JP7456184B2 - Wireless power supply system - Google Patents

Description

The present invention relates to a wireless power supply system.

Wireless sensor systems are sometimes used in factories and the like. In the wireless sensor system, each sensor is not powered by wires, so each sensor is powered by wireless power supply or a battery.

In battery-powered sensors, intermittent operation of the sensor is realized to reduce battery consumption. Even in wirelessly powered sensors, the period during which power is supplied is limited (because the amount of power that is supplied is limited), so intermittent operation may be required to reduce power consumption. Although it is not a wireless sensor system, Patent Document 1 discloses a wireless power supply system that performs intermittent operation in order to suppress power consumption.

JP 2019-47729 Publication

For sensors that perform intermittent operation, the operation timing and operation cycle of the sensor are determined by parameters set inside the sensor. For this reason, devices (high-level devices) and systems (high-level systems) that use sensing data from sensors cannot control the operation timing of the sensors and cannot acquire sensing data at desired timings. For this reason, the current situation is that the application of sensors that perform intermittent operation is limited to applications where the timing of sensor operation is not important.

Another possible solution may be to narrow the sensing interval in the sensor, increase the number of times of sensing, and transmit sensing data for multiple times from the sensor to the host device or system. In this case, the higher-level device or system can extract and use data at a desired timing from among the plurality of received sensing data. However, with this solution, the number of sensing times in the sensor increases more than necessary, which increases power consumption and reduces the effectiveness of intermittent operation.

Moreover, when a plurality of sensors exist in a wireless sensor system, unless the communication timing of each sensor is controlled, the communications of the plurality of sensors may interfere with each other. If communication interference occurs, multiple transmissions must be made until communication is successful, further increasing power consumption.

The present invention has been made in view of the above-mentioned problems, and is a wireless device that can reduce power consumption by intermittent operation of a handset that receives wireless power supply, and also enables operation timing control from a base unit to a handset. The purpose is to provide a power supply system.

In order to solve the above problems, the wireless power supply system of the present invention is a wireless power supply system that wirelessly supplies power from a parent device to a slave device, wherein the slave device controls the operation of the slave device. a handset control unit that can take an operating state and a sleep state for intermittent operation; and a handset controller that detects a synchronization start command from the parent unit when the handset controller is in the sleep state; A synchronization start command detection unit starts the slave device control unit based on the synchronization start command, and an operation timing is set based on the synchronization command transmitted from the base unit, and the synchronization start command detecting unit starts the slave unit control unit based on the synchronization start command. and an operation timing control timer that outputs an operation trigger to a slave unit control unit to start the slave unit control unit, and the base unit is configured such that the slave unit control unit is in an operating state after transmitting the synchronization start command. After receiving the synchronization command and starting time measurement of the operation timing control timer, the slave device control unit starts the operation by an operation trigger from the operation timing control timer. After a predetermined operating time has elapsed, the operating state changes to a sleep state.

According to the above configuration, the handset controller causes the operation timing control timer to measure the operation timing, and can enter the sleep state during this time measurement. This enables intermittent operation in the slave device and reduces power consumption. Furthermore, since the operation timing control timer measures the operation timing based on the synchronization command received from the base unit, it is possible to control the operation timing from the base unit to the slave unit, and the operation of the slave unit can be controlled by the base unit. It can be done at the appropriate timing.

Further, in the wireless power supply system, the slave unit is a wireless sensor having a sensing unit, and the slave unit control unit causes the sensing unit to perform a sensing operation during the predetermined operation time, and The sensing data may be configured to be transmitted to the base unit.

According to the above configuration, the wireless power supply system of the present invention can be applied to a wireless sensor system.

Furthermore, in the wireless power supply system, the parent unit can be configured to transmit a data request command to the child unit during the predetermined operating time and receive sensing data in response to the data request command.

According to the above configuration, when there are multiple wireless sensors that are child devices, sensing data can be sent and received in synchronization with data request commands from the parent device, thereby avoiding communication interference between the sensors. Therefore, power consumption during data transmission due to interference can be minimized.

Further, in the wireless power supply system, the base unit is connected to a higher-level system, and the synchronization start command, the synchronization command, and the data request command are issued from the higher-level system and sent to the base unit via the base unit. The sensing data may be transmitted to the slave device, and the sensing data may be transmitted to the host system via the base device.

According to the above configuration, the wireless sensor system can be connected to the higher-level system, and the higher-level system can perform synchronous control of the wireless sensor via the parent device.

The wireless power supply system of the present invention allows the operation timing control timer to time the operation timing based on the synchronization start command and the synchronization command from the base unit, and can put the slave unit control unit in a sleep state during this time measurement. . This has the effect that the power consumption of the handset can be reduced by intermittent operation, and the operation timing of the handsets can be controlled from the master device.

1 is a diagram illustrating a configuration example of a wireless power supply system to which the present invention is applied. FIG. 2 is a functional block diagram showing a schematic configuration of a base unit in the wireless power supply system of FIG. 1. FIG. 2 is a functional block diagram showing a schematic configuration of a wireless sensor in the wireless power supply system of FIG. 1. FIG. FIG. 3 is a diagram showing an operation flow of one cycle of a welding process in the host system. It is a timing chart comparing the operation timing of the welding process in the host system and the wireless sensor system. It is a flowchart of the synchronization process in a parent device. 3 is a timing chart showing communication between a base unit and a sensor in the wireless sensor system.

Embodiments of the present invention will be described in detail below with reference to the drawings.

An example of an application of a wireless power supply system to which the present invention is applied is a wireless sensor system used in a factory or the like. Various robots used in factories etc. require various sensors (for example, position sensors) for robot control, but in order to solve the problem of wiring to the sensors, wireless power supply using microwaves has been developed to connect the sensors to the sensors. may be used to supply power. At this time, the robot control system (upper system) often requires sensing data only at desired timings and does not require sensing data during other periods. For this reason, it is preferable that the wireless sensor operate intermittently so that it operates only during a necessary period and is inactive during other periods.

In the following explanation, an example of a configuration in which the wireless power supply system of the present invention is applied to such a wireless sensor system is given. However, the use of the present invention is not limited to the above example. For example, the child device in the wireless power supply system of the present invention may be any device that receives power from the parent device, performs a predetermined operation, and communicates with the parent device related to that operation, and the child device is not limited to a wireless sensor.

FIG. 1 is a diagram showing a configuration example of a wireless sensor system 10 according to the present embodiment. The wireless sensor system 10 includes a base unit 100 and at least one (three in the example of FIG. 1) wireless sensors (slave units: hereinafter simply referred to as sensors) 200. Furthermore, the master device 100 is connected to the host system 30. The host system 30 here is, for example, a robot control system used in a factory or the like. The master device 100 supplies power to the sensor 200, performs data communication with the sensor 200, and performs synchronization processing with respect to the sensor 200 and data acquisition processing from the sensor 200.

FIG. 2 is a functional block diagram showing a schematic configuration of base unit 100 in wireless sensor system 10. As shown in FIG. Base unit 100 includes a communication/power supply section 110, a control section 120, an I/F section 130, a microwave oscillation section 140, a power supply section 150, and an antenna 160.

The communication/power supply section 110 performs communication with the sensor 200 (transmission of commands and reception of data) and supply of power to the sensor 200 (transmission of power supply waves). The control unit 120 controls the overall operation of the base device 100. The I/F unit 130 is an interface through which the base device 100 communicates with the host system 30. That is, the control unit 120 receives commands from the host system 30 (operation commands for the host system 30 to control the base device 100), and sends sensing data to the host system 30 (sensing data acquired by the base device 100 from the sensor 200). Sensing data), sensor operating status, etc. are transmitted via the I/F unit 130. Note that the communication method between base device 100 and host system 30 is not particularly limited, and may be wired communication or wireless communication. The microwave oscillator 140 oscillates radio waves (microwaves) for communication and power supply signals.

The power supply section 150 supplies operating power to each functional section of the base device 100. In FIG. 2, power supply lines from the power supply section 150 to each functional section are indicated by broken arrows. The antenna 160 radiates radio waves of communication and power feeding signals into space, or receives radio waves of communication signals from space.

FIG. 3 is a functional block diagram showing a schematic configuration of the sensor 200 in the wireless sensor system 10. The sensor 200 includes a communication section 210, a power reception/storage section 220, a control section (child unit control section) 230, a synchronization start command detection section 240, an operation timing control timer 250, a sensing section 260, and an antenna 270. .

The communication unit 210 performs communication with the base device 100 (receiving operation commands and transmitting sensing data and sensor operation status). The power reception/storage unit 220 converts the power supply radio waves from the main unit 100 into DC energy, temporarily stores the DC energy, and supplies the stored electricity to each functional unit of the sensor 200 as operating power. In FIG. 3, power supply lines from the power receiving/storage section 220 to each functional section are indicated by broken arrows.

The control unit 230 controls the overall operation of the sensor 200, and is capable of taking an active state and a sleep state for intermittent operation of the sensor 200. The synchronization start command detection unit 240 detects the signal characteristics of the synchronization start command incorporated in the communication signal received from the base device 100, and activates the control unit 230 when the synchronization start command is detected. The operation timing control timer 250 measures the operation timing set by the synchronization command, and outputs an operation trigger to the control unit 230 when the timing is completed. The sensing unit 260 performs sensing operations under the control of the control unit 230. The antenna 270 receives radio waves of communication and power feeding signals from space, or radiates radio waves of communication signals into space.

Next, the operation of the wireless sensor system 10 will be explained in detail. Here, the host system 30 to which the wireless sensor system 10 is connected is illustrated as a system that performs a welding process in a factory. In this case, the welding process performed by the host system 30 consists of five steps, as shown in FIG. Assume that a cycle is configured. It is assumed that the wireless sensor system 10 is a wireless sensor system for detecting whether a workpiece is appropriately seated at a predetermined position in the seating detection step. In this case, the sensor 200 in the wireless sensor system 10 has a position sensor as the sensing section 260.

FIG. 5 is a timing chart comparing the operation timings of the welding process in the host system 30 and the wireless sensor system 10. The wireless sensor system 10 requires the sensing operation of the sensor 200 (and the transmission of sensing data) in the seating detection step in the welding process, but does not require any other sensing operation. Here, assuming that one cycle time of the welding process is approximately 30 seconds and the step time of seating detection is approximately 3 seconds, the sensor 200 performs sensing operation 90% of the time during the entire process time of one cycle. becomes unnecessary. Therefore, the wireless sensor system 10 can significantly reduce the power consumption of the sensor 200 by causing the sensor 200 to perform intermittent operation.

On the other hand, in order to make the sensing operation of the sensor 200 coincide with the seating detection step in the welding process, it is necessary to control the operation timing of the sensor 200 from the base device 100 side (synchronous control). More specifically, the host system 30 needs to perform synchronous control of the sensor 200 via the base device 100. A method of synchronous control of the sensor 200 will be described below.

As shown in FIG. 5, the wireless sensor system 10 performs synchronization processing at the start of the welding process in the host system 30 and one cycle of operation of the wireless sensor system 10. FIG. 6 is a flowchart of synchronization processing in base device 100. FIG. 7 is a timing chart showing communication between base unit 100 and sensor 200 in wireless sensor system 10. Here, it is assumed that the number of sensors 200 included in the wireless sensor system 10 is N, and the i-th (i=1, 2, . . . , N) sensor 200 is indicated as sensor i.

The synchronization process is sequentially performed for each of the N sensors 200 one by one. Therefore, the base device 100 first sets i=1 (S1 in FIG. 6) and transmits a synchronization start command to the sensor i (S2). As shown in FIG. 6, the sensor i that has received the synchronization start command starts synchronization. Specifically, sensor i starts synchronization as follows.

The sensor i that performs intermittent operation is in a dormant state at the start of one cycle of operation, and the control unit 230 is in a sleep state. When the sensor i receives a synchronization start command in this state, the synchronization start command is detected by the synchronization start command detection section 240. The synchronization start command detection unit 240 that has detected the synchronization start command activates the control unit 230.

Note that the synchronization start command transmitted by the base device 100 needs to be detected by the synchronization start command detection unit 240 when the control unit 230 is in the sleep state. That is, although the synchronization start command is not a command signal that requires processing by the control unit 230, it can be detected by the synchronization start command detection unit 240, as described later.

After transmitting the synchronization start command, base device 100 transmits a synchronization command to sensor i (S3). Upon receiving the synchronization command, the sensor i notifies the base unit 100 that the command has been received, and also causes the operation timing control timer 250 to start timing. The above-mentioned processing accompanying the reception of the synchronization command is performed by the control unit 230 which is activated by the synchronization start command. The control unit 230 that has sent the command reception completion notification goes into a sleep state again, and the sensor i goes into a hibernation state. The above operations complete the synchronization process for sensor i.

After the synchronization process for sensor i is completed (after the control unit 230 goes to sleep), the operation timing control timer 250 measures the operation timing set by the synchronization command, and when the timing of the operation timing is completed, the operation timing control timer 250 transmits a signal to the control unit 230. The control unit 230 is activated by outputting an operation trigger. For example, if the operation timing set by the synchronization command is 8 seconds later, the operation timing control timer 250 outputs an operation trigger to the control unit 230 8 seconds after the start of timing (reception of the synchronization command). Further, the subsequent operation time (for example, 3 seconds) of the control unit 230 activated by the operation trigger may be set by a synchronization command, or may be set in advance on the sensor 200 side.

As a method for detecting a synchronization start command by the synchronization start command detection unit 240, the following example may be given. As a first example, the transmission power of the synchronization start command is made higher than other signals, and when the synchronization start command detection unit 240 receives a signal whose power is higher than a predetermined threshold value, it is detected as a synchronization start command. There is a way. As a second example, there is a method in which a characteristic pattern is included in the synchronization start command, and when the synchronization start command detection unit 240 recognizes the pattern from the received signal, it is detected as a synchronization start command. Such a synchronization start command activates not only the specific sensor i but also the other sensors 200, but the other sensors 200 that are not designated by the subsequent synchronization command go into a dormant state again.

When the synchronization process for sensor i is completed, the base device 100 increases the value of i by 1 (i=i+1) (S4), and if i>N does not hold (NO in S5), the process proceeds to step S2. Go back and repeat steps S2 to S5. By repeating steps S2 to S5, the synchronization process is sequentially performed on the N sensors 200. If i>N (YES in S5), it means that the synchronization process has been completed for all N sensors 200, and the wireless sensor system 10 ends the synchronization process.

When the communication/sensing start time shown in FIG. Control unit 230 starts up. The control unit 230 activated by the operation trigger activates the sensing unit 260 to perform a sensing operation. During the communication/sensing period, the sensing unit 260 of the sensor 200 may perform one sensing operation and transmit sensing data obtained by the sensing operation to the base device 100. Therefore, the sensor 200 in the wireless sensor system 10 can have a rest period in which the control unit 230 is in a sleep state except for the synchronization processing period and the communication/sensing period shown in FIG. As a result, the effect of reducing power consumption due to intermittent operation can be maximized. Regarding the power supply from the master device 100 to the sensor 200, the power supply period can be, for example, a period from synchronization processing to communication/sensing. Of course, the control unit 230 may be in a sleep state during the power supply period.

The operation timing measured by the operation timing control timer 250 is set by a synchronization command from the base unit 100. That is, it becomes possible to control the operation timing of the sensor 200 from the base device 100. Of course, the control of the operation timing of the sensor 200 from the master device 100 is a concept that also includes the control of the operation timing of the sensor 200 by the host system 30 via the master device 100. By controlling the operation timing of the sensor 200 by the higher-level system 30, the higher-level system 30 can acquire sensing data from the sensor 200 at a desired timing.

In this example, the host system 30 can operate the sensor 200 in accordance with the period of the seating detection step of the welding process, and can acquire sensing data at a desired timing during the seating detection step. That is, since the sensor 200 is operating during the seating detection step, if the host system 30 transmits a sensing data request command (data request command) via the base unit 100, the sensing data (or (data on the sensor operating state of the sensor 200) can be acquired.

In this way, since the sensor 200 is in operation during the communication/sensing period, the sensing data transmission process is also performed in synchronization with the data request command from the host system 30. Therefore, even when a plurality of sensors 200 exist, interference in communication between the sensors 200 can be avoided, and power consumption due to data transmission (repetition of data transmission) due to interference can be minimized.

In the wireless sensor system 10 in the above description, the master device 100 is connected to the host system 30, and the operation timing of the sensor 200 is controlled by the host system 30 via the master device 100. That is, a synchronization start command, a synchronization command, and a data request command issued from the host system 30 are transmitted to the sensor 200 via the base device 100. However, the present invention is not limited to this, and in the wireless power supply system of the present invention, the parent device does not need to be connected to the host system. That is, the master device itself may control the operation timing of the slave device.

The embodiment disclosed this time is an illustrative example in all respects, and is not a basis for restrictive interpretation. Therefore, the technical scope of the present invention should not be interpreted only by the above-described embodiments, but should be defined based on the claims. Furthermore, all changes within the meaning and scope of the claims are included.

10. Wireless sensor system (wireless power supply system)
100 Parent unit 110 Communication and power supply unit 120 Control unit 130 I/F unit 140 Microwave oscillator unit 150 Power supply unit 160 Antenna 200 Wireless sensor (child unit)
210 Communication unit 220 Power receiving/storage unit 230 Control unit (child unit control unit)
240 Synchronization start command detection unit 250 Operation timing control timer 260 Sensing unit 270 Antenna 30 Upper system

Claims (4)

A wireless power supply system that wirelessly supplies power from a parent device to a slave device,
The slave device is
a slave unit control unit that controls the operation of the slave unit and is capable of switching between an operating state and a sleep state for intermittent operation;
a synchronization start command detection unit that activates the slave unit control unit by detecting a synchronization start command from the base unit when the slave unit control unit is in a sleep state;
An operation timing in which an operation timing is set based on a synchronization command transmitted from the base unit, and an operation trigger is output to the slave unit control unit to start the slave unit control unit at the time when the set operation timing is completed. Equipped with a control timer,
After transmitting the synchronization start command, the base unit transmits the synchronization command while the slave unit control unit is in an operating state,
The handset control unit receives the synchronization command and starts counting the operation timing control timer, and after a predetermined operation time has elapsed after being activated by an operation trigger from the operation timing control timer. enters the sleep state from the operating state , and after the predetermined operating time passes and enters the sleep state, the synchronization start command detecting section detects the synchronization start command, and the synchronization start command enters the operating state. A wireless power supply system characterized by: The wireless power supply system according to claim 1,
The slave device is a wireless sensor having a sensing section,
The wireless power feeding system is characterized in that the handset control unit causes the sensing unit to perform a sensing operation and transmits sensing data to the base unit during the predetermined operation time. The wireless power supply system according to claim 2,
The wireless power feeding system is characterized in that the parent device transmits a data request command to the child device during the predetermined operating time, and receives sensing data as a reply to the data request command. The wireless power supply system according to claim 3,
The base device is connected to a host system,
The synchronization start command, the synchronization command, and the data request command are issued from the host system and transmitted to the child device via the parent device,
The wireless power supply system is characterized in that the sensing data is transmitted to the host system via the parent device.

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