Communication control device, communication control method, and communication control program

Abstract

A communication control device (50) configured so as to control communication between a central unit (2) as a master device and a sensor unit (3) as a slave device in a sensor system (1) provided with the central unit (2) and the sensor unit (3) is provided with: a sensitivity acquisition unit (51); acquiring whether the setting state of the sensitivity in the detection operation in the sensor unit is a specified high-sensitivity state or a low-sensitivity state lower than the high-sensitivity state; and a communication control unit (52) that communicates with a special communication signal, which is a communication signal that is a noise source during the detection operation, in a low-sensitivity state instead of a high-sensitivity state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Japanese Patent Application No. 2022-79069 filed on May 12, 2022, and incorporates the entire contents herein. Technical Field

[0003] The present disclosure relates to a communication control device, a communication control method, and a communication control program for controlling communication between a central unit and a sensor unit in a sensor system including a central unit as a master device and a sensor unit as a slave device. Background Art

[0004] For example, Patent Document 1 discloses a method for operating a sensor device in a vehicle based on the DSI protocol. DSI is the abbreviation of Distributed System Interface. The sensor device has a central unit as a host device and a plurality of sensor units as slave devices controlled by the host device. The central unit and the sensor units are connected via a bus cable. Communication between the central unit and the sensor units is performed via the bus cable.

[0005] Patent Document 1: Japanese Patent No. 6894043

[0006] Noise may be generated during communication between the central unit as the master device and the sensor unit as the slave device. Such noise may cause erroneous detection in the sensor unit. On the other hand, if the central unit and the sensor unit are not communicated at all during the detection operation in the sensor unit, the detection operation cycle becomes longer, so there is a limitation in the detection performance. Summary of the invention

[0007] The present disclosure has been made in view of the above-mentioned circumstances, etc. That is, the present disclosure provides, for example, a technique for avoiding erroneous detection in a sensor unit even when communication that becomes a noise source is performed during a detection operation in the sensor unit.

[0008] The communication control device is configured to control communication between the central unit as a master device and the sensor unit as a slave device in a sensor system including the central unit as a master device and the sensor unit as a slave device.

[0009] According to one aspect of the present disclosure, a communication control device includes:

[0010] a sensitivity acquisition unit that acquires whether a setting state of the sensitivity in the detection operation in the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0011] The communication control unit communicates the special communication signal, which is a communication signal that is a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

[0012] According to another aspect of the present disclosure, a communication control method is a method for controlling communication between a central unit as a host device and a sensor unit as a slave device in a sensor system, and the method includes the following processing, namely, including:

[0013] obtaining whether the setting state of the sensitivity in the detection operation of the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0014] The special communication signal, which is a communication signal that is a noise source in the detection operation, is communicated in the low-sensitivity state instead of the high-sensitivity state.

[0015] According to another aspect of the present disclosure, the communication control program is a computer program executed by a communication control device configured to control communication between a central unit as a host device and a sensor unit as a slave device in a sensor system including the central unit as a host device and the sensor unit as a slave device.

[0016] The processing performed by the communication control device includes:

[0017] a sensitivity acquisition process for acquiring whether the setting state of the sensitivity in the detection operation in the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0018] The communication control process communicates the special communication signal, which is a communication signal that becomes a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

[0019] In addition, in each column of the application document, there are cases where each element is attached with a reference figure mark in brackets. However, such a reference figure mark only shows an example of the correspondence between the element and the specific unit described in the embodiment described later. Therefore, the present disclosure is not limited in any way by the description of the above-mentioned reference figure marks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a plan view showing a schematic configuration of a vehicle equipped with a sensor system including the communication control device according to the embodiment.

[0021] Figure 2 Yes means Figure 1 A block diagram showing a schematic functional configuration of the sensor system shown.

[0022] Figure 3 Yes means Figure 2 A block diagram showing a schematic functional configuration of a communication control device included in the sensor system shown.

[0023] Figure 4 Yes means Figure 2 A timing diagram showing a specific example of signal communication in a sensor system is shown.

[0024] Figure 5 Yes means Figure 2 A flowchart of a specific operation example in the sensor system shown. DETAILED DESCRIPTION

[0025] (Implementation Method)

[0026] Hereinafter, the embodiments of the present disclosure will be described based on the accompanying drawings. It should be noted that the records of the drawings, the corresponding device configurations and their functions or actions described below are simplified records in order to briefly describe the contents of the present disclosure, and do not limit the contents of the present disclosure in any way. Therefore, the exemplified configurations shown in the drawings are certainly not necessarily the same as the specific configurations actually manufactured and sold. That is, unless the applicant explicitly limits it through the application process of this application, etc., the present disclosure is certainly not limited to the records of the drawings, the corresponding device configurations and their functions or actions described below. Thus, various modifications can be applied to the embodiments described below. However, if a modification is inserted in the middle of a series of descriptions related to the embodiments, there is a concern that it will hinder the understanding of the embodiments. Therefore, the modifications are recorded collectively after the description of the embodiments.

[0027] (Overall structure of sensor system)

[0028] If you refer to Figure 1 , the sensor system 1 of this embodiment has a configuration as a vehicle-mounted system that performs various functions by being mounted on a vehicle C as a mobile body. The vehicle C is a so-called four-wheeled vehicle that travels on the ground, that is, on the road, and has a box-shaped vehicle body C1 that is roughly rectangular in a plan view. The shape of each part of the vehicle C when viewed "from above" refers to the shape of the part when viewed from a line of sight in the same direction as the direction in which gravity acts when the vehicle C is stably placed on a horizontal surface so that it can travel. The vehicle C equipped with the sensor system 1 of this embodiment is hereinafter referred to as the "own vehicle".

[0029] Hereinafter, a virtual straight line passing through the center of the vehicle in the vehicle width direction and parallel to the vehicle length direction of the vehicle when viewed from above will be referred to as the vehicle width centerline LC. In addition, the vehicle width centerline LC can also be referred to as the vehicle centerline. The vehicle length direction is a direction that is orthogonal to the vehicle width direction and to the vehicle height direction, and can also be referred to as the vehicle length direction. The vehicle height direction is a direction that defines the vehicle height of the vehicle, and is a direction parallel to the direction of gravity when the vehicle is stably placed on a horizontal plane so that it can travel. In addition, Figure 1 In the diagram, "front", "rear", "left", "right" and "up" are defined as indicated by arrows. That is, the vehicle length direction is synonymous with the front-rear direction. In addition, the vehicle width direction is synonymous with the left-right direction.

[0030] The sensor system 1 includes a central unit 2 as a host device and a sensor unit 3 as a slave device. One central unit 2 is provided for one sensor system 1. In contrast, a plurality of sensor units 3 can be provided for one sensor system 1. In the present embodiment, the sensor system 1 has a configuration as a communication system that complies with the DSI3 standard. The central unit 2 and the sensor unit 3 are connected via a communication line 4 in a manner that enables mutual communication of information or signals. The central unit 2 and the plurality of sensor units 3 can be connected by any connection method such as a bus type, a daisy chain type, a star type, etc. Moreover, the sensor system 1 is configured to be able to switch between a command response mode and a periodic data collection mode. Hereinafter, the command response mode is referred to as "CRM mode" and the periodic data collection mode is referred to as "PDCM mode". CRM is the abbreviation of Command and Response Mode. PDCM is the abbreviation of Periodic Data Collection Mode. The CRM mode is equivalent to a first communication mode that enables bidirectional communication between the central unit 2 and the sensor unit 3. The PDCM mode corresponds to a second communication mode in which one-way communication is performed from the sensor unit 3 to the central unit 2 when the sensor unit 3 receives a trigger signal from the central unit 2 .

[0031] In the present embodiment, the central unit 2 has a configuration as an object detection ECU, which uses a sensor unit 3 as an object detection sensor to detect an object B present around the vehicle. ECU is an abbreviation of Electronic Control Unit. The sensor unit 3 is mounted on the vehicle in a manner to receive a reflected wave of a detection wave sent toward the outside of the vehicle and reflected by the object B. The sensor unit 3 is a so-called ranging sensor, and is configured to acquire distance information. The "distance information" is the propagation time from the transmission of the detection wave to the reception of the reflected wave, or the ranging distance calculated based on the propagation time, that is, the estimated distance between the sensor unit 3 and the object B.

[0032] Specifically, the sensor unit 3 is a so-called ultrasonic sensor, and is configured to detect the presence of the object B and the distance to the object B by receiving the reflected wave of the ultrasonic wave, i.e., the detection wave, which is transmitted to the outside and reflected by the object B. In the present embodiment, the sensor unit 3 has a structure of an integrated transmitter and receiver. That is, the sensor unit 3 has a function as a transmitter that transmits the detection wave to the outside, and a function as a receiver that receives the reception wave including the reflected wave of the detection wave reflected by the object B.

[0033] A first front sensor 3A, a second front sensor 3B, a third front sensor 3C, and a fourth front sensor 3D are mounted on a front bumper C2 provided at the front of a body C1 of the vehicle as a sensor unit 3. Similarly, a first rear sensor 3E, a second rear sensor 3F, a third rear sensor 3G, and a fourth rear sensor 3H are mounted on a rear bumper C3 provided at the rear of a body C1 of the vehicle as a sensor unit 3.

[0034] The first front sensor 3A is arranged near the left end of the front bumper C2 to send a transmission wave toward the left front of the vehicle. The second front sensor 3B is arranged between the first front sensor 3A and the vehicle width center line LC in the vehicle width direction to send a transmission wave toward the approximate front of the vehicle. The third front sensor 3C is arranged at a position roughly symmetrical to the second front sensor 3B with the vehicle width center line LC sandwiched therebetween. The third front sensor 3C is arranged between the vehicle width center line LC and the fourth front sensor 3D in the vehicle width direction to send a transmission wave toward the approximate front of the vehicle. The fourth front sensor 3D is arranged near the right end of the front bumper C2 to send a transmission wave toward the right front of the vehicle.

[0035] The first rear sensor 3E is arranged near the left end of the rear bumper C3 to send a transmission wave toward the left rear of the vehicle. The second rear sensor 3F is arranged between the first rear sensor 3E and the vehicle width center line LC in the vehicle width direction to send a transmission wave toward the approximate rear of the vehicle. The third rear sensor 3G is arranged at a position roughly symmetrical to the second rear sensor 3F with the vehicle width center line LC sandwiched therebetween. The third rear sensor 3G is arranged between the vehicle width center line LC and the fourth rear sensor 3H in the vehicle width direction to send a transmission wave toward the approximate rear of the vehicle. The fourth rear sensor 3H is arranged near the right end of the rear bumper C3 to send a transmission wave toward the right rear of the vehicle.

[0036] (Central Unit)

[0037] The central unit 2 is configured as a vehicle-mounted microcomputer having a processor and a memory. Figure 2 The central unit 2 includes a host-side processor 21 , a host-side memory 22 , and a host-side communication unit 23 .

[0038] The host-side processor 21 is configured to perform various control actions by reading and executing programs stored in the host-side memory 22. The host-side memory 22 has at least ROM or non-volatile rewritable memory among various non-migrating physical storage media such as ROM, RAM, and non-volatile rewritable memory. The non-volatile rewritable memory is a storage device that can rewrite information when the power is on, but cannot rewrite information when the power is off, such as a flash memory. In addition to the above-mentioned programs, various parameters such as initial values ​​required when executing such programs are also stored in the host-side memory 22. The host-side communication unit 23 is a communication interface connected to the communication line 4, and is configured to perform communication based on the DSI3 protocol with the sensor unit 3 under the control of the host-side processor 21.

[0039] (Sensor unit)

[0040] Reference Figure 2 The sensor unit 3 includes a sensor side processor 31, a sensor side memory 32, and a sensor side communication unit 33. The sensor side processor 31 is configured to perform overall motion control of the sensor unit 3 by reading and executing a program stored in the sensor side memory 32. The sensor side memory 32 includes at least a ROM or a non-volatile rewritable memory among various non-migratable physical storage media such as a ROM, a RAM, and a non-volatile rewritable memory. In addition, in addition to the above-mentioned programs, various parameters such as initial values ​​required when executing such programs are stored in the sensor side memory 32. The sensor side communication unit 33 is a communication interface connected to the communication line 4, and is configured to perform communication based on the DSI3 protocol with the central unit 2 under the control of the sensor side processor 31.

[0041] In addition, the sensor unit 3 includes a transmitting circuit 34, a receiving circuit 35, and a transceiver 36. The transmitting circuit 34 is configured to apply a driving signal for causing the transceiver 36 to generate a detection wave in a transmitting operation of transmitting a detection wave toward the outside. The receiving circuit 35 is configured to perform various signal processing such as amplification and filtering on a reception signal generated by the transceiver 36 according to the reception state of the reflected wave in a receiving operation of receiving a reflected wave. The transceiver 36 is configured to generate a detection wave by applying a driving signal to the transmitting circuit 34 in a transmitting operation, and to generate a reception signal corresponding to the reception state of the reflected wave in a receiving operation. Specifically, in the present embodiment, the transceiver 36 has a configuration as a so-called resonant type ultrasonic microphone having an electrical-mechanical energy conversion element such as a piezoelectric element built in.

[0042] In this embodiment, the sensitivity of the sensor unit 3 is set to change with the passage of time in the detection operation. That is, the sensor unit 3 is configured to be able to execute STC in which the sensitivity changes with the passage of time from the transmission of the detection wave from the transmitter and receiver 36. STC is an abbreviation of Sensitivity Time Control. Specifically, the sensor side processor 31 performs the STC according to the data stored in the sensor side memory 32. Figure 4 The relationship between time and gain as shown in (i) in FIG. 1 is such that the gain of the amplifier included in the receiving circuit 35 changes with the passage of time.

[0043] (Communication control device)

[0044] Figure 3 Shown in Figure 2 The communication control device 50 is configured to control the communication between the central unit 2 and the sensor unit 3. Specifically, Figure 3 As shown, the communication control device 50 includes a sensitivity acquisition unit 51 and a communication control unit 52 .

[0045] The sensitivity acquisition unit 51 acquires whether the setting state of the sensitivity in the detection action in the sensor unit 3 is a prescribed high sensitivity state or a low sensitivity state lower than the high sensitivity state. Specifically, for example, the sensitivity acquisition unit 51 grasps a low sensitivity interval as a time period of the low sensitivity state. The high sensitivity state and the low sensitivity state are described later. The communication control unit 52 controls the communication timing of the communication signal between the central unit 2 and the sensor unit 3. In this embodiment, the communication control unit 52 communicates the communication signal that becomes a noise source in the detection action of the sensor unit 3, that is, the special communication signal, in a low sensitivity state instead of a high sensitivity state. In addition, the communication control unit 52 communicates a non-special communication signal that is different from the special communication signal in both the high sensitivity state and the low sensitivity state.

[0046] The special communication signal includes a command signal sent from the central unit 2 to the sensor unit 3, and a response signal sent from the sensor unit 3 to the central unit 2 corresponding to the command signal. The non-special communication signal includes a detection result signal corresponding to the result of the detection action of the sensor unit 3. That is, the special communication signal is a communication signal (i.e., CRM signal) sent and received through the first communication mode, i.e., CRM mode. On the other hand, the non-special communication signal is a communication signal (i.e., PDCM signal) sent and received through the second communication mode, i.e., PDCM mode.

[0047] (Action Summary)

[0048] Below, use Figure 4 The timing diagram shown in the figure explains the operation outline of the device configuration, method, and program of this embodiment. In addition, the device configuration, method, and program of this embodiment may be collectively referred to as "this embodiment" in some cases. Figure 4 In the figure, (i) shows the time change of the setting state of the gain in the sensor unit 3, (ii) shows an example of signal communication in the comparative example, and (iii) shows an example of signal communication in the present embodiment. In the figure, G on the vertical axis in (i) is the abbreviation of gain, and t on the horizontal axis represents time. In (ii) and (iii), "M.EXE" is the abbreviation of MeasurementExecute. The MeasurementExecute instruction is a detection start signal for starting the detection action in the sensor unit 3. "MODE" represents the communication mode. The time on the horizontal axis in (i) corresponds to the communication timing and communication mode of each signal in (ii) and (iii), so Figure 4 The same figure shows (i) to (iii).

[0049] The detection start signal as the CRM signal is transmitted from the central unit 2 and received by the sensor unit 3, and the detection operation in the sensor unit 3 is started. In the detection operation, the sensor unit 3 transmits a detection wave from the transceiver 36, and performs an operation of receiving a reflected wave of the detection wave reflected by the object B. In this embodiment, as shown in FIG. Figure 4 As shown in the timing diagram of (i) in FIG. 1 , first, during the period from the start time t0 of the detection action of sending and receiving based on the detection start signal to the time t1 after the prescribed time, the measurement of the electrical noise and acoustic noise in the sensor unit 3 is performed. During the noise measurement period from time t0 to t1, the sensitivity, i.e., the gain, is set to the maximum value Gmax. Next, after the time t1 when the noise measurement ends, the object detection action is performed. The period from time t1 to t2 includes the sending action of the detection wave and the standby time from the end of the sending action to the convergence of the reverberation. During this period, the sensitivity, i.e., the gain, is the minimum value Gmin. After time t2, the receiving action is performed. Here, during the period from time t2 to t3, the sensitivity, i.e., the gain, gradually increases from the minimum value Gmin to the maximum value Gmax, and is maintained at the maximum value Gmax during the prescribed period after time t3. Thus, the sensitivity to the reflected wave from the object B existing in the distance is increased. In addition, the sensor unit 3 sends the PDCM signal corresponding to the reception result of the reflected wave, i.e., the detection result of the object B, to the central unit 2.

[0050] Figure 4 The comparative example shown in (ii) in FIG. 1 shows a case where the present embodiment is not applied. Here, the MeasurementExecute instruction, i.e., the detection start signal, is a CRM signal. Therefore, Figure 4 As shown in the timing diagram of (ii) in the comparative example, at the time of sending and receiving the detection start signal, the communication mode needs to have been switched from the PDCM mode to the CRM mode. On the other hand, in order to receive the PDCM signal from the sensor unit 3, the communication mode needs to be switched to the PDCM mode. Therefore, the central unit 2 sends a mode change signal for changing the communication mode from the CRM mode to the PDCM mode, which is shown as "CRM1" in the figure, to the sensor unit 3. As a result, the communication mode is switched from the CRM mode to the PDCM mode.

[0051] In the PDCM mode, the PDCM signals transmitted from the sensor unit 3 to the central unit 2 and received by the central unit 2 are sequentially numbered in accordance with the time sequence of transmission and reception, such as the PDCM1 signal, the PDCM2 signal, the PDCM3 signal, etc. In addition, in order to avoid the complication of the diagram, the BRC trigger signal, which is a trigger signal transmitted from the central unit 2 to the sensor unit 3 for transmitting the PDCM signal from the sensor unit 3 to the central unit 2, is omitted from the diagram. BRC is the abbreviation of Broadcast Read Command. In addition, in order to change the conditions of the detection action in the sensor unit 3 (for example, the frequency of the detection wave, the transmission and reception cycle, etc.), it is necessary to send a detection condition setting signal from the central unit 2 to the sensor unit 3. The detection condition setting signal is a CRM signal for setting the conditions of the detection action in the sensor unit 3. Therefore, the central unit 2 sends the CRM signal shown as "CRM2" in the figure to the sensor unit 3. The CRM2 signal includes a mode change signal for changing the communication mode from the PDCM mode to the CRM mode, and a detection condition setting signal that is effective after the transmission and reception of such a mode change signal.

[0052] However, noise may be generated during communication between the central unit 2 as a master device and the sensor unit 3 as a slave device. Here, the communication that may become a noise source mainly includes the transmission of instructions from the central unit 2 to the sensor unit 3 and the transmission of responses from the sensor unit 3 to the central unit 2, which is the communication of signals in the CRM mode. Such noise may cause false detection in the sensor unit 3. Specifically, Figure 4 As shown in (ii) in FIG. 1 , if the CRM2 signal, which is a communication signal that becomes a noise source, is sent and received in a high-sensitivity state with a high gain, there is a concern that false detection may be caused by noise. On the other hand, if the communication between the central unit 2 and the sensor unit 3 is not performed at all during the detection operation in the sensor unit 3, the cycle of the detection operation becomes longer, so there is a limitation in the detection performance.

[0053] Therefore, this embodiment Figure 4As shown in (iii) in the figure, the communication signal, that is, the CRM signal, which is a noise source in the detection action of the sensor unit 3, is communicated in a low-sensitivity state instead of a high-sensitivity state. Here, for example, the "high-sensitivity state" is a state in which the gain is set to be greater than a prescribed gain threshold, and the "low-sensitivity state" is a state in which the gain is set to be less than the gain threshold. Or, for example, the "high-sensitivity state" is a state in which the gain is a maximum value Gmax, and the "low-sensitivity state" is a state in which the gain is less than the maximum value Gmax. In this regard, the sensitivity acquisition unit 51 can, for example, grasp the timing of the generation of the low-sensitivity interval based on the sending and receiving time of the MeasurementExecute instruction. Moreover, the communication control unit 52 sets the sending and receiving timing of the CRM signal within the low-sensitivity interval. Specifically, it is possible to communicate with the CRM signal in the low-sensitivity interval between time t1 and t2 when the gain is set to the minimum value Gmin, that is, in the low-sensitivity interval. Figure 4 The CRM signal including the detection condition setting signal, which is the same as the CRM2 signal in the comparative example (ii) of FIG. 1 , is communicated. Thus, even if the CRM signal that becomes a noise source is communicated during the detection operation in the sensor unit 3, erroneous detection in the sensor unit 3 can be well avoided, and the improvement of the close-range detection performance brought about by shortening the cycle of the detection operation can be achieved.

[0054] This embodiment sends and receives a communication signal that is not likely to become a noise source in the detection operation, that is, a PDCM signal, regardless of the setting state of the sensitivity. Therefore, the PDCM signal can be sent and received not only in a low sensitivity state but also in a high sensitivity state. As a result, the short-range detection performance brought about by shortening the cycle of the detection operation can be further improved.

[0055] In the present embodiment, when a CRM signal is received in the PDCM mode, processing corresponding to the received CRM signal is performed. Figure 4 As shown in (iii) in the figure, the detection start signal can be sent and received regardless of the communication mode. That is, when sending and receiving the detection start signal, there is no need to switch the communication mode from the PDCM mode to the CRM mode. In addition, when sending and receiving the CRM signal containing the detection condition setting signal in the low-sensitivity state during the detection action of the sensor unit 3, there is no need to switch the communication mode from the PDCM mode to the CRM mode. In this way, according to this embodiment, the number of times the mode change signal for switching the communication mode from the PDCM mode to the CRM mode is sent and received can be reduced to suppress the communication volume, and the short-range detection performance brought about by the shortening of the detection action cycle can be further improved.

[0056] In a series of detection actions, that is, from the time when the MeasurementExecute instruction is sent and received to the time when the MeasurementStop instruction is sent and received, consecutive symbols are added to the PDCM signal in sequence according to the time sequence of sending and receiving. The MeasurementStop instruction is a detection end signal for ending the detection action in the sensor unit 3. Here, the present embodiment resets the symbol to be added next time to the initial value by sending and receiving a reset signal as a CRM signal, and on the other hand, resetting to the initial value is prohibited even if a CRM signal different from the reset signal is sent and received. The "reset signal" is a detection start signal or a detection end signal. Specifically, if Figure 4 As shown in (iii), even if a CRM signal is sent or received immediately after a PDCM2 signal, if such a CRM signal is not a reset signal, the PDCM signal immediately following it is also a PDCM3 signal. Thus, even if a CRM signal is sent or received in a low-sensitivity state in a series of detection actions, it is possible to avoid accidentally resetting the serial number symbol attached to the PDCM signal midway. Therefore, according to this embodiment, data from multiple sensor units 3 can be well recovered in the central unit 2.

[0057] This embodiment switches from the CRM mode to the PDCM mode not only when a mode change signal is sent and received, but also when a detection start signal and a detection condition setting signal are sent and received. This can reduce the number of times the mode change signal is sent and received to suppress the communication volume, and can also further improve the close-range detection performance brought about by shortening the detection action cycle.

[0058] Figure 5 The process related to the switching of the communication mode is shown. In addition, in the flowchart shown in the figure, "S" is the abbreviation of "step". Figure 5 The flowchart shown will explain the process related to the switching of the communication mode. First, in step 501, the communication control unit 52 determines whether the current communication mode is the CRM mode.

[0059] When the current communication mode is the CRM mode (i.e., step 501 = Yes), the communication control unit 52 performs the processing of step 502. In step 502, the communication control unit 52 determines whether a ModeChange command, i.e., a mode change signal is transmitted or received. When a mode change signal is transmitted or received (i.e., step 502 = Yes), the communication control unit 52 performs the processing of step 503 and temporarily ends the processing related to the switching of the communication mode. In step 503, the communication control unit 52 switches the communication mode from the CRM mode to the PDCM mode. When there is no transmission or reception of the mode change signal (i.e., step 502 = No), the communication control unit 52 performs the processing of step 504. In step 504, the communication control unit 52 determines whether a MeasurementExecute command, i.e., a detection start signal is transmitted or received. When a detection start signal is transmitted or received (i.e., step 504 = Yes), the communication control unit 52 performs the processing of step 503 and temporarily ends the processing related to the switching of the communication mode. If the detection start signal is not sent or received (i.e., step 504 = No), the communication control unit 52 performs the processing of step 505. In step 505, the communication control unit 52 determines whether the Measurement Setting command, i.e., the detection condition setting signal, is sent or received. If the detection condition setting signal is sent or received (i.e., step 505 = Yes), the communication control unit 52 performs the processing of step 503 and temporarily ends the processing related to the switching of the communication mode. On the other hand, if the detection condition setting signal is not sent or received (i.e., step 505 = No), the communication control unit 52 skips the processing of step 503 and temporarily ends the processing related to the switching of the communication mode.

[0060] When the current communication mode is the PDCM mode (i.e., step 501 = No), the communication control unit 52 performs the processing of step 506. In step 506, the communication control unit 52 determines whether there is a ModeChange instruction, that is, a mode change signal being sent or received. When there is a mode change signal being sent or received (i.e., step 506 = Yes), the communication control unit 52 performs the processing of step 507 and temporarily ends the processing related to the switching of the communication mode. In step 507, the communication control unit 52 switches the communication mode from the PDCM mode to the CRM mode. When there is no mode change signal being sent or received (i.e., step 506 = No), the communication control unit 52 skips the processing of step 507 and temporarily ends the processing related to the switching of the communication mode.

[0061] (Variation Example)

[0062] The present disclosure is not limited to the above-mentioned embodiments. Therefore, the above-mentioned embodiments can be appropriately changed. Representative modified examples are described below. In the following description of the modified examples, the differences from the above-mentioned embodiments are mainly described. In addition, in the above-mentioned embodiments and the modified examples, the same figure marks are attached to the mutually identical or equivalent parts. Therefore, in the description of the following modified examples, with respect to the constituent elements with the same figure marks as those in the above-mentioned embodiments, as long as there is no technical contradiction or special additional description, the description in the above-mentioned embodiment can be appropriately cited.

[0063] The present disclosure is not limited to the specific device configuration shown in the above-mentioned embodiment. That is, for example, the sensor system 1 is not limited to a vehicle-mounted system.

[0064] All or part of the functional components implemented by the host-side processor 21 and the host-side memory 22 in the central unit 2 can be replaced by digital circuits such as ASIC and FPGA. ASIC is the abbreviation of Application Specific Integrated Circuit. FPGA is the abbreviation of Field Programmable Gate Array. That is, in the central unit 2, the vehicle-mounted microcomputer part and the digital circuit part can coexist. The same is true for the sensor unit 3.

[0065] The program of the present disclosure capable of executing the various actions, sequences or processes described in the above embodiments can be downloaded or upgraded via V2X communication. V2X is the abbreviation of Vehicle to X: Internet of Vehicles. Alternatively, such a program can be downloaded or upgraded via a terminal device provided in a manufacturing plant, a maintenance plant, a sales store, etc. of the vehicle C. The storage destination of such a program can also be a memory card, an optical disc, a magnetic disk, etc.

[0066] In this way, the above-mentioned various functional structures and processes can also be implemented by a dedicated computer provided by a processor and a memory programmed to execute one or more functions concretized by a computer program. Alternatively, the above-mentioned various functional structures and processes can also be implemented by a dedicated computer provided by a processor composed of one or more dedicated hardware logic circuits. Alternatively, the above-mentioned various functional structures and processes can also be implemented by one or more dedicated computers composed of a combination of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program can also be stored in a non-migrating physical storage medium that can be read by the computer as an instruction executed by the computer. That is, the above-mentioned various functional structures and processes can also be expressed as a computer program containing a sequence for implementing the various functional structures and processes, or a non-migrating physical storage medium storing the program.

[0067] thus, Figure 3 The sensitivity acquisition unit 51 and the communication control unit 52 shown are functional components that are conveniently set to help understand the contents of the present disclosure. Therefore, even if these functional components are not actually implemented as routines or hardware inside the central unit 2 and / or the sensor unit 3, as long as the functions or processes specified in the present disclosure can be implemented, it will be sufficient.

[0068] The connection method between the central unit 2 as a host device and the sensor unit 3 as a slave device is not limited to DSI, but can also be PSI. PSI is the abbreviation of Peripheral Sensor Interface. There is no special limitation on the versions of DSI and PSI, but it is preferred that they are the latest versions at the implementation time, such as DSI3 and PSI5 at the time of application of this application. In this way, the present disclosure can be widely applied to the time division multiple access connection method, namely the TDMA method. TDMA is the abbreviation of Time Division Multiple Access.

[0069] For example, three sensor units 3 may be mounted on each of the front bumper C2 and the rear bumper C3. Alternatively, five or more sensor units 3 may be mounted on the front bumper C2 and / or the rear bumper C3. Alternatively, for example, the sensor unit 3 may be mounted on the side surface of the vehicle body C1.

[0070] The specific configuration and usage of the sensor unit 3 are not particularly limited. That is, for example, the sensor unit 3 is not limited to an integrated transmitter-receiver type that performs transmission and reception operations through a single transmitter-receiver 36, but may be configured such that a transmitter-receiver 36 for transmission and a transmitter-receiver 36 for reception are independently provided in a single housing. In addition, one of the plurality of sensor units 3 may be used for transmission, and the others may be used for reception. In this case, the sensor unit 3 for transmission and the sensor unit 3 for reception may be appropriately replaced over time.

[0071] The sensor unit 3 is not limited to the so-called ultrasonic sensor. That is, for example, the sensor unit 3 may also be a radar sensor. In addition, the sensor unit 3 is not limited to the so-called distance measuring sensor. Specifically, for example, the sensor unit 3 may also be a collision detection sensor in an airbag system.

[0072] The present disclosure is not limited to the specific operation mode shown in the above embodiment. That is, for example, the change mode of gain or sensitivity over time is not limited to Figure 4 Specific example shown in (i) in FIG. Specifically, for example, the rising mode of the gain during the period from time t2 to t3 is not limited to the step-like shape shown in the figure, but can also be a straight line or a curve. In addition, the sensitivity acquisition unit 51 can also determine whether the setting state of the sensitivity at a specific processing timing of the processor is a high sensitivity state or a low sensitivity state. In this case, the sensitivity acquisition unit 51 can also be called a "sensitivity determination unit".

[0073] "Exceed" and "above" can be interchanged. Similarly, "less than" and "below" can be interchanged. As long as there is no technical contradiction or adverse situation, similar concepts such as "obtain", "calculate", "detect", and "check" can also be interchanged.

[0074] The elements constituting the above-mentioned embodiments are not necessarily essential elements, except for the cases where they are specifically indicated as essential elements and the cases where they are clearly considered as essential elements in principle. In addition, when referring to the number, amount, range and other numerical values ​​of the constituent elements, the present disclosure is not limited to the specific numerical values, except for the cases where they are specifically indicated as essential numerical values ​​and the cases where they are clearly limited to specific numerical values ​​in principle. Similarly, when referring to the shapes, directions, positional relationships and the like of the constituent elements, the present disclosure is not limited to the shapes, directions, positional relationships and the like, except for the cases where they are specifically indicated as essential shapes, directions, positional relationships and the cases where they are limited to specific shapes, directions, positional relationships and the like in principle.

[0075] The variants are not limited to the above-mentioned examples. For example, as long as there is no technical contradiction, multiple variants can be combined with each other. In addition, as long as there is no technical contradiction, all or part of the above-mentioned embodiments and all or part of the variants can be combined with each other.

[0076] (Public content)

[0077] As is apparent from the above description, the present disclosure includes at least the following viewpoints.

[0078] <Viewpoint 1-1>

[0079] A communication control device (50) configured to control communication between a central unit (2) as a master device and a sensor unit (3) as a slave device in a sensor system (1) including the central unit (2) as a master device and the sensor unit (3) as a slave device, comprises:

[0080] A sensitivity acquisition unit (51) for acquiring whether the setting state of the sensitivity in the detection operation of the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0081] A communication control unit (52) communicates a special communication signal, which is a communication signal that is a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

[0082] <Viewpoint 1-2>

[0083] In viewpoint 1-1, the sensitivity is set to change as time passes during the detection operation.

[0084] <Viewpoints 1-3>

[0085] In aspect 1-1 or 1-2, the special communication signal includes a command signal transmitted from the central unit to the sensor unit, and a response signal transmitted from the sensor unit to the central unit in response to the command signal.

[0086] <Viewpoints 1-4>

[0087] In any one of aspects 1-1 to 1-3, the communication control unit communicates a non-special communication signal different from the special communication signal in the high-sensitivity state.

[0088] <Viewpoints 1-5>

[0089] In Views 1-4,

[0090] The above-mentioned sensor system is constructed to add serial symbols to the above-mentioned non-special communication signal in sequence according to the time sequence of sending and receiving, and reset the above-mentioned symbol to be added next time to the initial value by sending and receiving the reset signal of the above-mentioned special communication signal. On the other hand, even if the above-mentioned special communication signal different from the above-mentioned reset signal is sent and received, the resetting of the above-mentioned symbol to the above-mentioned initial value is prohibited.

[0091] <Viewpoints 1-6>

[0092] In aspect 1-4 or 1-5, the non-special communication signal includes a detection result signal corresponding to a result of the detection operation of the sensor unit.

[0093] <Viewpoints 1-7>

[0094] In any of the viewpoints 1-4 to 1-6,

[0095] The sensor system is configured to be switchable between a first communication mode in which bidirectional communication is performed between the central unit and the sensor unit, and a second communication mode in which unidirectional communication is performed from the sensor unit to the central unit when the sensor unit receives a trigger signal from the central unit.

[0096] The special communication signal is a communication signal sent and received via the first communication mode.

[0097] The non-special communication signal is a communication signal sent and received via the second communication mode.

[0098] <Viewpoints 1-8>

[0099] In Views 1-7,

[0100] The first communication mode is the command response mode in the DSI protocol.

[0101] The second communication mode is a periodic data collection mode in the DSI protocol.

[0102] <Viewpoints 1-9>

[0103] In viewpoint 1-7 or 1-8, the communication mode is changed from the first communication mode to the second communication mode when there is a mode change signal for changing the communication mode from the first communication mode to the second communication mode, a detection start signal for starting the detection action in the sensor unit, or a detection condition setting signal for setting the condition of the detection action in the sensor unit, which is the special communication signal.

[0104] <Viewpoints 1-10>

[0105] In any one of aspects 1-7 to 1-9, when the special communication signal is received in the second communication mode, a process corresponding to the received special communication signal is executed.

[0106] <Viewpoints 1-11>

[0107] In any one of aspects 1-1 to 1-10, the sensor unit is an object detection sensor that receives a reflected wave of the detection wave reflected by the object (B).

[0108] <Viewpoints 1-12>

[0109] In aspect 1-11, the sensor unit is mounted on a vehicle (C) to detect the object existing around the vehicle.

[0110] <Viewpoint 2-1>

[0111] A communication control method for controlling communication between a central unit (2) as a host device and a sensor unit (3) as a slave device in a sensor system (1) comprising:

[0112] a sensitivity acquisition process for acquiring whether the setting state of the sensitivity in the detection operation in the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0113] The communication control process communicates the special communication signal, which is a communication signal that becomes a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

[0114] <Viewpoint 2-2>

[0115] In viewpoint 2-1, the sensitivity is set to change as time passes during the detection operation.

[0116] <Viewpoint 2-3>

[0117] In aspect 2-1 or 2-2, the special communication signal includes a command signal transmitted from the central unit to the sensor unit, and a response signal transmitted from the sensor unit to the central unit in response to the command signal.

[0118] <Viewpoints 2-4>

[0119] In any one of aspects 2-1 to 2-3, the communication control process communicates a non-special communication signal different from the special communication signal in the high-sensitivity state.

[0120] <Viewpoints 2-5>

[0121] In Viewpoints 2-4,

[0122] The above-mentioned sensor system is constructed to add serial symbols to the above-mentioned non-special communication signal in sequence according to the time sequence of sending and receiving, and reset the above-mentioned symbol to be added next time to the initial value by sending and receiving the reset signal of the above-mentioned special communication signal. On the other hand, even if the above-mentioned special communication signal different from the above-mentioned reset signal is sent and received, the resetting of the above-mentioned symbol to the above-mentioned initial value is prohibited.

[0123] <Viewpoint 2-6>

[0124] In aspect 2-4 or 2-5, the non-special communication signal includes a detection result signal corresponding to a result of the detection operation of the sensor unit.

[0125] <Viewpoint 2-7>

[0126] In any of the viewpoints 2-4 to 2-6,

[0127] The sensor system is configured to be switchable between a first communication mode in which bidirectional communication is performed between the central unit and the sensor unit, and a second communication mode in which unidirectional communication is performed from the sensor unit to the central unit when the sensor unit receives a trigger signal from the central unit.

[0128] The special communication signal is a communication signal sent and received via the first communication mode.

[0129] The non-special communication signal is a communication signal sent and received via the second communication mode.

[0130] <Viewpoint 2-8>

[0131] In Viewpoints 2-7,

[0132] The first communication mode is the command response mode in the DSI protocol.

[0133] The second communication mode is a periodic data collection mode in the DSI protocol.

[0134] <Viewpoint 2-9>

[0135] In viewpoint 2-7 or 2-8, the communication mode is changed from the first communication mode to the second communication mode when there is sent or received a mode change signal as the special communication signal for changing the communication mode from the first communication mode to the second communication mode, a detection start signal for starting the detection action in the sensor unit, or a detection condition setting signal for setting the condition of the detection action in the sensor unit.

[0136] <Viewpoint 2-10>

[0137] In any one of aspects 2-7 to 2-9, when the special communication signal is received in the second communication mode, a process corresponding to the received special communication signal is executed.

[0138] <Viewpoint 2-11>

[0139] In any one of aspects 2-1 to 2-10, the sensor unit is an object detection sensor that receives a reflected wave of the detection wave reflected by the object (B).

[0140] <Viewpoint 2-12>

[0141] In aspect 2-11, the sensor unit is mounted on a vehicle (C) to detect the object existing around the vehicle.

[0142] <Viewpoint 3-1>

[0143] In a communication control program executed by a communication control device (50) configured to control communication between a central unit (2) as a master device and a sensor unit (3) as a slave device and the sensor unit in a sensor system (1),

[0144] The processing performed by the communication control device includes:

[0145] a sensitivity acquisition process for acquiring whether the setting state of the sensitivity in the detection operation in the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and

[0146] The communication control process communicates the special communication signal, which is a communication signal that becomes a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

[0147] <Viewpoint 3-2>

[0148] In viewpoint 3-1, the sensitivity is set to change as time passes during the detection operation.

[0149] <Viewpoint 3-3>

[0150] In aspect 3-1 or 3-2, the special communication signal includes a command signal transmitted from the central unit to the sensor unit, and a response signal transmitted from the sensor unit to the central unit in response to the command signal.

[0151] <Viewpoint 3-4>

[0152] In any one of aspects 3-1 to 3-3, the communication control process communicates a non-special communication signal different from the special communication signal in the high-sensitivity state.

[0153] <Viewpoints 3-5>

[0154] In view 3-4,

[0155] The above-mentioned sensor system is constructed to add serial symbols to the above-mentioned non-special communication signal in sequence according to the time sequence of sending and receiving, and reset the above-mentioned symbol to be added next time to the initial value by sending and receiving the reset signal of the above-mentioned special communication signal. On the other hand, even if the above-mentioned special communication signal different from the above-mentioned reset signal is sent and received, the resetting of the above-mentioned symbol to the above-mentioned initial value is prohibited.

[0156] <Viewpoints 3-6>

[0157] In aspect 3-4 or 3-5, the non-special communication signal includes a detection result signal corresponding to a result of the detection operation of the sensor unit.

[0158] <Viewpoints 3-7>

[0159] In any of Viewpoints 3-4 to 3-6,

[0160] The sensor system is configured to be switchable between a first communication mode in which bidirectional communication is performed between the central unit and the sensor unit, and a second communication mode in which unidirectional communication is performed from the sensor unit to the central unit when the sensor unit receives a trigger signal from the central unit.

[0161] The special communication signal is a communication signal sent and received via the first communication mode.

[0162] The non-special communication signal is a communication signal sent and received via the second communication mode.

[0163] <Viewpoints 3-8>

[0164] In Views 3-7,

[0165] The first communication mode is the command response mode in the DSI protocol.

[0166] The second communication mode is a periodic data collection mode in the DSI protocol.

[0167] <Viewpoints 3-9>

[0168] In viewpoint 3-7 or 3-8, the communication mode is changed from the first communication mode to the second communication mode when there is sent or received a mode change signal as the special communication signal for changing the communication mode from the first communication mode to the second communication mode, a detection start signal for starting the detection action in the sensor unit, or a detection condition setting signal for setting the condition of the detection action in the sensor unit.

[0169] <Viewpoint 3-10>

[0170] In any one of aspects 3-7 to 3-9, when the special communication signal is received in the second communication mode, a process corresponding to the received special communication signal is executed.

[0171] <Viewpoint 3-11>

[0172] In any one of aspects 3-1 to 3-10, the sensor unit is an object detection sensor that receives a reflected wave of the detection wave reflected by the object (B).

[0173] <Viewpoint 3-12>

[0174] In aspect 3-11, the sensor unit is mounted on a vehicle (C) to detect the object existing around the vehicle.

Claims

1. A communication control device, comprising: a communication control device (50) configured to control communication between a central unit (2) as a master device and a sensor unit (3) as a slave device in a sensor system (1), wherein: have: A sensitivity acquisition unit (51) for acquiring whether the setting state of the sensitivity in the detection operation of the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and A communication control unit (52) communicates a special communication signal, which is a communication signal that is a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

2. The communication control device according to claim 1, wherein: The sensitivity is set to change as time passes during the detection operation.

3. The communication control device according to claim 1, wherein: The special communication signal includes a command signal sent from the central unit to the sensor unit and a response signal sent from the sensor unit to the central unit in response to the command signal.

4. The communication control device according to claim 1, wherein: The communication control unit communicates a non-special communication signal different from the special communication signal in the high-sensitivity state.

5. The communication control device according to claim 4, wherein: The above-mentioned sensor system is constructed to add serial symbols to the above-mentioned non-special communication signal in sequence according to the time sequence of sending and receiving, and reset the above-mentioned symbol to be added next time to the initial value by sending and receiving the reset signal of the above-mentioned special communication signal. On the other hand, even if the above-mentioned special communication signal different from the above-mentioned reset signal is sent and received, the resetting of the above-mentioned symbol to the above-mentioned initial value is prohibited.

6. The communication control device according to claim 4, wherein: The non-special communication signal includes a detection result signal corresponding to a result of the detection operation of the sensor unit.

7. The communication control device according to claim 4, wherein: The sensor system is configured to be switchable between a first communication mode and a second communication mode, wherein the first communication mode enables bidirectional communication between the central unit and the sensor unit, and the second communication mode enables unidirectional communication from the sensor unit to the central unit when the sensor unit receives a trigger signal from the central unit. The special communication signal is a communication signal sent and received via the first communication mode. The non-special communication signal is a communication signal sent and received via the second communication mode.

8. The communication control device according to claim 7, wherein: The first communication mode is the command response mode in the DSI protocol. The second communication mode is a periodic data collection mode in the DSI protocol.

9. The communication control device according to claim 7, wherein: The communication mode is changed from the first communication mode to the second communication mode when a mode change signal serving as the special communication signal is sent or received, which is used to change the communication mode from the first communication mode to the second communication mode, a detection start signal for starting the detection action in the sensor unit, or a detection condition setting signal for setting the condition of the detection action in the sensor unit.

10. The communication control device according to claim 7, wherein: When the special communication signal is received in the second communication mode, a process corresponding to the received special communication signal is executed.

11. The communication control device according to claim 1, wherein: The sensor unit is an object detection sensor that receives a reflected wave resulting from the detection wave being reflected by the object (B).

12. The communication control device according to claim 11, wherein: The sensor unit is mounted on a vehicle (C) to detect the object existing around the vehicle.

13. A communication control method for controlling communication between a central unit (2) as a host device and a sensor unit (3) as a slave device in a sensor system (1), wherein: obtaining whether the setting state of the sensitivity in the detection operation of the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state, The special communication signal, which is a communication signal that is a noise source in the detection operation, is communicated in the low-sensitivity state instead of the high-sensitivity state.

14. A communication control program executed by a communication control device (50) configured to control communication between a central unit (2) as a master device and a sensor unit (3) as a slave device in a sensor system (1) comprising the central unit (2) as a master device and the sensor unit (3) as a slave device, wherein: The processing performed by the communication control device includes: a sensitivity acquisition process for acquiring whether the setting state of the sensitivity in the detection operation in the sensor unit is a predetermined high sensitivity state or a low sensitivity state lower than the high sensitivity state; and The communication control process communicates the special communication signal, which is a communication signal that becomes a noise source in the detection operation, in the low sensitivity state instead of the high sensitivity state.

Images