maintain the locking of the electromagnetic lock when the locked component is in the locked state; the second excitation current is the excitation current used to restore the electromagnetic lock to the locked state after the separation of the electromagnetic lock is detected, and the second excitation current is greater than the first excitation current; the first excitation current and the second excitation current are used to distinguish the excitation state used in different control stages, and are not limited to being fixed single current values.

[0027] Figure 2 This is a schematic diagram of an electromagnetic lock control process provided in an embodiment of this application; the controller controls the electromagnetic lock to maintain the locked state with a first excitation current, and acquires a separation detection signal of the electromagnetic lock during the process of maintaining the locked state; the separation detection signal is used to characterize the separation change of the current locked state of the electromagnetic lock, and can be generated by the state detection component of the electromagnetic lock or the detection circuit connected to the electromagnetic lock. The embodiments of this application do not limit the specific detector form that generates the separation detection signal.

[0028] In response to the separation detection signal, the controller switches the electromagnetic lock from the first excitation current to the second excitation current, so that the electromagnetic lock returns to the locked state; after determining that the electromagnetic lock has returned to the locked state, the controller switches the electromagnetic lock back from the second excitation current to the first excitation current.

[0029] In one possible implementation, after switching the electromagnetic lock to the second excitation current, the controller continues to acquire state detection data characterizing the locking state of the electromagnetic lock; when the state detection data indicates that the electromagnet and the attracting element have re-established a locking state, it is determined that the electromagnetic lock has resumed locking; optionally, to eliminate false judgments caused by instantaneous contact or detection fluctuations, it can be determined that the electromagnetic lock has resumed locking when the locking state is detected at consecutive preset number of sampling times; the state detection data can be obtained by the state detection component that generates the separation detection signal, or it can be obtained by the magnetic state detector.

[0030] It should be noted that when the controller switches the electromagnetic lock from the second excitation current to the first excitation current, it means that the control target of the electromagnetic lock has been switched back to the first excitation current. However, this control action itself does not mean that the electromagnetic lock has formed a stable working state corresponding to the first excitation current. Therefore, after each switch to the first excitation current, the controller further determines whether the electromagnetic lock has entered a steady state corresponding to the first excitation current.

[0031] In this embodiment, the steady state is used to characterize that the electromagnetic lock has broken free from the transient influence caused by the previous second excitation current control, and can be used to evaluate the locking status corresponding to the first excitation current; the controller can determine whether the current transition from the second excitation current to the first excitation current has ended based on the actual excitation current, and determine whether the electromagnetic lock has entered the steady state corresponding to the first excitation current based on magnetic state detection data or other state data that can characterize whether the transient influence corresponding to the previous second excitation current has ended.

[0032] If the electromagnetic lock generates a separation detection signal again before entering the steady state, it indicates that the lockout state formed after switching to the first excitation current has not lasted long enough to evaluate the first excitation current. Therefore, the controller prohibits reducing the first excitation current based on the lockout state between switching to the first excitation current and the generation of the separation detection signal again. The state information during this time period is not deleted, and the newly generated separation detection signal can still be used for lockout recovery and adjustment of the first excitation current.

[0033] It should be noted that the embodiments of this application do not uniformly determine the detection data obtained before entering the steady state as invalid data, but rather distinguish the way in which the detection results participate in the adjustment of the first excitation current based on the technical state that different detection results can prove. For the state of being locked before entering the steady state, since the locked state may still contain the influence of the previous second excitation current control, the locked state cannot independently prove that the current first excitation current has sufficient lock-up holding capability. However, the separation detection signal obtained again in the same stage indicates that the electromagnetic lock has separated again in the current control process. The separation detection signal does not depend on whether the aforementioned locked state can form a valid first excitation current evaluation sample, so it can still be used as a basis for maintaining or increasing the first excitation current.

[0034] Therefore, when processing the detection results obtained before entering the steady state in this embodiment, the limitation is to the evaluation use of the detection results in the first excitation current adjustment, rather than judging the detection results as measurement abnormalities or deleting the detection results; the lockout state and the separation detection signal can both be real state information, but because the technical facts they can prove are different, their evaluation qualifications are different: the lockout state during the period before the steady state is formed is insufficient to independently prove that the current first excitation current has a further reduction margin, while the separation detection signal generated again can directly characterize that the current lockout holding process has failed again; therefore, different detection results in the same transient stage are not classified as valid or invalid in a unified way, but are processed separately according to the direction of the first excitation current adjustment that they can support.

[0035] In one possible implementation, after the controller switches from the second excitation current to the first excitation current, it acquires the actual excitation current of the electromagnetic lock and compares the actual excitation current with the current range corresponding to the first excitation current; when the actual excitation current enters the current range, it determines that the current transition from the second excitation current to the first excitation current has ended.

[0036] The current range corresponding to the first excitation current can be determined based on at least one of the target value of the first excitation current, the excitation current drive error, the current detection accuracy, and the current fluctuation range during the stable operation of the first excitation current. The current range is set so that the actual excitation current corresponding to the normal drive error and the detection fluctuation is within the current range, while the actual excitation current that still deviates significantly from the level of the first excitation current during the change from the second excitation current to the first excitation current is outside the current range.

[0037] After the current transition is completed, the controller can continue to acquire magnetic state detection data to characterize the electromagnetic lock holding state; the magnetic state detection data may include at least one of magnetic field strength data, magnetic flux change data, magnetic coupling state data, or electrical response data that can reflect the change in the magnetic circuit state between the electromagnet and the attracting element.

[0038] In other possible implementations, the state data used to determine whether the transition has ended may also include inductance change data of the electromagnet coil, response data between the excitation voltage and the actual excitation current, or other data that can characterize the magnetic coupling state between the electromagnet and the attracting element as stabilizing. The above-mentioned different state data can be used alone or in combination with the actual excitation current or magnetic state detection data. The embodiments of this application determine whether the transient change caused by the previous second excitation current has ended through the above-mentioned state data, without limiting the use of a specific detector or a specific physical quantity.

[0039] In one executable steady-state determination method, after the actual excitation current enters the current range corresponding to the first excitation current, the controller continuously acquires magnetic state detection data at multiple sampling times and determines the amount of change in magnetic state detection data between adjacent sampling times or between adjacent sampling intervals; when the amount of change in the sampling times is not greater than the preset magnetic state change threshold, it is determined that the magnetic state change corresponding to the previous second excitation current has ended, and the electromagnetic lock has entered the steady state corresponding to the first excitation current.

[0040] The preset magnetic state change threshold can be determined based on the normal fluctuation range of the magnetic state detection data collected when the electromagnetic lock is running stably under the first excitation current; the preset quantity can be determined based on the detection sampling period and the short-term detection fluctuations that need to be excluded; thus, the steady state has at least one determination method that can be actually executed by the controller.

[0041] In this embodiment, the determination of steady state does not require the fixed waiting time after switching from the second excitation current to the first excitation current as the sole criterion. Since the coil parameters, magnetic circuit state, attracting component material, difference between the first and second excitation currents, and current operating state of different electromagnetic locks may differ, the actual current transition degree and magnetic state change degree corresponding to the same fixed waiting time may be different. Therefore, whether steady state has been formed can be determined based on the actual change results of the actual excitation current and magnetic state detection data, so that the starting point of the first excitation current evaluation corresponds to the moment when the current electromagnetic lock is actually freed from the influence of the previous second excitation current.

[0042] It should be noted that the aforementioned steady-state judgment is different from simply setting a fixed delay or debouncing time for the separation detection signal; the fixed delay or debouncing processing is mainly used to limit the confirmation time of the detection result, and cannot determine whether the transient effect of the previous second excitation current has ended, nor can it determine which first excitation current adjustment direction can be supported by the different confirmed detection results; the embodiments of this application further limit the conditions for the locking state to form a positive evaluation basis for reducing the first excitation current by judging whether the electromagnetic lock forms a steady state corresponding to the first excitation current; even if the locking state has been continuously detected before entering the steady state, the locking state is still not used to support the reduction of the first excitation current, while the separation detection signal generated again in the same stage can still be used to support the maintenance or increase of the first excitation current.

[0043] For example, the consecutive preset number can be three, five, or other numbers determined according to the sampling period; when five consecutive sampling times are used, if the change in magnetic state detection data between adjacent sampling times is not greater than the preset magnetic state change threshold, it can be considered that the magnetic state detection data has entered a stable fluctuation range; the preset magnetic state change threshold can be determined during the installation or debugging stage of the electromagnetic lock by keeping the electromagnetic lock continuously locked under the first excitation current and collecting multiple magnetic state detection data, based on the normal fluctuation range of the collected data; the specific sampling number and preset magnetic state change threshold in this embodiment can be set according to the electromagnetic lock model, sampling period, or detection accuracy.

[0044] Figure 3 This is a schematic diagram of the structure of an electromagnetic lock provided in an embodiment of this application; the electromagnetic lock may include an electromagnet, a magnetic attraction component that cooperates with the electromagnet, and a magnetic state detector; the magnetic attraction component is a component that can form a magnetic attraction with the electromagnet under the magnetic force generated by the electromagnet, such as an armature plate or a suction plate in the electromagnetic lock; the magnetic state detector is used to obtain magnetic state detection data between the electromagnet and the magnetic attraction component.

[0045] If a separation detection signal is acquired again before the electromagnetic lock enters the steady state, the controller will switch the electromagnetic lock to the second excitation current again to restore the locked state; it is prohibited to reduce the first excitation current based on the locked state formed after the previous switch to the first excitation current, and the newly acquired separation detection signal will be used as the basis for maintaining or increasing the first excitation current.

[0046] Regarding the adjustment of the first excitation current, in one possible implementation, when the steady state has been formed, the effective evaluation time has reached the preset evaluation time, and no separation detection signal has been generated during the corresponding evaluation process, the controller can reduce the first excitation current; when a separation detection signal is repeatedly generated before entering the steady state, the controller can maintain or increase the first excitation current; when the current evaluation data is insufficient to support increasing or decreasing the first excitation current, the controller maintains the current first excitation current.

[0047] In one possible implementation, after the controller adjusts the first excitation current based on the aforementioned evaluation results, the adjusted first excitation current is used as the new excitation current to be evaluated, and the corresponding steady state and effective evaluation time are re-determined for the adjusted first excitation current; the steady state holding time corresponding to the first excitation current before adjustment is not directly included in the effective evaluation time of the adjusted first excitation current.

[0048] Specifically, after the first excitation current is reduced or increased, the controller re-determines whether the electromagnetic lock has entered a steady state corresponding to the adjusted first excitation current while the electromagnetic lock is locked with the adjusted first excitation current. Only the time during which the locked state is maintained by the adjusted first excitation current after the formation of the steady state is included in the effective evaluation time corresponding to the adjusted first excitation current.

[0049] If a separation detection signal is obtained again before the steady state corresponding to the adjusted first excitation current is formed, the second excitation current is switched to restore the lockout in the manner described above, and the adjusted first excitation current is prohibited from being further reduced based on the lockout state during the period when the steady state has not yet been formed.

[0050] Therefore, each first excitation current value corresponds to an independent steady-state formation process and effective evaluation data, avoiding the direct use of the blocking and holding results obtained under a higher first excitation current as proof that a lower first excitation current has the same blocking and holding capability.

[0051] It should be noted that the steady-state judgment in this embodiment is not only used to determine the timing of the first excitation current adjustment, but also to determine whether the detection result can form an evaluation basis for a specific adjustment direction. For the adjustment of reducing the first excitation current, a steady state corresponding to the current first excitation current needs to be formed, and corresponding effective lock-in data needs to be obtained. For the adjustment of maintaining or increasing the first excitation current, the separation detection signal generated again can continue to be used as an evaluation basis when the positive evaluation conditions have not yet been formed. Therefore, the magnetic state detection is not only used to determine whether the electromagnetic lock is engaged or to determine when to restore low excitation control, but is used to determine whether the transient effect corresponding to the previous second excitation current has ended, thereby limiting the formation boundary of the positive evaluation data of the first excitation current.

[0052] Example 2: Evaluation of the continuous recovery process and the first excitation current; Figure 4 This is a schematic diagram of a continuous recovery process provided in an embodiment of this application; under the presence of continuous external forces, the electromagnetic lock may switch between the first excitation current and the second excitation current multiple times.

[0053] When no steady state corresponding to the first excitation current is formed between two consecutive switching of the electromagnetic lock to the second excitation current, the controller determines the two consecutive second excitation current controls and the first excitation current control between them as the same continuous recovery process; if this situation occurs continuously, multiple second excitation current controls and the first excitation current control between adjacent second excitation current controls can be classified into the same continuous recovery process.

[0054] In one possible implementation, when the electromagnetic lock switches from the second excitation current to the first excitation current and forms a steady state corresponding to the first excitation current, and no separation detection signal is generated again within a preset stabilization time, the current continuous recovery process is determined to be over; the preset stabilization time can be determined based on the time required for the electromagnetic lock to complete one stable holding evaluation under the first excitation current.

[0055] Conversely, if the electromagnetic lock generates a separation detection signal again before reaching the steady state after switching from the second excitation current to the first excitation current, then the current first excitation current control stage has not yet formed an independent first excitation current evaluation process; after switching back to the second excitation current, the aforementioned locking time before reaching the steady state is not combined with the subsequent first excitation current control stage to form an effective evaluation time; the subsequent first excitation current control stage needs to re-determine whether a steady state corresponding to the first excitation current has been formed.

[0056] The reason is that each switch back to the second excitation current will change the excitation state of the electromagnetic lock, giving new pre-transient conditions when switching back to the first excitation current. Therefore, the time elapsed before the first excitation current control stage reaches a steady state cannot indicate that the subsequent first excitation current control stage has completed the same level of steady-state transition. In other words, the reintroduction of the second excitation current interrupts the incomplete positive evaluation process of the first excitation current in the previous stage. The subsequent first excitation current control stage needs to re-establish a steady state corresponding to the first excitation current in order to regain the effective evaluation time for reducing the first excitation current.

[0057] For example, if a separation detection signal is generated again after a first time period following the first switch to the first excitation current, the controller then uses the second excitation current to restore the lockout; if a steady state is still not formed after a second time period following the second switch to the first excitation current, the first time period and the second time period are not considered as valid evaluation time because their sum reaches the preset evaluation time; only the time during which the steady state is formed after a switch to the first excitation current and the lockout is maintained is counted as valid evaluation time.

[0058] The controller can record the number of recovery cycles during the continuous recovery process, which is determined based on the number of times the electromagnetic lock is switched to the second excitation current during the continuous recovery process. After the continuous recovery process ends, the controller determines the steady-state holding status of the electromagnetic lock under the first excitation current and determines the adjustment direction of the first excitation current based on the number of recovery cycles and the steady-state holding status.

[0059] For example, when the number of recovery cycles during the continuous recovery process increases, and the system cannot achieve a stable state for the preset evaluation duration under the first excitation current after the continuous recovery process ends, the controller can maintain or increase the first excitation current. When the system achieves a steady state under the first excitation current after the continuous recovery process ends and continues to reach the preset evaluation duration without generating a separation detection signal, the controller can determine whether to reduce the first excitation current based on the corresponding evaluation results.

[0060] Figure 5 This is a schematic diagram of an effective evaluation duration determination method provided in an embodiment of this application; a control cycle that switches from the second excitation current to the first excitation current may include a recovery phase corresponding to the second excitation current, a transition phase from the second excitation current to the first excitation current, and a stable holding phase after entering the steady state corresponding to the first excitation current.

[0061] The controller only accumulates the time of the stable holding phase and determines the accumulated time as the effective evaluation duration of the first excitation current; the time corresponding to the second excitation current is used to restore the lockout state and is not maintained by the first excitation current, so it is not included in the effective evaluation duration of the first excitation current; the time after switching from the second excitation current to the first excitation current and before entering the steady state is also not included in the effective evaluation duration.

[0062] Therefore, the effective evaluation time in this application embodiment is different from the cumulative time of the controller being in the first excitation current control state within the preset statistical period; the time when the controller has output the first excitation current control, but the electromagnetic lock has not yet broken free from the transient influence corresponding to the previous second excitation current, is not used to prove that the first excitation current has a stable locking and holding capability; only after the electromagnetic lock forms a steady state corresponding to the first excitation current, the time of continuing to maintain the locking state with the first excitation current is included in the effective evaluation time.

[0063] For example, within a preset statistical period, even if the controller switches the electromagnetic lock from the second excitation current back to the first excitation current multiple times, as long as each first excitation current control generates a separation detection signal again before the steady state is formed, the corresponding multiple short first excitation current control stages will not form an effective evaluation duration for reducing the first excitation current, nor will the first excitation current be deemed to have obtained sufficient stable blocking evaluation by accumulating the duration of each short control stage.

[0064] The controller can set a preset statistical period for the first excitation current and accumulate the effective evaluation time of the first excitation current within the preset statistical period. The preset evaluation time is used to determine whether stable blocking data sufficient for adjusting the first excitation current has been formed under the current first excitation current. It can be determined based on the shortest duration required to complete the stable holding evaluation under the first excitation current.

[0065] In one possible implementation, during the installation or debugging phase of the electromagnetic lock, the electromagnetic lock is kept locked with a first excitation current. After confirming that a steady state corresponding to the first excitation current has been formed, the duration of multiple normal locking processes is recorded, and the preset evaluation duration is determined based on the recorded duration. For different models of electromagnetic locks or different first excitation currents, corresponding preset evaluation durations can be set separately.

[0066] If, within the preset statistical period, after each switch from the second excitation current to the first excitation current, a separation detection signal is generated again before entering the steady state, causing the effective evaluation time to fall short of the preset evaluation time, then the controller prohibits reducing the first excitation current; although the controller has repeatedly caused the electromagnetic lock to re-enter the first excitation current within the preset statistical period, it has not yet obtained sufficient evaluation data to prove that the first excitation current stably maintains the locked state.

[0067] The prohibition on reducing the first excitation current at this time does not mean that the first excitation current cannot maintain the lockout due to insufficient effective evaluation time, but rather that effective positive evaluation data that can prove the first excitation current has a further reduction margin has not yet been obtained. For the adjustment of reducing the first excitation current, this application embodiment requires the existence of steady-state lockout data that reaches the preset evaluation time as a positive evaluation basis. If the continuous recovery process repeatedly interrupts the formation of this positive evaluation basis, the first excitation current is not deduced to have a further reduction margin based on the brief lockout state.

[0068] In contrast, the separation detection signal obtained again during the period before the positive evaluation basis is formed can still characterize the re-separation, so the separation detection signal can still serve as a negative evaluation basis for maintaining or increasing the first excitation current.

[0069] For example, during a continuous external action, after the electromagnetic lock switches from the second excitation current to the first excitation current for the first time, a first separation detection signal is generated before a steady state corresponding to the first excitation current is formed; the controller switches back to the second excitation current to restore the lockout, and then switches back to the first excitation current; if a second separation detection signal is generated again before the steady state is formed, the brief lockout states formed during the first and second first excitation current control are not used to support the reduction of the first excitation current.

[0070] If the above recovery process occurs multiple times, and no effective evaluation time of the preset evaluation duration is accumulated within the entire preset statistical period, then the current first excitation current is maintained, or the first excitation current is increased according to the obtained separation detection signal, without reducing the first excitation current due to the repeated occurrence of the brief lockout state.

[0071] Example 3: Electromagnetic lock control device; Figure 6 This is a schematic diagram of the structure of an electromagnetic lock control device provided in an embodiment of this application; the device includes a signal acquisition module, a recovery control module, a steady-state judgment module, an evaluation module, and a current adjustment module.

[0072] The signal acquisition module is used to acquire the separation detection signal of the electromagnetic lock during the process of the electromagnetic lock maintaining the locked state with the first excitation current; the recovery control module is used to switch the electromagnetic lock to the second excitation current to restore the locked state in response to the separation detection signal, and switch back to the first excitation current after restoring the locked state; the steady state judgment module is used to determine whether the electromagnetic lock has entered the steady state corresponding to the first excitation current after each switch to the first excitation current; the evaluation module is used to prohibit the reduction of the first excitation current based on the corresponding locked state when the separation detection signal is acquired again before entering the steady state; the current adjustment module is used to adjust the first excitation current according to the steady state formation and the acquisition of the separation detection signal.

[0073] The electromagnetic lock control device can be implemented by the controller; the controller may include a processor, a memory, an excitation current drive interface, and a status signal input interface; the aforementioned modules can be implemented by the processor executing the program stored in the memory, or by corresponding digital circuits, analog circuits, or a combination of both.

[0074] The electromagnetic lock control device described above and the control process of the aforementioned dynamic monitoring unattended sales system are based on the same concept. The specific implementation process can be found in the aforementioned embodiments, and will not be repeated here.

Claims

1. A dynamic monitoring unattended sales system, characterized in that, Includes electromagnetic locks and controllers; The controller is used to acquire the separation detection signal of the electromagnetic lock during the process of the electromagnetic lock maintaining the locked state with the first excitation current; In response to the separation detection signal, the electromagnetic lock is switched to the second excitation current to restore the locked state, and after the locked state is restored, it is switched to the first excitation current, wherein the second excitation current is greater than the first excitation current. After each switch to the first excitation current, it is determined whether the electromagnetic lock has entered a steady state corresponding to the first excitation current; If the separation detection signal is acquired again before entering the steady state, the reduction of the first excitation current is prohibited based on the lockout state between the switch to the first excitation current and the acquisition of the separation detection signal again. The first excitation current is adjusted based on the formation of the steady state and the acquisition of the separation detection signal.

2. The dynamic monitoring unattended sales system according to claim 1, characterized in that, The step of determining whether the electromagnetic lock has entered a steady state corresponding to the first excitation current includes: Obtain the actual excitation current of the electromagnetic lock after it switches from the second excitation current to the first excitation current; Determine whether the actual excitation current falls within the current range corresponding to the first excitation current; After the actual excitation current enters the current range, it is determined that the current transition of the electromagnetic lock from the second excitation current to the first excitation current has ended.

3. The dynamic monitoring unattended sales system according to claim 2, characterized in that, After determining that the current transition has ended, the controller is further configured to: Acquire magnetic state detection data to characterize the electromagnetic lock holding state; Based on the changes in the magnetic state detection data after the current transition ends, it is determined whether the electromagnetic lock has disengaged from the magnetic state corresponding to the previous second excitation current. After determining that the electromagnetic lock has disengaged from the magnetic state corresponding to the previous second excitation current, it is determined that the electromagnetic lock has entered a steady state corresponding to the first excitation current.

4. The dynamic monitoring unattended sales system according to claim 3, characterized in that, The electromagnetic lock includes an electromagnet, a suction element that cooperates with the electromagnet, and a magnetic state detector. The attracting component is a part that can form a magnetic attraction with the electromagnet under the magnetic force generated by the electromagnet; The magnetic state detector is used to obtain magnetic state detection data between the electromagnet and the attracting component; The controller determines whether the magnetic state corresponding to the previous second excitation current has ended based on the changes in the continuously obtained magnetic state detection data.

5. The dynamic monitoring unattended sales system according to claim 3, characterized in that, If the separation detection signal is acquired again before the electromagnetic lock enters the steady state, the controller is further configured to: Switch the electromagnetic lock back to the second excitation current to restore the locked state; It is prohibited to reduce the first excitation current based on the lockout state formed after the previous switch to the first excitation current, and the separation detection signal obtained again shall be used as the basis for maintaining or increasing the first excitation current.

6. The dynamic monitoring unattended sales system according to any one of claims 1-5, characterized in that, When no steady state corresponding to the first excitation current is formed between two consecutive switching of the electromagnetic lock to the second excitation current, the controller determines the two consecutive second excitation current controls and the first excitation current control between them as the same continuous recovery process.

7. The dynamic monitoring unattended sales system according to claim 6, characterized in that, The controller is also used for: Determine the number of times the electromagnetic lock is switched to the second excitation current during the continuous recovery process; After the continuous recovery process is completed, determine whether the electromagnetic lock reaches a steady state under the first excitation current and the locking status after reaching a steady state; The adjustment direction of the first excitation current is determined based on the number of recovery cycles and the steady-state condition.

8. The dynamic monitoring unattended sales system according to claim 1, characterized in that, The controller is also used to determine the effective evaluation duration of the first excitation current; The effective evaluation time is only the time during which the electromagnetic lock is maintained in a locked state by the first excitation current after it enters a steady state corresponding to the first excitation current. The time corresponding to the second excitation current and the time between switching from the second excitation current to the first excitation current and entering the steady state are not included in the effective evaluation time.

9. The dynamic monitoring unattended sales system according to claim 8, characterized in that, If, within a preset statistical period, the electromagnetic lock generates the separation detection signal again before entering the steady state each time it switches from the second excitation current to the first excitation current, causing the effective evaluation time to fall short of the preset evaluation time, then the controller prohibits reducing the first excitation current.

10. An electromagnetic lock control device, characterized in that, include: The signal acquisition module is used to acquire the separation detection signal of the electromagnetic lock during the process of the electromagnetic lock maintaining the locked state with the first excitation current; The recovery control module is used to respond to the separation detection signal by switching the electromagnetic lock to the second excitation current to restore the locked state, and then switching to the first excitation current after restoring the locked state, wherein the second excitation current is greater than the first excitation current. The steady-state determination module is used to determine whether the electromagnetic lock has entered a steady state corresponding to the first excitation current after each switch to the first excitation current. The evaluation module is used to prevent the reduction of the first excitation current based on the blocking state between the switch to the first excitation current and the reacquisition of the separation detection signal when the separation detection signal is acquired again before entering the steady state. The current adjustment module is used to adjust the first excitation current according to the formation of the steady state and the acquisition of the separation detection signal.

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