Monitoring device and method for refrigerated container

Abstract

The present application relates to monitoring equipment for refrigerated containers and methods thereof. A monitoring equipment for a refrigerated container is provided, comprising: a detection module configured to invert the polarity of a data signal received from the refrigerated container while maintaining a common ground connection and output the signal as a detection signal; and a control module communicatively coupled to the detection module and configured to determine a power supply status of the monitoring equipment, determine whether a detection signal output by the detection module has been received based on the power supply status, and, in response to a determination that a detection signal has been received, activate the monitoring equipment to send a command to the refrigerated container. Numerous other aspects are also provided.

Description

Technical Field

[0001] The present application relates to a monitoring device for a refrigerated container, and in particular to a monitoring device operating under battery power supply. Background Art

[0002] Using monitoring equipment installed on refrigerated containers to monitor their status during ocean transport is a common container management method. Refrigerated containers are often powered by an external power source that provides high-voltage electricity, which in turn powers the monitoring equipment. Generally speaking, when a refrigerated container is disconnected from the external power source, the monitoring equipment often ceases to function due to lack of external power, despite typically including a battery module. During this period, monitoring and management of the refrigerated container is interrupted, potentially leading to numerous issues, such as the loss or replacement of the controller in the refrigerated container. Summary of the Invention

[0003] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0004] In order to overcome the above-mentioned defects of the prior art, the present disclosure provides a monitoring device for a refrigerated container and a method thereof that can be started and operated under battery power, thereby avoiding the interruption of monitoring and management of the refrigerated container due to the monitoring device being in a stopped working state due to being disconnected from an external power supply, and further avoiding problems such as the loss or substitution of the controller in the refrigerated container.

[0005] According to a first aspect of the present disclosure, there is provided a monitoring device for a refrigerated container, comprising: a detection module configured to: invert the polarity of a data signal received from the refrigerated container while maintaining a common ground and output the data signal as a detection signal; a control module communicatively coupled to the detection module and configured to: determine a power supply status of the monitoring device, determine whether the detection signal output by the detection module is received based on the power supply status, and activate the monitoring device to send an instruction to the refrigerated container in response to determining that the detection signal is received.

[0006] In some examples of the first aspect, the detection module further includes a polarity reversal power converter configured to convert a negative voltage into a positive voltage.

[0007] In some examples of the first aspect, the control module is further configured to: determine whether the monitoring device is powered by an external power source or a battery module, and ignore the detection signal output from the detection module in response to determining that the monitoring device is powered by the external power source.

[0008] In some examples of the first aspect, the control module is further configured to: in response to determining that the monitoring device is powered by the battery module, determine whether a detection signal output by the detection module is received, and in response to determining that the detection signal is received, activate the monitoring device to send an instruction to the refrigerated container.

[0009] According to a second aspect of the present disclosure, there is provided a method performed by a monitoring device for a refrigerated container, the monitoring device including a detection module configured to: invert the polarity of a data signal received from the refrigerated container while maintaining a common ground and output the data signal as a detection signal, the method comprising: determining a power supply status of the monitoring device; determining whether the detection signal output by the detection module is received based on the power supply status; and, in response to determining that the detection signal is received, starting the monitoring device to send an instruction to the refrigerated container.

[0010] In some examples of the second aspect, determining the power supply status of the monitoring device includes determining whether the monitoring device is powered by an external power supply or a battery module.

[0011] In some examples of the second aspect, the method further includes: ignoring the detection signal output from the detection module in response to determining that the monitoring device is powered by the external power supply.

[0012] In some examples of the second aspect, the method further includes: in response to determining that the monitoring device is powered by the battery module, determining whether a detection signal output by the detection module is received, and in response to determining that the detection signal is received, starting the monitoring device to send an instruction to the refrigerated container.

[0013] According to a third aspect of the present disclosure, there is provided a computer storage medium having computer executable instructions stored thereon, which, when executed by a processor, causes the processor to implement the method steps as described in the second aspect of the present disclosure.

[0014] Compared with the prior art, the present disclosure adds a detection module to the monitoring equipment for refrigerated containers to detect the data signal of the refrigerated containers, and configures the monitoring equipment to adopt the detection signal output by the detection module based on the current power supply status, so that the monitoring equipment can start working synchronously with the refrigerated container under battery power, thereby avoiding long-term interruption of the monitoring and management of the refrigerated containers and potential problems such as loss or substitution of the controller in the refrigerated container. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above features and advantages of the present disclosure can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or characteristics may have the same or similar reference numerals.

[0016] Figure 1 is a schematic block diagram illustrating a system including a refrigerated container and monitoring equipment according to aspects of the present disclosure;

[0017] Figure 2 is a circuit diagram illustrating a detection module for implementing a monitoring device according to various aspects of the present disclosure;

[0018] Figure 3 is a flow chart illustrating a method for starting a monitoring device under battery power according to aspects of the present disclosure; and

[0019] Figure 4 is a block diagram of an exemplary computer system suitable for implementing some embodiments of the present disclosure. DETAILED DESCRIPTION

[0020] The following specific embodiments of the present disclosure are described. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Although the description of the present disclosure will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present disclosure. In order to provide an in-depth understanding of the present disclosure, the following description will contain many specific details. The present disclosure can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present disclosure, some specific details will be omitted in the description.

[0021] The following embodiments of the technical solution of the present disclosure are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present disclosure and are therefore only examples and are not intended to limit the scope of protection of the present disclosure.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the terms "including" and "having" and any variations thereof in the specification and claims of the present disclosure and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0023] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0024] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] In the description of the embodiments of the present disclosure, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0026] Using monitoring equipment installed on refrigerated containers to monitor their status during ocean transport is a common container management method. Refrigerated containers are often powered by an external power source that provides high-voltage electricity, which in turn powers the monitoring equipment. Generally speaking, when a refrigerated container is disconnected from the external power source, the monitoring equipment often ceases to function due to lack of external power, despite typically including a battery module. During this period, monitoring and management of the refrigerated container is interrupted, potentially leading to numerous issues, such as the loss or replacement of the controller in the refrigerated container.

[0027] Specifically, in the case of interrupted monitoring and management of refrigerated containers, the monitoring equipment is typically powered when the refrigerated container is connected to an external power source. At this point, the monitoring equipment activates, sends commands to, and interacts with, the controller within the refrigerated container, collecting and reporting information such as set temperature, supply air temperature, return air temperature, ambient temperature, compressor status, controller fault codes, controller time, controller serial number, controller software version number, and controller hardware version number. When the refrigerated container is disconnected from the external power source and unable to power the monitoring equipment, the monitoring equipment often ceases to function, disrupting monitoring and management of the refrigerated container.

[0028] Specifically, regarding the loss or substitution of controllers in refrigerated containers, there are two common scenarios in the industry: theft, meaning the controller is completely lost; and substitution, meaning the new controller is replaced with the old one. According to the refrigerated container transportation process, after transport, the shipper or freight forwarder's fleet typically returns the refrigerated container to the empty container yard designated by the shipowner and conducts equipment handover. This equipment handover includes a manual inspection, which is currently the primary solution and method for preventing controller theft. Controller theft primarily occurs during storage at empty container yards, making it difficult to verify the theft and trace back to the original location. Controller substitution, which typically occurs when the refrigerated container is returned empty after use, involves the thief removing the new controller and replacing it with the old one. This substitution is difficult to detect through manual inspection. Furthermore, controller substitution is more common than theft, as controller theft occurs at supervised and managed yards.

[0029] To this end, the present disclosure provides a monitoring device and method thereof that can start working without an external power supply (i.e., powered by a battery), thereby avoiding interruption of monitoring and management of refrigerated containers due to being in a stopped state, and further avoiding problems such as loss or substitution of controllers in refrigerated containers.

[0030] According to one aspect of the present disclosure, a monitoring device for a refrigerated container is provided. Figure 1 , Figure 1 1 is a schematic block diagram illustrating a system 100 including a refrigerated container and monitoring equipment according to various aspects of the present disclosure. Figure 1 As shown in FIG, the system 100 includes an external power source, a refrigerated container 101 and a monitoring device 110.

[0031] According to some aspects, the refrigerated container 101 may include a controller 102. In some examples, the controller 102 may communicate with various components in the refrigerated container 101 (such as a compressor, a condenser, a condenser fan, an evaporator, an evaporator fan, an electronic expansion valve, and a control valve, etc. (for simplicity) Figure 1101 and its components. The controller 102 may be communicatively coupled to and control the operation of these components (not all shown). In some examples, the controller 102 may exchange data signals with the monitoring device 110 via a data connection, for example, receiving status data collected by various sensor modules in the monitoring device 110, receiving commands from the monitoring device 110 for controlling the operation of the refrigerated container 101 and its various components, transmitting feedback signals to the monitoring device 110, and so on. In some examples, the refrigerated container 101 is powered by an external power source, which further supplies power to the monitoring device 110 via a cable. In some examples, the controller 102 may include a controller battery 103. In some examples, when disconnected from an external power source, the refrigerated container 101 may periodically (e.g., every hour) wake up to perform operations such as logging, supported by the controller battery 103. In some examples, a negative voltage may be present at the data transmission port on the refrigerated container controller when the refrigerated container 101 periodically wakes up to perform operations.

[0032] According to some aspects, monitoring device 110 can be powered by refrigerated container 101 via a cable. In some examples, when refrigerated container 101 is disconnected from an external power source, it is unable to power monitoring device 110, causing monitoring device 110 to cease operation. In other words, although monitoring device 110 includes battery module 113, monitoring device 110 generally only operates when powered by an external power source.

[0033] In some examples, the monitoring device 110 may exchange data signals with the refrigerated container 101 via a data connection, as described above. In some examples, the monitoring device 110 may include a control module 112, a battery module 113, a sensor module, a communication module, a positioning module, a data parsing module, a storage module, etc., which are communicatively coupled to each other (for simplicity). Figure 1 In some examples, the monitoring device 110 may be connected to a remote server via a wireless network, and the server may be provided with, for example, a data receiving and distribution module, a monitoring platform module, a statistical analysis module, etc. ( Figure 1 (not shown). In some examples, when monitoring device 110 is activated and in operation, the sensor module, positioning module, etc. in monitoring device 110 collect time, location, temperature, humidity, and other sensor data during the operation of the refrigerated container, and transmit them back to the server via the communication module. An example of monitoring device 110 cited in this disclosure can be found, for example, in Chinese Patent No. ZL201610301840.0, entitled "A Multifunctional Refrigerated Container Safety Monitoring Device," the contents of which are expressly incorporated herein by reference in their entirety for all applicable purposes.

[0034] According to some aspects of the present disclosure, monitoring device 110 may further include a detection module 111. In some examples, detection module 111 may receive a data signal from refrigerated container 101 via a data connection. For example, when refrigerated container 101 is powered by controller battery 102 and periodically wakes up to perform operations, resulting in a negative voltage at the data transmission port on the refrigerated container controller side, detection module 111 may receive this negative voltage input signal from refrigerated container 101 via the data connection. In some examples, detection module 111 may invert the polarity of the data signal received from the refrigerated container while maintaining a common ground, and output the signal as a detection signal to control module 112.

[0035] Next reference Figure 2 An example implementation of the detection module 111 is described below. Figure 2 is an exemplary circuit diagram illustrating a method for implementing the detection module 111 in the monitoring device 110 according to various aspects of the present disclosure. Figure 2 In the example, the detection module 111 may further include a polarity reversal power converter configured to reverse the polarity of the input signal. In some examples, the polarity reversal power converter may be provided by, for example, a low-power polarity reversal power converter ICL7660 produced by Maxim, which is typically used for power polarity conversion. In the example using ICL7660, the quiescent power consumption of the polarity reversal power converter is 170uA, the input voltage is 1.5-10V, and the operating frequency is 10KHz. The ICL7660 is characterized by low power consumption and simple peripheral circuits, and can achieve a conversion efficiency of up to 98%. As known to those skilled in the art, the polarity reversal power converter is generally used to convert an input positive voltage into a negative voltage. According to some aspects of the present disclosure, the polarity reversal power converter is configured to convert a negative voltage received from the refrigerated container controller side into a positive voltage and keep the circuit common ground, thereby achieving negative voltage detection.

[0036] Specific reference Figure 2 , the TX on the left is the transmission signal from the refrigerated container controller. In one example, the voltage level on the RS232 data connection line is around -5V, and the signal is a negative voltage relative to the ground level GND. Figure 2In the example, the negative voltage input signal is rectified by D1, current limited by R1, filtered by C1 and C2, and then connected to the 3rd pin of U1 as the ground level (V-) of U1. The original ground level GND is connected to the power supply pin of U1. For U1, the 8th pin is still a positive voltage supply relative to the 3rd pin. The charge pump inside U1 charges C3 to the GND level (relative to the V- level of U1's 3rd pin). During the conversion cycle, the voltage on C3 plus the power supply voltage GND of the 8th pin charges C4 to 2 times the GND level through D2, that is, the voltage V+ on C4 is 2 times GND (the power supply voltage of U1) relative to the 3rd pin V- of U1. Therefore, V+ is the power supply voltage of U1 relative to the GND level. Assuming that the level from TX is -5V, the voltage of V+ is -TX, that is, +5V (the voltage drop of D1 and D2 is ignored at this time). In Figure 2 In the example, V+ can be used as a negative voltage detection signal (V-SIG) after being divided by R2 and R3 for subsequent use. Figure 2 As can be seen from the circuit diagram, through Figure 2 The detection module implemented by the circuit diagram shown can convert the voltage polarity without changing the characteristics of the circuit common ground, thereby not affecting the subsequent circuit receiving data from the TX.

[0037] Those skilled in the art should understand that Figure 2 The circuit diagram shown in is only an example, and any other suitable circuit may be used to implement the detection module described in the present disclosure without departing from the spirit and scope of the present disclosure, as long as it can detect the data signal on the refrigerated container controller side and activate the monitoring device to work.

[0038] In some examples, the control module 112 of the monitoring device 110 can determine the power supply status of the monitoring device 110. For example, the control module 112 can determine whether the monitoring device is powered by an external power source or a battery module. In some examples, the control module 112 can determine whether a detection signal output by the detection module 111 has been received based on the power supply status. For example, the control module 112 can ignore the detection signal output by the detection module 111 in response to determining that the monitoring device 110 is powered by an external power source. As another example, the control module 112 can determine whether a detection signal output by the detection module 111 has been received in response to determining that the monitoring device 110 is powered by the battery module 113. In some examples, the control module 112 can activate the monitoring device 110 to send a command to the refrigerated container 101 in response to receiving the detection signal output from the detection module 111. According to some aspects of the present disclosure, the control module 112 of the monitoring device 110 can control the operation of the monitoring device 110 accordingly by using the detection module 111 to detect the presence of a data signal from the controller 102 of the refrigerated container 101. That is, when the refrigerated container 101 is powered by the controller battery 102 to periodically wake up to perform operations and a negative voltage is present at the data transmission port on the refrigerated container controller side, the monitoring device 110, which was originally in a stopped working state due to being disconnected from the external power supply, can respond to the presence of the negative voltage input signal and start up synchronously with the refrigerated container 101 and enter a working state (for example, to send instructions to the refrigerated container 101 and interact with it).

[0039] It should be understood by those skilled in the art that Figure 1 and Figure 2 The various parameters, models, features, etc. described are merely exemplary, and any other suitable parameters, models, features may be equally applicable to the various embodiments described above without departing from the spirit and scope of the present disclosure.

[0040] Compared with the prior art, the monitoring device according to the present invention, when powered by a battery, starts up immediately upon detecting the periodic awakening of the refrigerated container and sends instructions to and interacts with the refrigerated container, such as transmitting the set temperature, supply air temperature, return air temperature, ambient temperature, controller serial number, etc., thereby realizing the monitoring and management of the refrigerated container during a power outage (disconnected from the external power supply), and avoiding long-term interruption of the monitoring and management of the refrigerated container.

[0041] In addition, the monitoring device according to the present disclosure is started synchronously with the refrigerated container when it wakes up, that is, as long as the battery of the controller of the refrigerated container has power, the monitoring device will record the status of the refrigerated container after each wake-up and form an audit record based on this (including data such as time, longitude and latitude, controller parameters, etc.). This is particularly effective in avoiding or reducing the risk of theft and substitution of the refrigerated container controller, as long as the battery of the controller of the refrigerated container has power. Specifically, in the case of the controller being lost, the approximate time period of loss can be traced back based on the audit record, and based on this, for example, video surveillance or entry and exit records of the yard can be checked in a targeted manner. In the case of controller substitution, since the substitution usually occurs when the empty container is returned, and since the empty container is returned just after the refrigerated container completes the transportation task, the controller battery is now fully charged due to the presence of the external power supply (which simultaneously supplies power to the refrigerated container and charges the controller battery). Therefore, in the case of controller substitution, the change in the controller serial number can be determined based on the audit record, an alarm message can be generated, and a series of subsequent actions and measures can be followed up.

[0042] According to another aspect of the present disclosure, a method performed by a monitoring device for a refrigerated container is provided. Figure 3 , Figure 3 3 is a flow chart illustrating a method 300 for starting a monitoring device under battery power according to aspects of the present disclosure. The method 300 may be performed by, for example, referring to Figure 1 The control module 112 in the monitoring device 110 described above executes and Figure 1 and Figure 2 The description is provided in the context of a system comprising a refrigerated container and a monitoring device.

[0043] like Figure 3As shown in , method 300 may include, at step 305, determining the power status of the monitoring device. In some examples, step 305 may include determining whether the monitoring device is powered by an external power source or a battery module. In some examples, if step 305 determines that the monitoring device is powered by an external power source, method 300 may proceed to step 310 and ignore the detection signal output by the detection module. In some examples, if step 305 determines that the monitoring device is powered by the battery module, method 300 may proceed to step 315. In some examples, method 300 may include, at step 315, determining whether a detection signal output by the detection module is received, i.e., determining whether the refrigerated container periodically wakes up, such that a negative voltage input signal is present on the refrigerated container controller side. If step 315 determines that a detection signal is received, method 300 proceeds to step 320, where the monitoring device is activated to send a command to the refrigerated container. If step 315 determines that no detection signal is received, i.e., no negative voltage input signal is present on the refrigerated container controller side (thereby indicating that the refrigerated container is not awake), method 300 returns to step 305.

[0044] According to yet another aspect of the present disclosure, a computer storage medium having computer executable instructions stored thereon is provided. When the computer executable instructions are executed by a processor, the processor is caused to implement the method steps as described in the above aspects of the present disclosure.

[0045] Next reference Figure 4 , Figure 4 is a block diagram of an exemplary computer system 012 suitable for implementing some embodiments of the present disclosure. Figure 4 The computer system 012 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0046] like Figure 4 As shown, computer system 012 is implemented as a general-purpose computing device. Components of computer system 012 may include, but are not limited to, one or more processors or processing units 016, a system memory 028, and a bus 018 that connects various system components (including system memory 028 and processing units 016).

[0047] Bus 018 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures. Examples of these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0048] The computer system 012 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer system 012, including volatile and non-volatile media, removable and non-removable media.

[0049] System memory 028 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 030 and / or cache memory 032. Computer system 012 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 034 may be used to read and write non-removable, non-volatile magnetic media ( Figure 4 Not shown, often called a "hard drive"). Although Figure 4 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 018 via one or more data medium interfaces. The memory 028 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the various embodiments of the present disclosure.

[0050] A program / utility 040 having a set (at least one) of program modules 042 may be stored, for example, in memory 028. Such program modules 042 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may include an implementation of a network environment. Program modules 042 generally implement the functions and / or methods of the embodiments described herein.

[0051] The computer system 012 may also communicate with one or more external devices 014 (e.g., a keyboard, a pointing device, a display 024, etc.). In the present disclosure, the computer system 012 communicates with an external radar device, and may also communicate with one or more devices that enable a user to interact with the computer system 012, and / or any device that enables the computer system 012 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Such communication may be performed through an input / output (I / O) interface 022. Furthermore, the computer system 012 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 020. As shown, the network adapter 020 communicates with other modules of the computer system 012 via the bus 018. It should be understood that although Figure 4Not shown, other hardware and / or software modules may be used in conjunction with computer system 012, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0052] The processing unit 016 executes various functional applications and data processing by running programs stored in the system memory 028, such as implementing the method flow provided by the embodiment of the present disclosure.

[0053] The aforementioned computer program may be provided in a computer storage medium, i.e., the computer storage medium is encoded with the computer program, which, when executed by one or more computers, causes the one or more computers to perform the method flow and / or device operations shown in the above embodiments of the present disclosure. For example, the method flow provided in the embodiments of the present disclosure may be performed by the one or more processors.

[0054] As time goes by and technology develops, the meaning of "medium" becomes more and more extensive, and the dissemination of computer programs is no longer limited to tangible media, but can also be directly downloaded from the Internet, etc. Any combination of one or more computer-readable media can be used.

[0055] A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or device.

[0056] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0057] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0058] Computer program code for performing the operations of the present disclosure may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0059] Those skilled in the art will appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Technicians may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of this disclosure.

[0060] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0061] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read and write information from / to the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside in a user terminal as discrete components.

[0062] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A monitoring device for a refrigerated container, comprising: A detection module configured to: inverting the polarity of a data signal received from the refrigerated container while maintaining a common ground and outputting the signal as a detection signal; a control module communicatively coupled to the detection module and configured to: Determine whether the monitoring device is powered by an external power source or a battery module, In response to determining that the monitoring device is powered by the battery module, determining whether a detection signal output by the detection module is received, and activating the monitoring device to send an instruction to the refrigerated container in response to determining that the detection signal is received; The control module is further configured to: The detection signal output from the detection module is ignored in response to determining that the monitoring device is powered by an external power source.

2. The monitoring device according to claim 1, wherein The detection module further includes a polarity reversing power converter configured to convert a negative voltage into a positive voltage.

3. The monitoring device according to claim 1, wherein: The control module configured to activate the monitoring device to send instructions to the refrigerated container in response to determining that the detection signal is received is further configured to: when activating the monitoring device to send instructions to the refrigerated container, receive a status report from the refrigerated container, the status report including the set temperature, supply air temperature, return air temperature, and ambient temperature.

4. The monitoring device according to claim 3, wherein: The status report includes a controller serial number, and the control module is further configured to: Based at least in part on the audit record, it is determined that the controller serial number is inconsistent with a previously stored controller serial number, generating an alarm message.

5. A method performed by the monitoring device for a refrigerated container according to claim 1, the monitoring device comprising a detection module configured to: invert the polarity of a data signal received from the refrigerated container while maintaining a common ground and output the inverted polarity as a detection signal, the method comprising: determining whether the monitoring device is powered by an external power source or a battery module; In response to determining that the monitoring device is powered by the battery module, determining whether a detection signal output by the detection module is received, and activating the monitoring device to send an instruction to the refrigerated container in response to determining that the detection signal is received; The method further comprises: The detection signal output from the detection module is ignored in response to determining that the monitoring device is powered by an external power source.

6. The method according to claim 5, wherein In response to determining that the detection signal is received, activating the monitoring device to send an instruction to the refrigerated container further includes: When the monitoring device is started to send an instruction to the refrigerated container, a status report is received from the refrigerated container, where the status report includes a set temperature, a supply air temperature, a return air temperature, and an ambient temperature.

7. The method according to claim 6, wherein The status report includes a controller serial number, the method further comprising: Based at least in part on the audit record, it is determined that the controller serial number is inconsistent with a previously stored controller serial number, generating an alarm message.

8. A non-transitory computer storage medium having stored thereon computer-executable instructions that, when executed by a computer, cause the computer to perform the operations of the method of any one of claims 5-7.

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