JP7592510B2 - COMMUNICATION DEVICE AND COMMUNICATION METHOD - Google Patents

Description

The present invention relates to a communication device and a communication method.

Conventionally, there are many types of systems that are connected to devices such as sensors via wireless communication, and various communication devices that transmit and receive signals to and from the devices used in the systems have been proposed (see, for example, Patent Document 1).

JP 2005-346612 A

In the above-mentioned communication device, for example, connected devices may be replaced due to changes in system design, specifications, or function additions. However, in the communication device according to the conventional technology, there is room for improvement in terms of communicating at an appropriate timing according to the currently connected device after a device is replaced.

The present invention has been made in consideration of the above, and aims to provide a communication device and a communication method that can communicate at appropriate timing according to the connected device.

In order to solve the above problems and achieve the object, the present invention provides a communication device connected to multiple devices via wireless communication, comprising an acquisition unit and a determination unit. The acquisition unit acquires communication information related to communication between the multiple devices. The determination unit determines a communication schedule between the multiple devices and the communication device based on the communication information acquired by the acquisition unit.

According to the present invention, communication can be performed at appropriate timing according to the connected device.

FIG. 1 is a diagram showing an overview of a communication method according to an embodiment. FIG. 2 is a block diagram illustrating an example of the configuration of a vehicle control system including a communication device according to the embodiment. FIG. 3 is a block diagram showing an example of the configuration of the parent device (communication device). FIG. 4 is a diagram illustrating an example of communication information. FIG. 5 is a diagram for explaining the process of determining a communication schedule. FIG. 6 is a flowchart showing a processing procedure executed by the parent device (communication device). FIG. 7 is a block diagram showing an example of the configuration of a vehicle control system including a master unit (communication device) according to a modified example.

Embodiments of the communication device and communication method disclosed in the present application will be described in detail below with reference to the attached drawings. Note that the present invention is not limited to the embodiments described below.

<Communication method overview>
First, an overview of a communication method by a communication device according to an embodiment will be described below with reference to Fig. 1. Fig. 1 is a diagram showing an overview of the communication method according to an embodiment.

The communication method according to the embodiment is executed by, for example, a communication device 50 provided in a vehicle control system 1. Specifically, as shown in FIG. 1, the vehicle control system 1 includes a main unit 10, a specific device 20, and a sub-unit 30, and is mounted on a vehicle (not shown). Note that, although the above description states that a system including the main unit 10 and the like (here, the vehicle control system 1) is mounted on a vehicle, this is not limiting, and the system may be mounted on, for example, other types of devices that perform communication processing.

The main unit 10 includes a control device 40 and a communication device 50. The sub-unit 30 includes a device 100 and a wireless communication device 200.

A specific device 20 and a sub-unit 30 are communicatively connected to the main unit 10, and the main unit 10 controls the specific device 20 and the device 100 of the sub-unit 30.

For example, the main unit 10 is connected to a specific device 20 via wired communication. The specific device 20 is, for example, a device that has basic functions in a vehicle (in other words, essential functions). For example, the specific device 20 is a drive source such as an engine or a motor, vehicle control devices such as brakes, body system devices such as air conditioners, seats, door locks, and safety system devices such as airbags and seat belts, but these are merely examples and are not limited thereto. There are also system examples in which all or part of these devices are arranged in sub-units.

The control device 40 of the main unit 10 has a microcomputer equipped with, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and can control a specific device 20.

The communication device 50 of the main unit 10 is connected to the multiple devices 100 via wireless communication. For example, the communication device 50 is connected to be able to communicate with the multiple devices 100 via the wireless communication device 200 of the sub-unit 30. Note that while FIG. 1 shows an example in which there are three devices 100, this is not limiting and there may be two devices, or four or more devices.

The communication device 50 can function as a parent device (master device) having, for example, an ECU (Electronic Control Unit), and the wireless communication device 200 of the device 100 can function as a child device (slave device). Note that the communication device 50 and the device 100 may be indirectly connected via a relay device such as the wireless communication device 200, or may be directly connected as shown in FIG. 7 described later.

The communication device 50 can control communication with the device 100 by transmitting and receiving various signals to and from the device 100 via the wireless communication device 200. The device 100 is, for example, various sensors and various actuators mounted on a vehicle. The sensors and actuators that are the device 100 are used, for example, to control the vehicle, but are not limited to this.

Incidentally, the device 100 connected to the communication device 50 may be replaced or newly installed due to, for example, design changes, specification changes, or additional functions of the vehicle control system 1. Since the communication device 50 and the device 100 are connected via wireless communication, workers can easily replace or install the device 100 compared to wired communication.

The amount of communication with the communication device 50 and the communication control period of the device 100 differ depending on the type of device 100. Therefore, when the device 100 is replaced, the amount of communication with the communication device 50 and the communication control period of the device 100 may change, and there is a risk that communication cannot be performed at an appropriate timing according to the device 100.

Therefore, in the communication device 50 according to this embodiment, even if the device 100 is replaced, communication can be performed at an appropriate timing according to the connected device 100.

Specifically, the communication device 50 acquires communication information related to communication among the multiple devices 100 (step S1). More specifically, the communication device 50 acquires communication information among the multiple devices 100 at a predetermined timing. Note that the predetermined timing is, for example, the timing when the main unit 10 including the communication device 50 is powered on, but is not limited to this.

The communication information also includes, but is not limited to, the communication volume of each of the multiple devices 100 and the communication control period of each of the multiple devices 100. In other words, the communication information may include either the communication volume or the communication control period, or may include information related to other communications.

Next, the communication device 50 determines a communication schedule between the multiple devices 100 and the communication device 50 based on the acquired communication information (step S2). Details of determining the communication schedule will be described later.

In this way, the communication device 50 according to this embodiment acquires communication information from multiple devices 100 and determines a communication schedule based on the acquired communication information, so the communication schedule can be adapted to the currently connected device 100. Therefore, by using this communication schedule, the communication device 50 can communicate at appropriate timing according to the connected device 100.

<Vehicle control system including communication device>
Next, the configuration of the vehicle control system 1 including the communication device 50 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the configuration of the vehicle control system 1 including the communication device 50 according to the embodiment. Note that, hereinafter, the communication device 50 may be referred to as the "parent device 50" and the wireless communication device 200 may be referred to as the "child device 200".

As shown in FIG. 2, the vehicle control system 1 includes a main unit 10 and a sub-unit 30. The main unit 10 includes the control device 40 and a parent unit (communication device) 50. The sub-unit 30 includes a child unit (wireless communication device) 200 and a device 100.

The communication device 50 is connected to the child device 200 of the subunit 30 via wireless communication. In FIG. 2, an example is shown in which there are two subunits 30 and two child devices 200, but there may be one or three or more. In the following, one of the two subunits 30 may be referred to as "subunit 30a" and the other as "subunit 30b", and when there is no particular distinction between them, they will be referred to as "subunit 30". In the following, the child device 200 on the subunit 30a side may be referred to as "child device 200a" and the child device 200 on the subunit 30b side may be referred to as "child device 200b", and when there is no particular distinction between them, they will be referred to as "child device 200".

In the subunit 30, a plurality of devices 100 are connected to the child device 200 so as to be able to communicate with each other. Note that the child device 200 and the devices 100 are connected via wired communication, but are not limited to this and may be connected via wireless communication.

The child device 200 functions as a relay device having a microcomputer equipped with, for example, a CPU, ROM, RAM, etc. For example, the child device 200 can receive signals and information transmitted from the parent device 50 and transmit them to each of the multiple devices 100 connected to it. Also, for example, the child device 200 can receive signals and information transmitted from each of the multiple devices 100 connected to it and transmit them to the parent device 50. In other words, the device 100 communicates with the parent device 50 via the child device 200.

As described above, there are a plurality of devices 100. For ease of understanding, FIG. 2 shows an example in which two devices 100 are connected to child device 200a and two devices 100 are connected to child device 200b, but the number of devices 100 is not limited to the number shown in FIG. 2. In addition, hereinafter, one of the two devices 100 connected to child device 200a may be referred to as "device 100a1" and the other as "device 100a2". In addition, one of the two devices 100 connected to child device 200b may be referred to as "device 100b1" and the other as "device 100b2". In addition, when describing these without making any particular distinction, they will be referred to as "device 100".

In addition, in the vehicle control system 1 according to this embodiment, the devices 100 in the subunit 30 can be added (mounted) or removed (dismounted) at will, and the subunit 30 itself can also be added or removed at will. In other words, devices that are easily added, removed, or replaced, for example devices that the user can select to install or replace according to preference, are preferably set as devices 100 in the subunit 30.

<Parent unit (communication device)>
Next, the parent device 50 will be described with reference to Fig. 3 etc. Fig. 3 is a block diagram showing an example of the configuration of the parent device (communication device) 50. Note that in the block diagram of Fig. 3, only components necessary for explaining the features of this embodiment are shown as functional blocks, and descriptions of general components are omitted.

In other words, each component shown in the block diagram of FIG. 3 is a functional concept, and does not necessarily have to be physically configured as shown. For example, the specific form of distribution and integration of each functional block is not limited to that shown, and all or part of it can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

As shown in FIG. 3, the parent device 50 includes a communication unit 51, an output unit 52, a communication unit for a specific device 53, a control unit 60, and a memory unit 70.

The communication unit 51 is a communication interface that is connected to the child device 200 etc. so as to enable two-way communication, and transmits and receives signals and information between the child device 200 etc., for example.

The output unit 52 outputs various information, such as information indicating that the communication conditions between the parent unit 50 and the device 100 have not been met, as described below. For example, the output unit 52 includes a display unit such as a display, an audio output unit such as a speaker, a warning light, etc., and outputs various information to a user (for example, a worker who performs work such as replacing the device 100).

The communication unit for a specific device 53 is a communication interface that connects to a specific device 20 (see FIG. 1) or the like for two-way communication, and transmits and receives signals and information between the specific device 20 and the like, for example.

The control unit 60 includes an acquisition unit 61, a judgment unit 62, a decision unit 63, a notification unit 64, and a processing unit 65, and includes, for example, a computer having a CPU, ROM, RAM, input/output ports, etc., and various circuits.

The computer's CPU functions as the acquisition unit 61, judgment unit 62, decision unit 63, notification unit 64, and processing unit 65 of the control unit 60, for example, by reading and executing a program stored in the ROM.

In addition, at least some or all of the acquisition unit 61, judgment unit 62, decision unit 63, notification unit 64, and processing unit 65 of the control unit 60 can be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The storage unit 70 is configured with a storage device such as a non-volatile memory, a data flash, or a hard disk drive. The storage unit 70 stores communication information 71.

The communication information 71 is information related to communication in the device 100. Here, the communication information 71 will be described with reference to FIG. 4. FIG. 4 is a diagram showing an example of the communication information 71.

As shown in FIG. 4, communication information 71 includes items such as "child unit ID," "device ID," "communication volume," and "communication control period," and each item is associated with each other.

The "child unit ID" is identification information that identifies the child unit 200. In the example of FIG. 4, the child unit ID "Ca" is identification information that indicates the child unit 200a, and the child unit ID "Cb" is identification information that indicates the child unit 200b.

The "device ID" is identification information that identifies the device 100. In the example of FIG. 4, the device ID "Da1" is identification information that indicates the device 100a1, and the device ID "Da2" is identification information that indicates the device 100a2. Furthermore, the device ID "Db1" is identification information that indicates the device 100b1, and the device ID "Db2" is identification information that indicates the device 100b2.

"Communication volume" is information indicating the communication volume of device 100. In more detail, "communication volume" is information indicating the communication volume [bytes] that device 100 transmits and receives with parent device 50 in one communication (in other words, during one communication control period).

In the example of FIG. 4, the communication volume "Tra ₁ " is information indicating the communication volume of device 100a1, and the communication volume "Tra ₂ " is information indicating the communication volume of device 100a2. Furthermore, the communication volume "Trb ₁ " is information indicating the communication volume of device 100b1, and the communication volume "Trb ₂ " is information indicating the communication volume of device 100b2. Note that in the example shown in FIG. 4, for convenience, "communication volume" is abstractly described as "Tra ₁ ", but it is assumed that concrete information is stored in "Tra ₁ ". Below, other information may also be abstractly described.

The "communication control period" is information indicating the communication control period of the device 100. In more detail, the "communication control period" is information indicating the control period [ms] of the communication processing by the device 100, and more specifically, information indicating the time [ms] from when the device 100 starts the current communication processing until the communication processing is completed and the device 100 starts the next communication processing.

4, the communication control period " _Ta1 " is information indicating the communication control period of the device 100a1, and the communication control period " _Ta2 " is information indicating the communication control period of the device 100a2. Also, the communication control period " _Tb1 " is information indicating the communication control period of the device 100b1, and the communication control period " _Tb2 " is information indicating the communication control period of the device 100b2.

In this way, the communication information 71 includes information on the communication volume of each of the multiple devices 100 and the communication control period of each of the multiple devices 100. These communication volumes and communication control periods are set in advance for each device 100.

Returning to the explanation of FIG. 3, the acquisition unit 61 of the control unit 60 acquires communication information related to communication among the multiple devices 100. For example, the acquisition unit 61 acquires the communication information of the multiple devices 100 when a predetermined timing arrives. In detail, the acquisition unit 61 acquires the communication information of the multiple devices 100 each time the main unit 10 including the parent device 50 is turned on. The acquisition unit 61 registers the acquired information in the memory unit 70 as communication information 71.

Specifically, when the main unit 10 including the parent device 50 is powered on, the acquisition unit 61 can acquire communication information of the devices 100 via the child device 200 (see FIG. 2). That is, for example, each of the multiple devices 100 has its own communication information stored in advance in a memory unit, and when the main unit 10 including the parent device 50 is powered on, the child device 200 aggregates communication information from the multiple devices 100 connected thereto. Then, the acquisition unit 61 acquires the communication information aggregated from the devices 100 to the child device 200.

In this manner, in this embodiment, the communication information is configured to be collected and acquired in the child device 200. Therefore, even if the number of devices 100 increases and the amount of communication information increases, for example, the communication information of multiple devices 100 can be easily and reliably acquired.

When the vehicle is turned on and the main unit 10 including the parent unit 50 is energized, the acquisition unit 61 may acquire communication information each time the vehicle is turned on. In the above description, the acquisition unit 61 acquires communication information from the device 100 via the child unit 200, but this is not limited to this. That is, for example, the communication information of the device 100 may be registered in the memory unit of the child unit 200 or the memory unit 70 of the parent unit 50 by an external device such as a PC (Personal Computer), smartphone, or tablet terminal, and the acquisition unit 61 may acquire the communication information from such a memory unit.

The determination unit 62 determines whether the currently connected devices 100 and the parent device 50 can communicate normally. In detail, the determination unit 62 executes a process of determining whether a communication condition indicating a condition under which communication between the devices 100 and the parent device 50 is possible is satisfied.

To be more specific, as described above, in the parent unit 50, the device 100 may be replaced or a new device may be added. In such a case, if the communication conditions when the currently connected device 100 communicates with the parent unit 50 exceed the communication capabilities (specs) of the parent unit 50, there is a risk that normal communication will not be possible.

In this embodiment, a determination is made based on the communication information of the multiple devices 100 connected to the parent device 50 as to whether the communication situation when the multiple devices 100 communicate with the parent device 50 satisfies the condition that does not exceed the communication capacity of the parent device 50. In other words, in this embodiment, a determination is made as to whether the condition (communication condition) that allows communication between the multiple devices 100 and the parent device 50 is met.

This allows you to determine whether the device 100 connected to the parent unit 50 is appropriate for the parent unit 50's communication capabilities, etc.

The following is a more detailed explanation of the determination process by the determination unit 62. Prior to the determination process, the determination unit 62 calculates the following four values.
1. Calculation of the shortest communication control period Tmin among the communication control periods of the multiple devices 100.
2. Calculation of the total communication volume W indicating the total communication volume of the multiple devices 100.
3. Calculation of the required transmission speed S, which indicates the transmission speed required for communication in the case of the shortest communication control period.
4. Calculation of a communication completion time Tx required for all communications among the multiple devices 100 to be completed.

To explain each value in detail, the shortest communication control period Tmin is calculated by the following formula (1).
Tmin [ms] = min (Ta ₁ , Ta ₂ ,..., Tb ₁ , Tb ₂ ,...)
...Equation (1)

Specifically, the determination unit 62 reads the communication control periods of the multiple devices 100 from the communication information 71 in the memory unit 70, and calculates the shortest communication control period Tmin among the communication control periods of the multiple devices 100 using formula (1).

The total communication volume W is calculated by the following formula (2).
W[byte]=ΣTra _n +ΣTrb _n +... n=1, 2,...
...Equation (2)

Specifically, the determination unit 62 reads the communication volumes of the multiple devices 100 from the communication information 71 in the storage unit 70, and calculates the total communication volume W by adding up all the communication volumes of the multiple devices 100 using formula (2). That is, among the multiple devices 100, there are some types in which communication is performed intermittently. Here, the communication volume is calculated based on the assumption that communication is performed among all of the multiple devices 100, including such devices 100. In other words, the communication volume when the communication volume between the multiple devices 100 and the parent unit 50 is the highest, is calculated as the total communication volume W.

The required transmission speed S is calculated by the following formula (3).
S [bps] = W [byte] x 8 x 1000 / Tmin [ms] x any margin
...Equation (3)

Specifically, the determination unit 62 calculates the required transmission speed S required for communication between the multiple devices 100 and the parent device 50 in the case of the shortest communication control period Tmin based on the total communication volume W calculated by formula (2) and the shortest communication control period Tmin calculated by formula (1). Here, the required transmission speed S is calculated as the transmission speed required to complete communication of the total communication volume W of the multiple devices 100 during the shortest communication control period Tmin (in other words, from the time when the device 100 having the shortest communication control period starts the current communication process until the device 100 completes the communication process and starts the next communication process). In other words, the required transmission speed S is the transmission speed when it is assumed that the communication of the largest total communication volume W between the multiple devices 100 and the parent device 50 is completed within the shortest communication control period Tmin. Note that "8" and "1000" in formula (3) are values for converting [byte] or [ms] to [bps].

The communication completion time Tx is calculated by the following formula (4).
Communication completion time Tx [ms] = {( _ΣTran [bytes] x 8) / (WS [bps] / 1000) x any margin} + {( _ΣTrbn [bytes] x 8) / (WS [bps] / 1000) x any margin} + ... n = 1, 2, ...
...Equation (4)

"WS" in formula (4) indicates the transmission speed of the parent device 50 and indicates the communication capability of the parent device 50. The transmission speed WS of the parent device 50 is stored in advance in, for example, the memory unit 70 of the parent device 50.

Specifically, the determination unit 62 reads out the communication amounts and transmission speeds WS of the multiple devices 100 from the storage unit 70, and calculates the communication completion time Tx until all of the communication of the multiple devices 100 is completed using formula (4). Here, the time required to complete communication for each child device 200a, 200b when communicating at the actual transmission speed WS of the parent device 50 is calculated, and the calculated times are added together to calculate the communication completion time Tx. In detail, for example, the communication completion time Tx is calculated by adding together the communication amounts obtained by adding together all of the communication amounts of the devices 100a1, 100a2 connected to the child device 200a and the communication completion time Tx is calculated by adding together the communication amounts obtained by adding together all of the communication amounts of the devices 100b1, 100b2 connected to the child device 200b and the communication completion time Tx is calculated by adding together the communication amounts obtained by adding together all of the communication amounts of the devices 100b1, 100b2 connected to the child device 200b and the communication completion time Tx. That is, the communication completion time Tx is the time when it is assumed that the largest total communication volume W between the multiple devices 100 (child devices 200) and the parent device 50 is completed at the transmission speed WS. Note that "8" and "1000" in formula (4) are values for unit conversion.

Then, the judgment unit 62 executes a judgment process to judge whether or not the conditions (communication conditions) for communication between the multiple connected devices 100 and the parent unit 50 are met, using the shortest communication control period Tmin, the required transmission speed S, the communication completion time Tx, and the transmission speed WS of the parent unit 50 calculated as described above.

Specific communication conditions are shown in the following formulas (5) and (6). When both formulas (5) and (6) are satisfied, the determination unit 62 determines that communication between the multiple connected devices 100 and the parent device 50 is possible, in other words, that communication is possible normally.

WS[bps]>S[bps] ...Formula (5)
Tmin [ms] > Tx [ms] ...Formula (6)

Specifically, formula (5) is a communication condition indicating that the transmission speed WS, which indicates the communication capability of the parent device 50, is greater than the required transmission speed S required for communication in the case of the shortest communication control period Tmin. Here, the required transmission speed S is the transmission speed when it is assumed that the highest total communication volume W between the multiple devices 100 and the parent device 50 is completed in the shortest communication control period Tmin, as described above. Therefore, if the transmission speed WS of the parent device 50 is greater than this required transmission speed S, it can be determined that normal communication between the multiple devices 100 and the parent device 50 is possible even in the case of the highest total communication volume W.

In this way, the determination unit 62 calculates the total communication volume W and the shortest communication control period Tmin, calculates the required transmission speed S based on the calculated total communication volume W and the shortest communication control period Tmin, and performs the determination process based on the calculated required transmission speed S and the transmission speed WS of the parent unit 50.

This allows for accurate determination of whether the device 100 connected to the parent device 50 is appropriate for the parent device 50's transmission speed WS.

Next, equation (6) will be described. Equation (6) is a communication condition indicating that the shortest communication control period Tmin is longer than the communication completion time Tx. Here, the communication completion time Tx is the time when it is assumed that the communication of the largest total communication volume W between the multiple devices 100 (child devices 200) and the parent device 50 is completed at the transmission speed WS, as described above. Therefore, if the shortest communication control period Tmin is longer than this communication completion time Tx, the next communication process of the device 100 having the shortest communication control period Tmin will not arrive before the communication of the current communication process is completed for the largest total communication volume W, and therefore it can be determined that normal communication between the multiple devices 100 and the parent device 50 is possible.

In this way, the judgment unit 62 calculates the communication completion time Tx and the shortest communication control period Tmin, and executes the judgment process based on the calculated communication completion time Tx and the shortest communication control period Tmin.

This allows for accurate determination of whether the device 100 connected to the parent device 50 is appropriate for the device 100 having the shortest communication control period Tmin.

When both formula (5) and formula (6) are satisfied, the judgment unit 62 judges that communication between the multiple connected devices 100 and the parent device 50 is possible and the communication conditions are satisfied. On the other hand, when at least one of formula (5) and formula (6) is not satisfied, the judgment unit 62 judges that normal communication between the multiple connected devices 100 and the parent device 50 is not possible and the communication conditions are not satisfied. Then, the judgment unit 62 outputs information indicating the judgment result to the decision unit 63 and the notification unit 64.

The determination unit 63 can determine a communication schedule between the multiple devices 100 and the parent device 50 based on the communication information. In detail, the determination unit 63 determines the communication schedule based on the communication information acquired each time the power is turned on. As a result, in this embodiment, the communication schedule can be made appropriate for the currently connected device 100.

Here, the process of determining a communication schedule will be described with reference to FIG. 5. FIG. 5 is a diagram illustrating the process of determining a communication schedule.

5, a description will be given of values calculated in advance by the determination unit 63. The determination unit 63 calculates the following two values for each child device 200 prior to the process of determining the communication schedule.
1. Calculation of the shortest communication control periods Tamin and Tbmin among the communication control periods of the devices 100 connected to each child device 200.
2. Calculation of communication completion times Txa and Txb required for all communications to be completed in each child device 200.

To explain each value in more detail, the shortest communication control periods Tamin and Tbmin in each child device 200 are calculated by the following formula (7).
Tamin [ms] = min (Ta ₁ , Ta ₂ ,...)
Tbmin [ms] = min (Tb ₁ , Tb ₂ ,...)
...Equation (7)

Specifically, the determination unit 63 reads the communication control periods of the multiple devices 100 from the communication information 71 in the memory unit 70, and calculates the shortest communication control period Tamin, Tbmin for each child device 200, among the communication control periods of the multiple devices 100 connected to each child device 200, using formula (7).

The communication completion times Txa and Txb in each child device 200 are calculated by the following formula (8).
Communication completion time Txa [ms] = {( _ΣTran [bytes] x 8) / (WS [bps] / 1000) x any margin} n = 1, 2, ...
Communication completion time Txb [ms] = {(ΣTrb _n [byte] × 8) / (WS [bps] / 1000) × arbitrary margin} n = 1, 2,...
...Equation (8)

Specifically, the determination unit 63 reads out the communication volume and transmission speed WS of the multiple devices 100 from the storage unit 70, and calculates the communication completion times Txa, Txb required for all communication of the multiple devices 100 connected to each child device 200 to be completed using formula (8). Here, the time required for communication completion for each child device 200a, 200b when communication is performed at the actual transmission speed WS of the parent device 50 is calculated. Note that "8" and "1000" in formula (8) are values for unit conversion.

Then, the determination unit 63 determines (sets) the communication schedule using the shortest communication control periods Tamin, Tbmin and the communication completion times Txa, Txb calculated as above. For example, as shown in FIG. 5, the determination unit 63 starts communication control of the child device 200a when the shortest communication control period Tamin corresponding to the child device 200a has elapsed since the start of communication control and time t1 has arrived. That is, the determination unit 63 determines the communication schedule so that the devices 100a1, 100a2 connected to the child device 200a and the parent device 50 start communication. Then, when the communication completion time Txa for the child device 200a has elapsed from time t1, the communication of the devices 100a1, 100a2 connected to the child device 200a is completed (see time t2).

The decision unit 63 also starts communication control of the child device 200b when the communication between the devices 100a1 and 100a2 is completed and the shortest communication control period Tbmin corresponding to the child device 200b has elapsed since the start of communication control, reaching time t3. That is, the decision unit 63 decides a communication schedule so that the parent device 50 and the devices 100b1 and 100b2 connected to the child device 200b start communication. Then, when the communication completion time Txb for the child device 200b has elapsed from time t3, the communication between the devices 100b1 and 100b2 connected to the child device 200b is completed (see time t4).

The determination unit 63 also determines a communication schedule for starting the next communication control of the child device 200a at time t5 when the shortest communication control period Tamin has elapsed since time t1 when communication between the devices 100a1 and 100a2 connected to the child device 200a is started. Similarly, the determination unit 63 determines a communication schedule for starting the next communication control of the child device 200b at time t6 when the shortest communication control period Tbmin has elapsed since time t3 when communication between the devices 100b1 and 100b2 connected to the child device 200b is started.

In this way, the determination unit 63 according to this embodiment determines the communication schedule based on the communication volume and communication control period of the device 100. In detail, the determination unit 63 determines the communication schedule based on the communication volume and communication control period of the device 100, the shortest communication control periods Tamin and Tbmin, and the communication completion times Txa and Txb, which are calculated based on equations (7) and (8). This makes it possible to make the communication schedule more appropriate for the currently connected device 100.

Note that FIG. 5 shows an example in which the communication processing in child device 200a and the communication processing in child device 200b are shifted and do not overlap, but if the communication processing in each child device 200a and 200b overlaps, for example, a communication schedule may be determined in which one of the communication processes is performed according to a predetermined condition that is set in advance.

As one example, a priority may be set in advance for each child device 200a, 200b, and in the event of overlapping communication processes, a communication schedule may be determined such that the communication process with the higher priority is performed first. As another example, a communication schedule may be determined according to the order in which communication is started. In detail, in the event of overlapping communication processes, a communication schedule may be determined such that the communication process that was started first is completed before another overlapping communication process is performed.

The determination unit 63 may determine a communication schedule when the judgment unit 62 judges that the above-mentioned communication conditions are satisfied. Conversely, the determination unit 63 may not determine (set) a communication schedule when the judgment unit 62 judges that the communication conditions are not satisfied, that is, may prohibit the determination of a communication schedule.

Thereby, the determination unit 63 can determine a communication schedule only when, for example, the multiple connected devices 100 and the parent unit 50 can communicate normally. In other words, the determination unit 63 can avoid an increase in the processing load by performing unnecessary determination processing, such as determining a communication schedule, when, for example, there is a risk that the multiple connected devices 100 and the parent unit 50 cannot communicate normally.

Continuing with the explanation of FIG. 3, the notification unit 64 can notify the result of the determination process by the determination unit 62. For example, when the determination unit 62 determines that the communication conditions are not met, the notification unit 64 can notify information indicating that the communication conditions are not met.

Specifically, the notification unit 64 notifies a user (e.g., a worker who performs work such as replacing the device 100) of information indicating that the communication conditions have not been met via the output unit 52. As one example, the notification unit 64 notifies the user by displaying the information indicating that the communication conditions have not been met on the display unit, which is the output unit 52, outputting the information from the audio output unit, or turning on a warning light.

In this embodiment, for example, it is possible to make the user aware that there is a risk that the device 100 currently connected to the parent device 50 may not be able to communicate normally. Therefore, the user can take appropriate measures, such as replacing the connected device 100 with another device 100 or removing the device 100.

The process of determining whether the above-mentioned communication conditions are met and the process of determining the communication schedule can be performed using various methods, such as calculating the optimal solution using a genetic algorithm, but is not limited to these.

The processing unit 65 performs various processes for the control device 40 of the main unit 10 (see Figs. 1 and 2) and the specific device 20 (see Fig. 1) connected to the main unit 10. For example, in response to a request from the control device 40 or the specific device 20, the processing unit 65 performs a process of transmitting output data of the device 100 via the specific device communication unit 53 to the specific device 20 that performs cooperative control with the device 100 on the sub-unit 30 side.

<Control process of parent device (communication device) according to the embodiment>
Next, a specific processing procedure in the master unit (communication device) 50 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the processing procedure executed by the master unit (communication device) 50.

As shown in FIG. 6, the parent device 50 determines whether a predetermined timing has arrived (step S10). Here, the predetermined timing is, for example, the timing when the main unit 10 including the parent device 50 is turned on, so step S10 can also be said to be a process of determining whether the main unit 10 has been turned on.

When the parent unit 50 determines that the specified timing has not arrived (step S10, No), it skips the subsequent processing. On the other hand, when the parent unit 50 determines that the specified timing has arrived (step S10, Yes), i.e., when the main unit 10 is powered on, it acquires communication information regarding communication among the multiple devices 100 (step S11). In this way, the parent unit 50 acquires communication information of the multiple devices 100 every time the power is turned on.

Next, the parent unit 50 determines whether or not a communication condition indicating a condition under which communication between the multiple devices 100 and the parent unit 50 is possible is satisfied based on the acquired communication information (step S12). If the parent unit 50 determines that the communication condition is satisfied (step S12, Yes), it determines a communication schedule between the multiple devices 100 and the parent unit 50 based on the acquired communication information (step S13).

On the other hand, if the parent device 50 determines that the communication conditions are not met (step S12, No), it performs a process of notifying information indicating that the communication conditions are not met (step S14).

In the above, the predetermined timing is set to the timing when the main unit 10 is powered on, but this is not limited to this. That is, for example, the predetermined timing can be set arbitrarily, such as the timing when the device 100 is replaced with the parent unit 50, newly attached and connected, or removed (disconnected), or at a predetermined interval. Note that the device 100 added after powering on is, for example, an audio or visual device, or other device that does not affect safety when connected after powering on, but is not limited to this.

As described above, the parent unit (communication device) 50 according to the embodiment is connected to the multiple devices 100 via wireless communication. The parent unit 50 includes an acquisition unit 61 and a determination unit 63. The acquisition unit 61 acquires communication information related to communication among the multiple devices 100. The determination unit 63 determines a communication schedule between the multiple devices 100 and the parent unit 50 based on the communication information acquired by the acquisition unit 61. This allows communication to be performed at an appropriate timing according to the connected device.

<Modification>
Next, the configuration of a vehicle control system 1 including a parent unit (communication device) 50 according to a modified example will be described with reference to Fig. 7. Fig. 7 is a block diagram showing a configuration example of a vehicle control system 1 including a parent unit (communication device) 50 according to a modified example. Note that, in the following, components common to the embodiment will be denoted by the same reference numerals and description thereof will be omitted.

In the vehicle control system 1 according to the modified example, the parent device 50 of the main unit 10 and the device 100 of the sub-unit 30 are directly connected via wireless communication. That is, the parent device 50 and the device 100 are connected so as to be able to communicate with each other without going through the child device 200 of the embodiment.

As in the embodiment, the parent device 50 in the modified example acquires communication information of the multiple devices 100 when a predetermined timing arrives, such as when the main unit 10 including the parent device 50 is powered on, and determines a communication schedule based on the acquired communication information. This makes it possible to obtain the same effect as the embodiment.

The device 100 according to the modified example may be, for example, a control device having an ECU or the like. The above-described embodiments and modified examples may be combined as appropriate. That is, some of the multiple devices 100 may be connected to the parent device 50 via the child device 200, and the other devices 100 may be connected without the child device 200.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof.

1 Vehicle control system 50 Communication device (parent device)
61 acquisition unit 62 determination unit 63 determination unit 64 notification unit 100 device

Claims (8)

A communication device having a control unit and connected to a plurality of devices via wireless communication,
The control unit is
Acquire information on the communication volume and communication control period of each of the plurality of devices ;
calculating a required transmission rate indicating a transmission rate required for communication between the plurality of devices and the communication device based on a total communication volume in the plurality of devices calculated from the communication volume and the shortest communication control period among the communication control periods;
determining that communication with the plurality of devices is normally performed when the transmission speed of the communication device is higher than the required transmission speed, and determining a communication schedule with the plurality of devices ;
Communications equipment. The control unit is
if the transmission speed of the communication device is equal to or lower than the required transmission speed, it is determined that there is a risk that normal communication will not be possible, and a user is notified of the determination result.
The communication device according to claim 1 . A communication device having a control unit and connected to a plurality of devices via wireless communication,
The control unit is
Acquire information on the communication volume and communication control period of each of the plurality of devices ;
calculating a communication completion time required for communication with the plurality of devices to be completed based on a total communication volume in the plurality of devices calculated from the communication volume and a transmission speed of the communication device;
determining that the communication with the plurality of devices is normally performed when the communication completion time is shorter than the shortest communication control period among the communication control periods, and determining a communication schedule with the plurality of devices ;
Communications equipment. The control unit is
If the communication completion time is equal to or longer than the shortest communication control period, it is determined that there is a risk that normal communication will not be possible, and a user is notified of the determination result.
The communication device according to claim 3 . the plurality of devices are connected to a relay device,
The control unit is
acquiring, from the relay device, information on the communication volume and the communication control period aggregated from the plurality of devices to the relay device;
A communication device according to any one of claims 1 to 4 . the plurality of devices are connected to a plurality of relay devices,
The control unit is
determining the communication schedule based on the priorities set for the plurality of relay devices;
The communication device according to claim 5. A communication method performed by a communication device connected to a plurality of devices via wireless communication, comprising:
Acquire information on the communication volume and communication control period of each of the plurality of devices ;
calculating a required transmission rate indicating a transmission rate required for communication between the plurality of devices and the communication device based on a total communication volume in the plurality of devices calculated from the communication volume and the shortest communication control period among the communication control periods;
determining that communication with the plurality of devices is normally performed when the transmission speed of the communication device is higher than the required transmission speed, and determining a communication schedule with the plurality of devices ;
Communication methods. A communication method performed by a communication device connected to a plurality of devices via wireless communication, comprising:
Acquire information on the communication volume and communication control period of each of the plurality of devices ;
calculating a communication completion time required for communication with the plurality of devices to be completed based on a total communication volume in the plurality of devices calculated from the communication volume and a transmission speed of the communication device;
determining that the communication with the plurality of devices is normally performed when the communication completion time is shorter than the shortest communication control period among the communication control periods, and determining a communication schedule with the plurality of devices ;
Communication methods.

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