Cell data communication device with and controlling method thereof

Abstract

A first transceiver that transmits and receives cell information including the voltage of a battery cell; A second transceiver that transmits and receives cell information including cell information transmitted and received from a first transceiver; and A cell information communication device and a control method thereof are introduced, comprising a processor that determines the communication capability of the cell information of the second transceiver based on a reception signal regarding cell information received by the second transceiver for a preset determination time, and controls the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when it is determined that the state is uncommunicable.

Description

Technology Field

[0001] The present invention relates to a cell information communication device and a control method thereof, and more specifically, to a cell information communication device for communicating cell information to perform cell balancing that equalizes the voltage of each cell connected in series constituting a battery module, and to a cell information communication device and a control method thereof that improves battery performance by solving the problem of isolated communication between adjacent BMS semiconductors that is inevitably used due to different voltages between battery modules, and particularly by preventing the loss of data to be transmitted and received due to the external environment. Background Technology

[0003] Vehicles that generate driving output using batteries connected to motors are attracting attention as a recent eco-friendly trend. However, such batteries require high voltage. Therefore, to form a high-voltage battery, low-voltage battery cells are bundled into a single battery module, and these modules are further bundled and connected in series or parallel to form a single battery pack, which is then mounted on the vehicle. In this configuration, the battery pack may include a Battery Management System (BMS) and a cooling device to efficiently manage the battery's temperature, voltage, and current.

[0005] Due to inherent characteristics and differences in manufacturing environments, battery cells exhibit varying capacity performance over time. Consequently, voltage imbalances occur among the series-connected cells that constitute the battery module. This voltage imbalance between cells destabilizes the power supply and shortens the lifespan of the battery pack. Therefore, cell balancing to equalize the voltage of each cell is essential. Conventional BMSs measure the voltage or State of Charge (SOC) of the cells and control the system by discharging the charge of cells with high electrical characteristic values ​​or individually charging cells with low electrical characteristic values. To perform this control, it is necessary to prevent data loss during the communication between the ICs constituting the BMS.

[0008] The matters described above as background technology are intended to enhance understanding of the background of the present invention and are merely technical information that the inventor possessed or acquired during the process of deriving embodiments of the present invention; they should not be construed as an acknowledgment that they constitute prior art already disclosed to persons skilled in the art or to the general public prior to filing. Prior art literature

[0010] (Patent Document 0001) KR 10-1271911 B1 The problem to be solved

[0011] The present invention is proposed to solve the above problems, and aims to provide a cell information communication device and a control method thereof for communicating cell information to perform cell balancing that equalizes the voltage of each cell connected in series constituting a battery module, thereby solving the problem of isolated communication between adjacent BMS semiconductors that is inevitably used due to different voltages between battery modules, and particularly preventing the loss of data to be transmitted and received due to the external environment, thereby improving battery performance.

[0013] The technical challenges are not limited to those described above, and other technical challenges may be derived from the following description. means of solving the problem

[0016] An embodiment of the present invention relates to a cell information communication device, comprising: a first transceiver for transmitting and receiving cell information including the voltage of a battery cell;

[0017] A second transceiver that transmits and receives cell information including cell information transmitted and received from a first transceiver; and

[0018] A cell information communication device may be provided, comprising: a processor that determines the communication capability of the cell information of the second transceiver based on a reception signal regarding cell information received from the second transceiver for a preset determination time, and controls the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when it is determined that the state is uncommunicable.

[0019] The first transceiver may include an insulating element that insulates the communication path between the second transceiver.

[0020] The isolation element may include at least one of a transformer and a capacitor.

[0021] The processor can determine the communication capability based on a representative value of the received signal magnitude regarding the cell information of the second transceiver.

[0022] The processor can control the strength of the transmission signal by changing at least one of the current and the voltage related to the transmission signal of the first transceiver.

[0023] The processor can control the strength of the received signal by changing the resistance regarding the received signal of the second transceiver.

[0024] The processor can determine the communication capability of the second transceiver based on the result of controlling the reception sensitivity of the second transceiver, and if it determines again that the communication capability is non-transmissionable, it can control the strength of the transmission signal of the first transceiver.

[0025] Cell information may include at least one of the voltage of the battery cell, the current flowing through the battery cell, the amount of change in current flowing through the battery cell over time, the duration for which the amount of change in current is maintained, the voltage difference between cells, a cell identification number specifying the test cell on which cell balancing is performed, and the State of Charge (SOC) of the battery cell.

[0027] An embodiment according to the present invention comprises a method for controlling a cell information communication device, wherein the method includes the step of determining, based on a signal received by the second transceiver, the communication capability of a first transceiver that transmits and receives cell information including the voltage of a battery cell, or a second transceiver that transmits and receives cell information including the cell information transmitted and received by the first transceiver; and

[0028] A control method for a cell information communication device may be provided, comprising the step of controlling the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when the processor determines that the second transceiver is in a state where communication is impossible.

[0029] The first transceiver may include an insulating element that insulates the communication path between the second transceiver.

[0030] The determination step can determine the communication capability based on the representative value of the received signal magnitude regarding the cell information of the second transceiver.

[0031] The controlling step can control the strength of the transmission signal by changing at least one of the current and the voltage related to the transmission signal of the first transmitting and receiving unit.

[0032] The controlling step can control the strength of the received signal by changing the resistance regarding the received signal of the second transceiver.

[0033] The controlling step can re-determine the communication capability of the second transceiver based on the result of controlling the reception sensitivity of the second transceiver, and if it is determined again to be in a communication capability state, control the strength of the transmission signal of the first transceiver.

[0035] An embodiment of the present invention may provide a computer-readable recording medium on which a program for performing a control method of a cell information communication device is recorded. Effects of the invention

[0037] According to the cell information communication device and the control method thereof of the present invention,

[0038] First, in a cell information communication device for communicating cell information to perform cell balancing that equalizes the voltage of each cell connected in series constituting a battery module, the problem of isolated communication between adjacent BMS semiconductors, which is inevitably used due to different voltages between battery modules, is resolved.

[0039] Second, it prevents the loss of data to be transmitted and received, particularly due to the external environment.

[0040] Third, it can improve battery performance.

[0042] The technical effects are not limited to those described above, and other technical effects may be derived from the following description. Brief explanation of the drawing

[0044] FIG. 1 is a diagram showing communication between a BMS semiconductor and a battery constituting a cell information communication device according to one embodiment of the present invention. FIG. 2 is a diagram showing communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention. FIG. 3 is a diagram showing isolated communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention. FIG. 4 is a drawing showing a cell information communication device according to an embodiment of the present invention. FIG. 5 is a diagram showing a control mechanism of a cell information communication device according to an embodiment of the present invention. FIG. 6 is a diagram showing the results of controlling a cell information communication device according to an embodiment of the present invention. FIG. 7 is a diagram showing the results of controlling a cell information communication device according to another embodiment of the present invention. FIG. 8 is a flowchart illustrating a control method of a cell information communication device according to an embodiment of the present invention. Specific details for implementing the invention

[0045] Specific structural or functional descriptions of embodiments of the present invention disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the present invention, and embodiments according to the present invention may be implemented in various forms and should not be interpreted as being limited to the embodiments described in this specification or application.

[0046] Furthermore, to clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification. Also, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0047] Furthermore, in the detailed description below, the designation of components as "first," "second," etc., is intended to distinguish them based on their identical nature, and is not strictly limited to that order. For instance, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0048] And, throughout the specification, when a part is described as "comprising" or "having" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. That is, in this specification, the terms "comprising" or "having" are intended to specify the existence of the described features, areas, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, areas, numbers, steps, actions, components, parts, or groups of combinations thereof.

[0049] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted.

[0050] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0052] FIG. 1 is a diagram showing communication between a BMS semiconductor and a battery constituting a cell information communication device according to an embodiment of the present invention, FIG. 2 is a diagram showing communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention, FIG. 3 is a diagram showing isolated communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention, FIG. 4 is a diagram showing a cell information communication device according to an embodiment of the present invention, and FIG. 5 is a diagram showing a control mechanism of a cell information communication device according to an embodiment of the present invention.

[0054] FIG. 1 is a diagram illustrating communication between a BMS semiconductor and a battery that constitutes a cell information communication device according to an embodiment of the present invention. As shown in FIG. 1, a battery module (200) is composed of individual cells (100) connected in series. The battery modules (200) and the battery modules (200) can be connected and coupled by a metal bar. One BMS semiconductor (300) per battery module (200) can manage the state of the battery. At this time, the BMS semiconductor (300) can be connected to each cell as many times as the number of senseable channels. Through communication with the battery cell (100), the BMS semiconductor (300) senses cell information including the measured voltage or SOC (State of Charge) of the cell, and controls the consumption of the charge of a cell with a high electrical characteristic value or the individual charging of a cell with a low electrical characteristic value based on the sensed cell information or the processing information obtained by processing the cell information.

[0056] FIG. 2 is a diagram showing communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention, and the BMS semiconductor (300) of the cell information communication device according to an embodiment of the present invention may include an insulating element that insulates the communication path between other BMS semiconductors (300). The insulating element may include at least one of a transformer and a capacitor.

[0057] As shown in FIG. 2, N ICs (Integrated Circuits) on BMS semiconductors (300) communicate cell information received through communication with the battery (200) with ICs on other BMS semiconductors (300). Additionally, ICs that are part of the BMS semiconductors (300) (IC #1 shown in FIG. 2) communicate with a processor including a microcontroller (uC) to transmit or receive sensed cell information or processing information that has processed cell information.

[0058] At this time, due to differences in intrinsic characteristics and manufacturing environments, the battery cells may show differences in performance as they are used, and as a result, cell information including voltage between one battery cell and another battery cell may differ. Accordingly, cell information including voltage accepted by each IC on the BMS (300) also becomes different. Therefore, communication between an IC on the BMS semiconductor (300) and an adjacent IC on the BMS semiconductor (300) requires preventing the DC influence of the signal transmitted according to this different cell information. Accordingly, an isolation element may be used for communication between ICs. As shown in FIG. 2, the isolation element that isolates the communication path between ICs may include at least one of a transformer and a capacitor.

[0060] FIG. 3 is a diagram illustrating isolated communication between a BMS semiconductor and a BMS semiconductor constituting a cell information communication device according to an embodiment of the present invention. In the cell information communication device according to an embodiment of the present invention, the isolation elements may include a transformer and a capacitor. As shown in FIG. 3, let's assume that IC #1 of the BMS semiconductor (300) transmits cell information and IC #2 receives cell information. At this time, IC #1 transmits a logic level signal. Subsequently, the signal may pass through an RC filter to block noise. Then, the signal that has passed through the RC filter passes through an isolation capacitor (302), which is one of the isolation elements, and the change in voltage is converted into current. The conversion can be expressed by the mathematical formula i = C dV / dt. In particular, the DC component of the signal disappears due to the isolation capacitor shown in FIG. 3. Subsequently, the signal is transmitted to IC #2 as an induced current equal to the winding ratio of the transformer (304), which is one of the isolation elements. The induced current is again converted into voltage by passing through an isolation capacitor (302), which is one of the isolation elements. Subsequently, the signal passes through an RC filter for noise blocking, and only the AC component of the signal is finally transmitted from IC #1 to IC #2.

[0062] FIG. 4 is a diagram showing a cell information communication device according to an embodiment of the present invention. A cell information communication device according to an embodiment of the present invention may provide a cell information communication device comprising: a first transceiver (301) for transmitting and receiving cell information including the voltage of a battery cell; a second transceiver (303) for transmitting and receiving cell information including the cell information transmitted and received by the first transceiver; and a processor for determining the communication capability regarding the cell information of the second transceiver (303) for a preset determination time based on a reception signal regarding the cell information received by the second transceiver (303), and controlling the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when it is determined to be in a communication capability state. In addition, in a cell information communication device according to an embodiment of the present invention, the processor may control the strength of the transmission signal by changing at least one of the current (308) regarding the transmission signal of the first transceiver (301) and the voltage regarding the transmission signal. The processor can control the strength of the received signal by changing the resistance (306) regarding the received signal of the second transceiver (303). In other words, the processor can control the strength of the received signal by changing the resistance regarding the received signal of the second transceiver. That is, the processor enables communication of the second transceiver, which is in a state of being unable to communicate, through control.

[0063] Each IC on the BMS semiconductor can transmit and receive cell information through a mechanism as shown in Fig. 3. However, the cell information intended to be transmitted and received may be lost due to changes in the external environment. As one of the external environmental changes, the cell voltage or cell current included in the cell information transmitted and received by the IC cannot be transmitted and received accurately as intended in the design due to the different characteristics produced on the semiconductor wafer. For example, if the voltage of the first transceiver (301) increases due to the characteristics of the semiconductor wafer, it takes a long time for the second transceiver (303) to reach a high voltage according to i = C dV / dt above, and the amount of voltage change decreases, so the magnitude of the received signal of the second transceiver (303) decreases. In addition, due to other external environmental changes, cell information may be lost because of the semiconductor characteristics where the ability to flow current decreases as the temperature increases and the opposite occurs when the temperature decreases. In other words, depending on the external environment change as described above, the 2nd transceiver (303) may be in a state where it cannot receive cell information transmitted by the 1st transceiver (301).

[0065] In such a case, as shown in FIG. 4, when the processor of the cell information communication device according to one embodiment of the present invention determines that communication is impossible, it can increase the strength of the transmission signal of the first transmission and reception unit by increasing the strength of the current source (308) of the first transmission and reception unit, or increase the strength of the reception signal by controlling the reception sensitivity by reducing the resistance (306) of the second transmission and reception unit. Accordingly, the cell information communication device according to one embodiment of the present invention prevents loss of cell information to be transmitted and received.

[0067] FIG. 5 is a diagram showing a control mechanism of a cell information communication device according to an embodiment of the present invention. A processor of a cell information communication device according to an embodiment of the present invention can determine the communication capability of the second transceiver (303) based on the result of controlling the reception sensitivity of the second transceiver (303), and if it determines again that the communication capability is non-transmissionable, it can control the strength of the transmission signal of the first transceiver (301). That is, a processor of a cell information communication device according to an embodiment of the present invention can design the control to prevent loss of cell information to be transmitted and received in stages.

[0069] As illustrated in FIG. 5, the transmitter (311) of the first transceiver (301) transmits cell information to the second transceiver (303), and a transformer (304) may be connected as an insulating element that insulates the communication path during this communication. The receiver (333) of the second transceiver (303) receives a reception signal in which an induced current is generated equal to the winding ratio of the transformer (304). The second controller (309) determines the communication capability of the receiver (333) during a preset judgment time. The processor may determine the communication capability of the receiver (333) based on a representative value of the size of the reception signal regarding the cell information of the second transceiver. Here, the representative value may be a maximum value, an interval average value, a weighted average value, a maximum value, a median value, a mode value, etc., but is not limited thereto. If the representative value is greater than or equal to the first reference value, or within the range between the first reference value and the second reference value, it can be considered that the receiving unit (333) has a signal magnitude that can be received, and a judgment can be made based on this.

[0070] Accordingly, when the second controller (309) determines that communication is impossible, the second controller (309) varies the resistance of the receiver (333). Then, during a preset judgment time, the second controller (309) determines that communication is possible. Nevertheless, if the communication impossible state is maintained, or if the transmitter (331) transmits a communication impossible state and inputs it to the first controller (307) via the receiver (313) and determines that communication is impossible, the first controller (307) varies the current of the transmitter (311). Accordingly, the cell information communication device according to one embodiment of the present invention solves the problem of data loss during isolated communication between adjacent BMS semiconductors.

[0072] FIG. 6 is a diagram showing the result of controlling a cell information communication device according to one embodiment of the present invention, FIG. 7 is a diagram showing the result of controlling a cell information communication device according to another embodiment of the present invention, and FIG. 8 is a flowchart showing a method of controlling a cell information communication device according to one embodiment of the present invention.

[0074] FIG. 6 is a diagram showing the result of controlling a cell information communication device according to an embodiment of the present invention, particularly showing the change in the received signal when the current is adjusted in the first transceiver (301). As shown in FIG. 6, assuming that cell information can be communicated only when the strength of the received signal shown by the dotted line is received, the processor of the cell information communication device according to an embodiment of the present invention determines the state of non-communication based on the maximum value, which is one of the representative values ​​of the strength of the received signal, and can confirm that the received signal gradually increases when the current is adjusted in the first transceiver (301).

[0076] FIG. 7 is a diagram showing the result of controlling a cell information communication device according to another embodiment of the present invention, and in particular, shows the change in the received signal when the resistance is adjusted in the second transceiver (301). As shown in FIG. 7, assuming that cell information can be communicated only when the strength of the received signal shown by the dotted line is received, the processor of the cell information communication device according to one embodiment of the present invention determines the state of non-communication based on the maximum value, which is one of the representative values ​​of the strength of the received signal, and can confirm that the received signal gradually increases when the resistance is adjusted in the second transceiver (303).

[0078] Here, cell information may include at least one of the following: voltage of a battery cell, current flowing through a battery cell, current change amount which is the amount of change in the current flowing through the battery cell over time, maintenance time during which the current change amount is maintained, voltage difference between cells, a cell identification number designating a test cell on which cell balancing is performed, and the State of Charge (SOC) of the battery cell. That is, cell information may include information necessary for cell balancing.

[0080] FIG. 8 is a flowchart illustrating a control method for a cell information communication device according to an embodiment of the present invention. The control method for a cell information communication device according to an embodiment of the present invention comprises: a step (S100) of determining, based on a signal received by the second transceiver, the communication capability of a first transceiver that transmits and receives cell information including the voltage of a battery cell, or a second transceiver that transmits and receives cell information including the cell information transmitted and received by the first transceiver, for a preset judgment time; and a step (S200) of controlling the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when the processor determines that the second transceiver is in a state of non-communication. The control step may determine again the communication capability of the second transceiver based on the result of controlling the reception sensitivity of the second transceiver (S300) (S400), and if determined again to be in a state of non-communication, control the strength of the transmission signal of the first transceiver (S500). Subsequently, the judgment mode is released (S600).

[0081] A control method for a cell information communication device according to one embodiment of the present invention can be implemented with an embodiment corresponding to each configuration and technical feature of the cell information communication device described above.

[0083] Furthermore, a method according to various embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either individually or in combination.

[0084] In addition, program instructions recorded on a computer-readable medium may be those specifically designed and configured for the present invention, or may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0087] As described above, one embodiment of the present invention solves the problem of isolated communication between adjacent BMS semiconductors that is inevitably used due to different voltages between battery modules, and in particular prevents the loss of data to be transmitted and received due to the external environment.

[0088] In particular, in a cell information communication device for communicating cell information to perform cell balancing that equalizes the voltage of each cell connected in series constituting a battery module, the loss of data to be transmitted and received due to the external environment is prevented in isolated communication between adjacent BMS semiconductors, which is inevitably used due to different voltages between battery modules. Accordingly, the performance of the battery can be improved.

[0090] Unless otherwise defined, all terms used in the foregoing, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0093] The present invention has been described above with reference to preferred embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of the claims should be interpreted as being included in the invention. Explanation of the symbols

[0097] 100 : Battery cell 200 : Battery module 300: BMS Semiconductor 301: 1st Transmitter / Receiver 302: Insulating capacitor 303: Second Transmitter / Receiver 304: Isolation Transformer 306: Variable resistor 307: First controller 308: Transmitter 309: Second controller 311,331: Transmitter 313,333: Receiver 400: Processor

Claims

Claim 1 A cell information communication device comprising: a first transceiver that transmits and receives cell information including the voltage of a battery cell; a second transceiver that transmits and receives cell information including the cell information transmitted and received by the first transceiver; and a processor that determines the communication capability regarding the cell information of the second transceiver for a preset determination time based on a representative value of the size of the received signal regarding the cell information received by the second transceiver, and controls the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when it is determined to be in a communication capability state. Claim 2 A cell information communication device according to claim 1, characterized in that the first transceiver includes an insulating element that insulates the communication path between the first transceiver and the second transceiver. Claim 3 A cell information communication device according to claim 2, characterized in that the insulating element comprises at least one of a transformer and a capacitor. Claim 4 delete Claim 5 A cell information communication device according to claim 1, characterized in that the processor controls the strength of the transmission signal by changing at least one of the current and the voltage related to the transmission signal of the first transceiver. Claim 6 A cell information communication device according to claim 1, characterized in that the processor controls the strength of the received signal by changing the resistance regarding the received signal of the second transceiver. Claim 7 A cell information communication device according to claim 1, characterized in that the processor determines the communication-enabled state of the second transceiver based on the result of controlling the reception sensitivity of the second transceiver, and controls the strength of the transmission signal of the first transceiver when it determines the communication-unable state again. Claim 8 A cell information communication device according to claim 1, characterized in that the cell information comprises at least one of the voltage of a battery cell, a current flowing through a battery cell, a current change amount which is a change amount of the current flowing through the battery cell over time, a maintenance time during which the current change amount is maintained, a voltage difference between cells, a cell identification number designating a test cell on which cell balancing is performed, and the State of Charge (SOC) of the battery cell. Claim 9 A control method for a cell information communication device comprising: a step of determining, for a preset determination time, the communication capability of a first transceiver that transmits and receives cell information including the voltage of a battery cell in a processor, or a second transceiver that transmits and receives cell information including the cell information transmitted and received by the first transceiver; and a step of controlling the strength of the transmission signal of the first transceiver or the reception sensitivity of the second transceiver when the processor determines that the second transceiver is in a communication-incapable state. Claim 10 A control method for a cell information communication device according to claim 9, characterized in that the first transceiver includes an insulating element that insulates the communication path between the first transceiver and the second transceiver. Claim 11 delete Claim 12 A control method for a cell information communication device according to claim 9, wherein the controlling step controls the strength of a transmission signal by changing at least one of a current and a voltage related to a transmission signal of a first transceiver. Claim 13 A control method for a cell information communication device according to claim 9, wherein the controlling step controls the strength of a received signal by changing the resistance of the received signal of the second transmitting and receiving unit. Claim 14 A method for controlling a cell information communication device according to claim 9, wherein the controlling step is characterized by re-determining the communication-enabled state of the second transceiver based on the result of controlling the reception sensitivity of the second transceiver, and if it is re-determined to be in a communication-unable state, controlling the strength of the transmission signal of the first transceiver. Claim 15 A computer-readable recording medium having a program recorded thereon for performing any one of the methods of claims 9 to 10 and 12 to 14.

Images