Patent Application
20220185487
The present disclosure relates to a circuit, a base station, a method, and a recording medium.
In recent years, research and development related to drones have been carried out and are attracting interest. Drones are small unmanned aircraft also known as unmanned aerial vehicles (UAVs). According to the economic reports published by the US Association for Unmanned Vehicle Systems International, the market size of drones was about 82 billion dollars in 2025 only in the US, and 1 hundred thousand new jobs are estimated to be created. Drones can provide products and information using air space which has not been used for any means on land, sea, or air. Therefore, drones are also called the industrial revolution of the air and are considered to be important business areas in the future.
For drones, high safety is required because the drones can fly in the sky above buildings or people. As a technology for improving safety related to flight vehicles, for example, Patent Literature 1 discloses a technology for instructing to an unmanned aircraft to use an efficient flight path to an airport stored in advance and having a predetermined facility such as a runway in an emergency situation such as fuel shortage.
Patent Literature 1: JP 2014-181034A
However, a system proposed in Patent Literature 1 is not suitable for a flight vehicle such as a drone in some cases. For example, because drones are small and can go up and down vertically, specific facilities such as airports are not essentially necessary. Further, for example, in consideration of the fact that general drones are light and are easily influenced by a gust of wind, or the like, a situation in which it is difficult to fly to a specific airport can occur suddenly. In such a situation, it is desirable to guarantee safety. Such a circumstance can also occur similarly in devices such as cleaning robots and pet robots that autonomously move, as well as flight vehicles such as drones. Accordingly, the present disclosure provides a structure capable of further improving safety of a device that autonomously moves in an emergency situation.
According to the present disclosure, there is provided a circuit including: a report unit configured to report action-allowable time information regarding an action-allowable time to a base station; and an action control unit configured to control an action of a moving object on the basis of an action instruction decided on the basis of the reported action-allowable time information and notified of by the base station and to control an action with reference to a map in which a danger level for each place is defined in an emergency situation.
Moreover, according to the present disclosure, there is provided a base station including: an acquisition unit configured to acquire action-allowable time information regarding an action-allowable time of a terminal device; and a control unit configured to decide an action of the terminal device on the basis of the action-allowable time information and notify the terminal device of an action instruction, and notify the terminal device of a map in which a danger level for each place is defined and which is used in an emergency situation. Moreover, according to the present disclosure, there is provided a method performed by a processor, the method including: reporting action-allowable time information regarding an action-allowable time to a base station; and controlling an action of a moving object on the basis of an action instruction decided on the basis of the reported action-allowable time information and notified of by the base station and controlling an action with reference to a map in which a danger level for each place is defined in an emergency situation.
Moreover, according to the present disclosure, there is provided a method performed by a processor, the method including: acquiring action-allowable time information regarding an action-allowable time of a terminal device; and deciding an action of the terminal device on the basis of the action-allowable time information and notifying the terminal device of an action instruction, and notifying the terminal device of a map in which a danger level for each place is defined and which is used in an emergency situation.
Moreover, according to the present disclosure, there is provided a recording medium having a program recorded therein causing a computer to function as: a report unit configured to report action-allowable time information regarding an action-allowable time to a base station; and an action control unit configured to control an action of a moving object on the basis of an action instruction decided on the basis of the reported action-allowable time information and notified of by the base station and to control an action with reference to a map in which a danger level for each place is defined in an emergency situation.
Moreover, according to the present disclosure, there is provided a recording medium having a program recorded therein causing a computer to function as: an acquisition unit configured to acquire action-allowable time information regarding an action-allowable time of a terminal device; and a control unit configured to decide an action of the terminal device on the basis of the action-allowable time information and notify the terminal device of an action instruction, and notify the terminal device of a map in which a danger level for each place is defined and which is used in an emergency situation.
According to the present disclosure, as described above, it is possible to provide a structure capable of further improving safety of a device that autonomously moves in an emergency situation. Note that the effects described above are not necessarily limitative. With or in the place of the above effects, there may be achieved any one of the effects described in this specification or other effects that may be grasped from this specification.
Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted.
Note that description will be provided in the following order.
«1. Introduction»
<1.1. Use cases of drone>
Entertainment
Transportation
Public Safety
Informative
Sensing
Worker
Maintenance
<1.2. Wireless communication by drone>
Communication by a drone is also referred to as drone to X (D2X) in some cases. Communication partners of a drone in the D2X communication are considered to be, for example, another drone, a cellular base station, a Wi-Fi (registered trademark) access point, a television (TV) tower, a satellite, a road side unit (RSU), and a human (or a device carried by a human), and the like. A drone can be remotely manipulated via device to device (D2D) communication with a device carried by a human. Further, a drone can also be connected to a cellular system or Wi-Fi for communication. In order to further broaden coverage, a drone may be a connected to a network in which a broadcast system such as TV is used or a network in which satellite communication is used, for communication. In this way, forming various communication links in a drone is considered.
<1.3. General issues related to drone>
«2. Configuration example»
<2.1. System configuration example>
A base station 100A is a macro cell base station which operates a macro cell 11A. The macro cell base station 100A is connected to a core network 12. The core network 12 is connected to a packet data network (PDN) 13 via a gateway device (not illustrated). The macro cell 11A may be operated in accordance with an arbitrary wireless communication scheme such as, for example, long term evolution (LTE), LTE-advanced (LTE-A) and 5G. Note that, it is assumed that 5G includes new radio (NR), new radio access technology (NRAT), and further evolved universal terrestrial radio access (FEUTRA).
Base stations 100B and 100C are small cell base stations which respectively operate a small cell 11B and a small cell 11C. The small cell base stations 100B and 100C are connected to the macro cell base station 100A. The small cells 11B and 11C may be operated in accordance with an arbitrary wireless communication scheme such as, for example, LTE, LTE-A and 5G.
The terminal devices 200 and 300 are devices which perform wireless communication by being connected to cells operated by the base station 100. As illustrated in
Note that, in the following description, in the case where it is not particularly necessary to distinguish between the macro cell base station 100 and the small cell base station 100, these are collectively referred to as the base station 100.
<2.2. Configuration example of base station>
(1) Antenna unit 110
(2) Wireless communication unit 120
(3) Network communication unit 130
(4) Storage unit 140
(5) Processing unit 150
The acquisition unit 151 has a function of acquiring information regarding the drone 200 (state report to be described below). The remote control unit 153 has a function of remotely controlling an action of a moving object (for example, a flight vehicle such as the drone 200) which is a control target. These functions will be described in detail later.
<2.3. Configuration example of drone>
(1) Antenna unit 210
(2) Wireless communication unit 220
(3) Storage unit 230
(4) Flight device 240
The driving unit 241 performs driving for causing the drone 200 to fly. The driving unit 241 includes, for example, a motor, propeller, a transfer mechanism that transfers power of the motor to the propeller, and the like. The battery unit 242 supplies power to each constituent element of the flight device 240. The sensor unit 243 senses various kinds of information regarding a self-state or the periphery of the drone 200. For example, the sensor unit 243 includes a gyro sensor, an acceleration sensor, a positional information acquisition unit (for example, a signal positioning unit of the global navigation satellite system (GNSS)), an altitude sensor, a remaining battery sensor, a rotational sensor of the motor, and the like. The flight control unit 244 performs control for causing the drone 200 to fly. For example, the flight control unit 244 controls the driving unit 241 on the basis of sensor information obtained from the sensor unit 243 such that the drone 200 is caused to fly.
(5) Processing unit 250
The report unit 251 has a function of reporting information to the base station 100. Hereinafter, the information reported to the base station 100 is also referred to as a state report. The action control unit 253 has a function of controlling an action of the drone 200 which is a control target, that is, the drone 200 on which a processing unit 250 is mounted. Hereinafter, an action of the drone 200 performed under the control of the action control unit 253 is simply also referred to as an action of the drone 200. These functions will be described in detail later.
The processing unit 250 is connected to the flight device 240. The processing unit 250 may be realized as a processor, a circuit, an integrated circuit, or the like.
«3. Technical features»
<3.1. Basic operation>
As specific action control methods, the following three kinds of methods shown in Table 1 below are considered.
The first action control method is a method in which the base station 100 takes charge of a decision-making function and a notification function of a decision-making result and the drone 200 takes charge of an action execution function on the basis of a decision-making result. Specifically, the drone 200 (for example, the report unit 251) first transmits a state report to the base station 100 and the base station 100 (for example, the acquisition unit 151) acquires the state report. Subsequently, the base station 100 (for example, the remote control unit 153) performs decision-making in accordance with a decision-making rule and notifies the drone 200 of the decision-making result. A decision-making target is an action of the drone 200 (more exactly, a future action). Then, the drone 200 (for example, the action control unit 253) executes an action on the basis of the decision-making result from the base station 100.
A second action control method is a method in which the base station 100 takes charge of a decision-making function and a notification function of a decision-making result, a relay node takes charge of a relay function, and the drone 200 takes charge of an action execution function based on the decision-making result. Specifically, the drone 200 (for example, the report unit 251) first transmits a state report to the drone 200 via the relay node and the base station 100 (for example, the acquisition unit 151) acquires the state report. Subsequently, the base station 100 (for example, the remote control unit 153) performs decision-making in accordance with a decision-making rule and notifies the drone 200 of the decision-making result via the relay node. Then, the drone 200 (for example, the action control unit 253) performs an action on the basis of the decision-making result from the base station 100. In particular, in the present method, the relay node relays communication between the base station 100 and the drone 200.
A third action control method is a method in which the base station 100 takes charge of a notification function of a decision-making rule and the drone 200 takes charge of a decision-making function and an action execution function based on a decision-making result. Specifically, the base station 100 (for example, the remote control unit 153) first notifies the drone 200 of the decision-making rule. Then, the drone 200 (for example, the action control unit 253) performs decision-making in accordance with the decision-making rule and performs an action on the basis of the decision-making result.
Note that, as the decision-making rule, for example, a mapping table to be described below is adopted. Additionally, any decision-making method such as a neural network may be adopted.
<3.2. First action control method>
First, the base station 100 transmits a state report request to the drone 200 (step S102). Subsequently, the drone 200 transmits a state report to the base station 100 (step S104). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the state report received from the drone 200 (step S106) and transmits an action instruction indicating a decision result to the drone 200 (step S108). Subsequently, in a case in which reception of the action instruction from the base station 100 succeeds, the drone 200 transmits an acknowledgement (ACK, that is, a positive response) to the base station 100. Then, the drone 200 performs an action based on the action instruction received from the base station 100 (step S110).
Hereinafter, the details of each process described with reference to
<3.2.2. Details>
(1) State report request
The state report request includes information for instructing an instruction of information for requesting a report from the drone 200. For example, with regard to the state report request, a report of action-allowable time information regarding a time in which the drone 200 can act (for example, a time in which an action such as flight or photographing is possible) is requested. In a case in which the action-allowable time information includes a plurality of kinds of information, the state report request includes information for designating information in which a report is requested among the plurality of kinds of information.
The state report request may be transmitted periodically at a fixed period or a dynamically adjusted period.
The state report request may be transmitted in conformity with an event trigger scheme. As a transmission trigger, new connection to the base station 100 is considered. In addition, as the transmission trigger, the base station 100 recognizing an apparent change in an environment such as heavy rain or strong wind is considered. In addition, as the transmission trigger, a previous state report request being transmitted and then the base station 100 not succeeding in reception of the state report from the drone 200 even after a predetermined period elapses is considered.
(2) State report
The action-allowable time information can include various parameters. The action-allowable time information includes at least battery information. The battery information is information regarding the battery unit 242. Specifically, the battery information includes, for example, at least one parameter of information indicating a residual battery amount, information indicating a maximum battery capacity, and information indicating power consumption per unit time. In addition, the drone 200 may have, for example, a power generation source such as a solar panel. The battery information may include a parameter related to a generated power amount, a parameter indicating a relation between the generated power amount and a power consumption amount, or the like. In addition, the action-allowable time information may include a parameter indicating an action-allowable time with a numerical value without change (a flight-allowable remaining time in the case of flight).
In addition, the action-allowable time information can include a parameter related to a state or a peripheral environment of the drone 200 in addition to battery information. For example, the action-allowable time information regarding the state of the drone 200 may include at least one of a size (dimensions), a shape, a weight, a material, a shape, a flight altitude, a flight speed, acceleration, a flight direction, a current action, or the like of the drone 200. In addition, action time information regarding the state of the drone 200 may include 3-dimensional geographic information (latitude, longitude, and altitude), the number of propellers, an azimuth, a zenith, an elevation, or the like. Note that, as the current action, flight, photographing, baggage transport, military or detection inspection, takeoff, landing, or the like is considered. On the other hand, the action time information regarding the peripheral environment may include at least one of a temperature, a pressure, rainfall, a wind speed, or a wind direction. In addition, the action time information regarding the peripheral environment may include humidity, visibility, electromagnetic-field strength, electromagnetic-field distribution, nuclear radiation, other weather information (rain, fog, thunder, snow, and hail), or the like.
Note that the parameters may be detected by the drone 200 to be reported or may be estimated by the base station 100 on the basis of the information reported from the drone 200. In addition, once a parameter such as a shape for which a change is rare is reported, the report may be omitted subsequently.
Table 2 below shows examples of sensors mounted on the drone 200 and parameters to be sensed.
The action-allowable time information may be expressed with an absolute value or a relative value. For example, the residual battery amount and the maximum battery capacity may each be expressed with an absolute value. In addition, the residual battery amount may be expressed as a relative value which is a ratio of a residual amount to a maximum capacity.
The drone 200 may control precision of the action time information (for example, calculation precision or expression precision of the foregoing parameter). For example, as the action-allowable time is shorter, the precision of the action time information may be higher (for example, action time information is calculated with high precision or is expressed with high precision). Specifically, in a case in which the residual pattern amount is low, the drone 200 further improves the precision of the parameter. Thus, the drone 200 can report a parameter with high precision in a case in which a crash risk is higher, thereby contributing to a reduction in the increased crash risk.
In general, the drone 200 receives a state report request from the base station 100 and transmits a state report including information requested in the received state report request to the base station 100. In a case in which it is difficult to transmit the requested information, the drone 200 transmits a negative acknowledgement (NACK, that is, a negative response) to the base station 100. Of course, the state report is preferably transmitted rather than the NACK.
Conversely, the drone 200 may transmit the state report to the base station 100 without receiving the state report request.
For example, the drone 200 can transmit the state report request using recognition of a change in the self-state or the peripheral environment as a trigger even when the drone 200 does not receive the state report request. Examples of the transmission trigger include new connection to a network, an increase in altitude, acceleration of a flight speed, handover, a sudden change in temperature, humidity, atmospheric pressure, or the like, and the like. In this case, the action-allowable time information transmitted as a state report also preferably includes a parameter other than the battery information such as temperature.
In addition, the drone 200 can periodically transmit the state report to the base station 100 even when the drone 200 does not receive the state report request. For example, the drone 200 always monitors the self-state and transmits the state report at a period set in advance by the base station 100 while continuously flying as safely as possible. The transmission period of the state report may be changed on the basis of the battery information, weather, or the like. For example, in a case in which the residual battery amount is considerably low, the drone 200 transmits the state report to the base station 100 more frequently. Thus, the drone 200 can transmit the state report more frequently in a case in which a crash risk is higher, thereby contributing to a reduction in the increased crash risk.
The drone 200 switches a report method depending on whether the drone 200 is located within the coverage or outside of the coverage of the base station 100. For example, the drone 200 performs direct reporting in a case in which the drone 200 is located within the coverage of the base station 100. Thus, the drone 200 can minimize a time lag from the transmission of the state report to reception of an action instruction.
(3) Decision-making
The mapping table includes a plurality of conditions related to a state report (in general, action-allowable time information). The base station 100 decides an action associated with a satisfied condition among conditions related to the action-allowable time information as an action (more exactly, a future action) of the drone 200.
For example, the base station 100 decides continuous flight in a case in which the action-allowable time information satisfies a condition in which continuous safe flight is determined to be possible during a period until the drone 200 performs safe landing, and decides landing in other cases. For example, in a case in which the residual battery amount of the drone 200 is found to be equal to or greater than a threshold with reference to the mapping table shown in Table 3 below, the base station 100 decides continuous flight. In a case in which the residual battery amount is less than the threshold, the base station 100 decides emergency landing. In the mapping table, a condition related to comparison between the residual battery amount and the threshold is associated with an action. Specifically, the case in which the residual battery amount is equal to or greater than the threshold is associated with the continuous flight. The case in which the residual battery amount is less than the threshold is associated with the emergency landing.
In addition, in the mapping table, as shown in Table 4 below, a condition including a combination of a plurality of parameters may be associated with an action.
In addition, in the mapping table, as shown in Table 5 below, a condition including a combination of a plurality of thresholds may be associated with an action.
The actions defined in the mapping table include at least an action in a maintaining mode in which the action is maintained and an action in a landing mode in which landing is performed. The maintaining mode can include an all-maintaining mode in which all the current actions continue and a power-saving mode in which some of the current actions continue. In addition, the landing mode can include a preparative landing mode including predetermined landing preparation and an emergency landing mode not including the predetermined landing preparation. Furthermore, in the mapping table, an action in a helping mode and any action such as load delivery or photographing can also be defined. Note that t the drone 200 acting in the emergency landing mode is synonymous with at the drone 200 performing emergency landing. In addition, the base station 100 instructing the drone 200 to act in the emergency landing mode is synonymous with the base station 100 instructing the drone 200 to perform emergency landing. The same applies to the other action modes. Hereinafter, each action mode will be described in detail.
In the all-maintaining mode, the drone 200 continues current actions until a subsequent state report is transmitted. Thereafter, the drone 200 acts on the basis of an action instruction based on the subsequently transmitted state report.
In the power-saving mode, the drone 200 stops or changes unnecessary actions among the current actions and continues only necessary actions. For example, the drone 200 is assumed to receive an action instruction for giving an instruction of an action in the power-saving mode in a situation in which the drone 200 is flying while performing photographing. In this case, for example, the drone 200 slows a flight speed, slows performance (for example, a dynamic range, a resolution, or the like) of the photographing, or stops the photographing and continues only the flight to guarantee safety.
In the preparative landing mode, the drone 200 stops all actions other than actions related to landing and communication with the base station 100. Then, the drone 200 performs landing preparation under the control of the base station 100 while continuously transmitting a state report to the base station 100 at a short period for careful landing preparation, and then performs the landing. Note that another nearby drone 200 collects and records information regarding the drone 200 performing the landing for the purpose of future self-use.
In the emergency landing mode, the drone 200 stops all actions other than actions related to landing or communication with the base station 100. Then, the drone 200 performs the landing without performing predetermined landing preparation. On this account, the drone 200 immediately generates or selects a landing pattern in which damage received or damage caused in the periphery is minimized. The landing pattern includes an appropriate landing direction, landing speed, landing target, landing path, and the like. Thereafter, the drone 200 performs emergency landing (including crashing). At this time, the drone 200 announces a warning to the periphery using a warning lamp, a warning sound or the like.
In the emergency landing mode, a crash map is used. The crash map is a map that is used in an emergency situation and is a map in which a danger level assumed in the case of movement to a place is defined for each peripheral place. The drone 200 controls an action with reference to the crash map in an emergency situation. In the case of the drone 200 that flies, the crash map is a map in which a danger level is defined in a case in which the drone 200 lands on each peripheral place. Referring to the crash map, the drone 200 in flight performs emergency landing, targeting a place with a lower danger level. In a case in which the drone 200 uses a place with a low danger level as a landing place, the drone 200 can be recovered safely and easily. For example, a place with the lowest danger level is a place in which there are no or few buildings. Note that the other nearby drone 200 collects and records information regarding the drone 200 performing the landing for the purpose of future self-use. For example, the other nearby drone 200 can update the crash map on the basis of the collected and recorded information.
Note that the crash map is initially generated by the base station 100 and the drone 200 is notified of the crash map. The crash map may be updated dynamically. For example, the crash map may be updated by the base station 100. In this case, the base station 100 notifies the drone 200 of the newly generated crash map again and updates the crash map. In addition, the drone 200 may update the crash map by itself. For example, the drone 200 updates the crash map on the basis of any event such as detection of danger, for example, in a place considered to be safe in the crash map.
In the helping mode, the drone 200 performs a helping request or helping. For example, the drone 200 acts in the helping mode on a side that makes a request for helping in a case in which the action-allowable time is less than a predetermined threshold. Specifically, the drone 200 requests another drone 200 or a power supply station to supply power. At this time, the drone 200 notifies of urgency to perform interruption. The power supply station is a device that has a purpose of supplying power to another device and can move. The drone 200 may further request another drone 200 or the power supply station to visit its own location. Of course, the drone 200 may move to the power supply station. The power may be supplied in a wired manner or may be supplied wirelessly. In addition, the drone 200 may report so-called flight data to the base station 100. In addition, the drone 200 may make a request for physically exchanging the battery unit 242. The helping request may be transmitted continuously until the helping becomes unnecessary. On the other hand, the drone 200 can act even in the helping mode under a predetermined condition on the side that performs the helping. For example, the drone 200 supplies power in response to a direct helping request from another drone 200 or an indirect helping request via the base station 100. The drone 200 that performs the helping may be designated by the drone 200 that makes the helping request or may be designated by the base station 100.
The action mode may be changed in a case in which the state or the peripheral environment of the drone 200 is changed. For example, in a case in which power is supplied, the drone 200 may change the action mode from the landing mode to the flight mode.
(3) Action instruction
(4) ACK
(5) Execution of action
<3.2.3. Specific example>
(1) First specific example
In the present specific example, the mapping table is assumed to include only conditions related to the comparison between the residual battery amount and the threshold. Here, in the mapping table, one threshold is assumed to be used. A specific example of the mapping table is shown in Table 6 below. Note that a timer related to a response of the state report is assumed to be 500 milliseconds.
It is assumed that the base station 100 transmits a state report request to the drones 200A, 200B, and 200C and state reports shown in Table 7 below are responded.
Referring to the state reports in the mapping table, the base station 100 instructs the drone 200A of which a residual battery amount is less than 30% to perform emergency landing and instructs the drone 200B of which a residual battery amount is equal to or greater than 30% to continue flight (that is, to continue a current action). In a case in which the state report is not received within t0+500 milliseconds from the drone 200C, the base station 100 retransmits the state report request to the drone 200C.
(2) Second specific example
In the present specific example, the mapping table is assumed to include only the condition related to the residual battery amount. Here, in the mapping table, a plurality of thresholds is assumed to be used. A specific example of the mapping table is shown in Table 8 below. Note that a timer related to a response of the state report is assumed to be 500 milliseconds.
It is assumed that the base station 100 transmits a state report request to the drones 200A, 200B, 200C, and 200D and state reports shown in Table 9 below are responded from each drone.
The base station 100 decides an action of each drone 200 with reference to the state report in the mapping table and gives an instruction. For example, the base station 100 instructs the drone 200A of which the residual battery amount is equal to or greater than 60% to continue a current action. Thus, the drone 200A maintains, for example, a flight speed, a flight altitude, a flight direction, and various photographing parameters. In addition, the base station 100 instructs the drone 200B of which the residual battery amount is equal to or greater than 40% and less than 60% to perform an action in the power-saving mode. Thus, for example, the drone 200B slows the flight speed, lowers the flight altitude, and/or lowers photographing parameters such as a dynamic range and a resolution. In addition, the base station 100 instructs the drone 200C of which the residual battery amount is equal to or greater than 20% and less than 40% to perform preparation landing. Thus, the drone 200C performs the landing preparation to land. In addition, the base station 100 instructs the drone 200D of the residual battery amount is less than 20% to perform emergency landing. Thus, the drone 200D stops all the actions other than an action related to landing. Then, the drone 200D selects an optimum landing pattern and starts an emergency landing process. In the emergency landing process, the drone 200D announces a warning to the periphery.
(3) Third specific example
In the present specific example, the drone 200 is located within the coverage of the base station 100 and the mapping table is assumed to include the conditions other than the condition related to the residual battery amount. A specific example of the mapping table is shown in Table 10 below. Note that a timer related to a response of the state report is assumed to be 500 milliseconds.
It is assumed that the base station 100 transmits a state report request to the drones 200A, 200B, and 200C and state reports shown in Table 11 below are responded.
Referring to the state reports in the mapping table, the base station 100 instructs the drones 200A and 200C to land and instructs the drone 200B to continue the flight.
<3.3. Second action control method>
First, the drone 200 transmits a state report to the relay node 400 (step S202). Subsequently, the relay node 400 relays the state report received from the drone 200 to the base station 100 (step S204). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the received state report (step S206) and transmits an action instruction indicating a decision result to the relay node 400 (step S208). Subsequently, when the relay node 400 receives the action instruction, the relay node 400 responds to the base station 100 with ACK (step S210) and relays the received action instruction to the drone 200 (step S212). Then, when the drone 200 receives the action instruction, the drone 200 responds to the relay node 400 with ACK (step S214) and performs an action based on the received action instruction (step S216).
Hereinafter, the details of each process described with reference to
<3.3.2. Details>
(1) Relay node
irst, a case in which the relay node 400 is located within the coverage will be described. The relay node 400 transmits a signal received from the drone 200 outside of the coverage to the base station 100 and transmits a signal received from the base station 100 to the drone 200 outside of the coverage. Note that a role of the relay node 400 can be set in advance by the base station 100. For example, the base station 100 sets a device that is caused to function as the relay node 400 and an area which is in charge of the device. Here, for the coverage which is supplied to the drone 200, an altitude is considered, of course. This is because a change can occur in a direction from the inside of the coverage to the outside of the coverage or its reverse direction in accordance with a flight altitude of the drone 200. Therefore, as the relay node 400, a flight vehicle such as the drone 200 of which an altitude can be adjusted is more appropriate than a thing which is installed on the ground at a fixed altitude.
In general, it is difficult for the drone 200 outside of the coverage to receive a state report request from the base station 100. Accordingly, for example, the drone 200 may transmit the state report periodically. A transmission period can be set in advance by, for example, the base station 100 or a network. In addition, the drone 200 may transmit the state report request using recognition of a change in the self-state or a peripheral environment as a trigger.
In a case in which the drone 200 recognizes that the drone 200 is located outside of the coverage, the drone 200 broadcasts a state report to the periphery. In a case in which the relay node 400 receives the broadcast state report, the relay node 400 relays the state report to the base station 100. The state report transmitted to the relay node 400 preferably includes a parameter such as identification information for identifying the drone 200 which is a transmission source. Thus, the relay node 400 can relay feedback from the base station 100 to the appropriate drone 200.
The case in which the relay node 400 is located within the coverage has been described above. Next, a case in which the relay node 400 is located outside of the coverage will be described.
The relay node 400 comes and goes within and outside of the coverage to relay communication between the base station 100 and the drone 200 outside of the coverage. In this case, the relay node 400 can be referred to as a moving relay. The relay node 400 can be realized as any moving object. Here, for example, a case in which the drone 200 outside of the coverage functions as the relay node 400 will be described with reference to
Accordingly, the relay node 400 is selected from the plurality of drones 200 outside of the coverage. Hereinafter, the drone 200 selected as the relay node 400 is also referred to as a representative. The representative may be set in advance by the base station 100 or may be autonomously selected by the drone 200. In any case, the representative is selected on the basis of a predetermined selection rule. Various selection rules are considered. For example, the representative may be selected in sequence alternately from the plurality of drones 200 which are selection candidates. In this case, any drone 200 is selected periodically as the representative. Additionally, the representative may be selected on the basis of a predetermined standard such as a drone which is the closest to the base station 100 or is in an idle state in which a particular action is not performed. The drone 200 selected as the representative notifies the other nearby drones 200 that the drone 200 is selected as the representative (for example, performs broadcasting). Here, for example, the drone 200A is assumed to be selected as the representative.
As illustrated in the left drawing of
Subsequently, as illustrated in the middle drawing of
Thereafter, as illustrated in the right drawing of
Note that the plurality of drones 200 may be selected as the representative. In this case, which representative relays the state reports of which drones 200 outside of the coverage is preferably set.
(2) Retransmission control
First, the drone 200 transmits a state report to the relay node 400 (step S302) and causes a timer with the length T1 to operate. In a case in which the timer expires before reception of a response to the transmitted state report, the drone 200 retransmits the state report to the relay node 400 (step S304). Subsequently, the relay node 400 relays the state report received from the drone 200 to the base station 100 (step S306). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the received state report and transmits an action instruction indicating a decision result to the relay node 400 (step S308). Subsequently, when the relay node 400 receives the action instruction, the relay node 400 responds to the base station 100 with ACK (step S310) and relays the received action instruction to the drone 200 (step S312). Then, when the drone 200 receives the action instruction, the drone 200 responds to the relay node 400 with ACK (step S314) and performs the action based on the received action instruction (step S316).
First, the drone 200 transmits a state report to the relay node 400 (step S402). Subsequently, the relay node 400 relays the state report received from the drone 200 to the base station 100 (step S404) and causes a timer with the length T2 to operate. In a case in which the timer expires before reception of a response to the transmitted state report, the relay node 400 retransmits the state report to the base station 100 (step S406). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the received state report and transmits an action instruction indicating a decision result to the relay node 400 (step S408). Subsequently, when the relay node 400 receives the action instruction, the relay node 400 responds to the base station 100 with ACK (step S410) and relays the received action instruction to the drone 200 (step S412). Then, when the drone 200 receives the action instruction, the drone 200 responds to the relay node 400 with ACK (step S414) and performs the action based on the received action instruction (step S416).
First, the drone 200 transmits the state report to the relay node 400 (step S502). Subsequently, the relay node 400 relays the state report received from the drone 200 to the base station 100 (step S504). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the received state report, transmits an action instruction indicating a decision result to the relay node 400 (step S506), and causes the timer with the length T3 to operate. In a case in which the time expires before reception of ACK to the transmitted action instruction, the base station 100 retransmits the action instruction to the relay node 400 (step S508). Subsequently, when the relay node 400 receives the action instruction, the relay node 400 responds to the base station 100 with ACK (step S510) and relays the received action instruction to the drone 200 (step S512). Then, when the drone 200 receives the action instruction, the drone 200 responds to the relay node 400 with ACK (step S514) and performs the action based on the received action instruction (step S516).
First, the drone 200 transmits a state report to the relay node 400 (step S602). Subsequently, the relay node 400 relays the state report received from the drone 200 to the base station 100 (step S604). Subsequently, the base station 100 decides an action of the drone 200 on the basis of the received state report and transmits an action instruction indicating a decision result to the relay node 400 (step S606). Subsequently, when the relay node 400 receives the action instruction, the relay node 400 responds to the base station 100 with ACK (step S608), relays the received action instruction to the drone 200 (step S610), and causes the timer with the length T4 to operate. In a case in which the timer expires before reception of ACK to the transmitted action instruction, the relay node 400 retransmits the action instruction to the drone 200 (step S612). Then, when the drone 200 receives the action instruction, the drone 200 responds to the relay node 400 with ACK (step S614) and performs the action based on the received action instruction (step S616).
Note that in consideration of the fact that the drone 200 which is a transmission source of the state report can continuously fly, it is considered that the drone 200 flies from the original place when the action instruction from the base station 100 is relayed by the relay node 400. Accordingly, the relay node 400 may limit the number of times the action instruction is retransmitted to a predetermined number of times (for example, one). In a case in which ACK is not received even when the action instruction is retransmitted the predetermined number of times, the retransmission may be stopped.
<3.4. Third action control method>
First, the drone 200 transmits a mapping table request to the base station 100 (step S702). Subsequently, the base station 100 transmits a mapping table to the drone 200 (step S704). The drone 200 monitors a self-state and a peripheral environment in real time. In a case in which an emergency situation is detected (step S706), the drone 200 transmits a state report to the base station 100 (S708) and causes a timer with a length T5 to operate. In a case in which the timer expires before reception of an action instruction to the transmitted state report, the drone 200 decides a self-action on the basis of the mapping table (step S710). Subsequently, the drone 200 transmits an action report which is information indicating the decided self-action to the base station 100 (step S712). Then, the drone 200 performs the decided self-action (step S714).
<3.4.2. Details>
(1) Mapping table
The mapping table for an emergency situation includes N critical parameters. The critical parameter is a parameter which is monitored by the drone 200. In each of the N parameters, a threshold θi (where i=1, 2, . . . , N) is set. The example is shown in Table 12. Hereinafter, the mapping table including the critical parameters is also referred to as a critical parameter table.
The drone 200 determines an emergency situation on the basis of a comparison result between a threshold and a sensing result of the critical parameter. For example, the drone 200 determines an emergency situation in a case in which the number of critical parameters satisfying conditions greater or less than the thresholds, or the like exceeds k, and determines a normal state (that, safety) in other cases. Here, in a case in which a specific critical parameter such as a residual battery amount or a wind speed is greater or less than the threshold, an emergency situation may be determined even when k conditions are not satisfied. This critical parameter can also be referred to as a key critical parameter.
The critical parameter table may be unicast to the drone 200, for example, at a timing at which the drone 200 is newly connected to a network. In addition, the critical parameter table may be multicast to a group of the drones 200, for example, at a timing at which the group is newly connected to the network.
The base station 100 may transmits the critical parameter table in response to a request, as illustrated in
(2) Timer
(3) Decision-making
(4) Action report
A state report may be transmitted along with the action report. The state report may include content of a state report for which there is no response to a corresponding action instruction. That is, the state report transmitted in step S712 of the sequence illustrated in
<3.4.3. Specific example>
Each of the drones 200A, 200B, 200C, and 200D monitors the parameters shown in Table 13 above in real time. Key critical parameters are a residual battery amount and a wind speed. In a case in which the residual battery amount is less than 10% or a wind speed is greater than 15 m/s, each of the drones 200A, 200B, 200C, and 200D determines an emergency situation. Note that the threshold k which is a condition number is assumed to be 2. Table 14 below shows specific examples of the critical parameters of the drones 200A, 200B, 200C, and 200D.
The drone 200A determines an emergency situation since the residual battery amount is 5% which is less than a threshold of 10%. The drone 200B determines an emergency situation since a wind speed is 25 m/s which is greater than a threshold of 10 m/s. The drone 200C determines an emergency situation since a weight is 10 kg greater than a threshold of 3 kg, a flight speed is 30 m/s greater than a threshold of 10 m/s, relative humidity is 70% which is greater than a threshold of 50%, and the number of critical parameters satisfying the conditions is 3 greater than a threshold of 2. The drone 200D determines a normal state since a weight is 10 kg greater than the threshold of 3 kg and the number of critical parameters satisfying the conditions is 1 less than the threshold of 2. Therefore, the drones 200A, 200B, and 200C perform the emergency landing and the drone 200D continues the flight.
<3.5. Crash map>
As illustrated in the left drawing of
In the example illustrated in
As illustrated in the left drawing of
Each of the base station 100 and the drone 200 can update the crash map. In general, the crash map is updated using a change in an environment as a trigger. This point will be described with reference to
As illustrated in the upper left drawing of
<3.6. Drone category>
(1) Background
However, in the UE categories, parameters related to flight are not considered. In the case of a drone, parameters such as a flight altitude related to flight can have a nonnegligible influence on communication between the drone and another node such as an eNB. For example, an influence on uplink and downlink peak speeds, a maximum frequency bandwidth, and the like can occur. In a case in which a drone uses the existing UE categories, many troubles related to communication can occur.
Accordingly, it is desirable to define categories in which parameters particularly related to flight are considered.
(2) Drone category
The drone category is defined by the base station 100 or a network. At this time, a drone category table including definition of one or more drone categories is configured. The base station 100 or a control node transmits the drone category table to the drone 200 and the drone 200 responds with ACK. Referring to the received drone category table, the drone 200 can specify a self-drone category. Then, the drone 200 reports the self-drone category to the base station 100. Thus, the base station 100 can realize efficient communication in which the flight of the drone 200 is considered.
When the drone 200 transmits, for example, a request for the mapping table, the drone 200 can make a request to transmit the drone category table in order to know the self-drone category. On the other hand, even in a case in which the drone 200 transmits a request for the mapping table without transmitting a request for the drone category, the base station 100 may transmit the drone category table.
In addition, the mapping table for decision-making related to the drone 200 can differ depending on the drone category of the drone 200. That is, referring to the mapping table in accordance with the drone category of the drone 200, the base station 100 can decide an action of the drone 200.
An example of the drone category table is shown in Table 15 below. In the drone category, parameters such as a size, a weight, and a maximum flight altitude related to flight are defined as parameters which are not in the UE categories. In future, the drone category can be extended including any flight vehicle such as an airplane or a satellite other than the drone as a target.
Note that return to departure (RTD) means return to a takeoff place. For example, a distance or a time up to a takeoff place is defined in Table 15 above. In a case in which it is necessary for the drone 200 to return to a takeoff place, it is preferable to define a parameter related to RTD.
Table 16 below shows three specific examples of the drone category.
«4. Application examples»
(First application example)
The base station device 820 includes a controller 821, a memory 822, a network interface 823, and a wireless communication interface 825.
The controller 821 may be, for example, a CPU or a DSP, and operates various functions of an upper layer of the base station device 820. For example, the controller 821 generates a data packet from data in a signal processed by the wireless communication interface 825, and transfers the generated packet via the network interface 823. The controller 821 may generate a bundled packet by bundling data from a plurality of base band processors to transfer the generated bundled packet. Further, the controller 821 may also have a logical function of performing control such as radio resource control, radio bearer control, mobility management, admission control, and scheduling. Further, the control may be performed in cooperation with a surrounding eNB or a core network node. The memory 822 includes a RAM and a ROM, and stores a program executed by the controller 821 and a variety of control data (such as, for example, terminal list, transmission power data, and scheduling data).
The network interface 823 is a communication interface for connecting the base station device 820 to the core network 824. The controller 821 may communicate with a core network node or another eNB via the network interface 823. In this case, the eNB 800 may be connected to a core network node or another eNB through a logical interface (e.g., S1 interface or X2 interface). The network interface 823 may be a wired communication interface or a wireless communication interface for wireless backhaul. In the case where the network interface 823 is a wireless communication interface, the network interface 823 may use a higher frequency band for wireless communication than a frequency band used by the wireless communication interface 825.
The wireless communication interface 825 supports a cellular communication system such as long term evolution (LTE) or LTE-Advanced, and provides wireless connection to a terminal located within the cell of the eNB 800 via the antenna 810. The wireless communication interface 825 may typically include a base band (BB) processor 826, an RF circuit 827, and the like. The BB processor 826 may, for example, perform encoding/decoding, modulation/demodulation, multiplexing/demultiplexing, and the like, and performs a variety of signal processing on each layer (e.g., L1, medium access control (MAC), radio link control (RLC), and packet data convergence protocol (PDCP)). The BB processor 826 may have part or all of the logical functions as described above instead of the controller 821. The BB processor 826 may be a module including a memory having a communication control program stored therein, a processor to execute the program, and a related circuit, and the function of the BB processor 826 may be changeable by updating the program. Further, the module may be a card or blade to be inserted into a slot of the base station device 820, or a chip mounted on the card or the blade. Meanwhile, the RF circuit 827 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal via the antenna 810.
The wireless communication interface 825 may include a plurality of the BB processors 826 as illustrated in
In the eNB 800 illustrated in
Further, in the eNB 800 illustrated in
(Second application example)
Each of the antennas 840 includes a single or a plurality of antenna elements (e.g., antenna elements constituting a MIMO antenna), and is used for the RRH 860 to transmit and receive a wireless signal. The eNB 830 may include a plurality of the antennas 840 as illustrated in
The base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857. The controller 851, the memory 852, and the network interface 853 are similar to the controller 821, the memory 822, and the network interface 823 described with reference to
The wireless communication interface 855 supports a cellular communication system such as LTE and LTE-Advanced, and provides wireless connection to a terminal located in a sector corresponding to the RRH 860 via the RRH 860 and the antenna 840. The wireless communication interface 855 may typically include a BB processor 856 or the like. The BB processor 856 is similar to the BB processor 826 described with reference to
The connection interface 857 is an interface for connecting the base station device 850 (wireless communication interface 855) to the RRH 860. The connection interface 857 may be a communication module for communication on the high speed line which connects the base station device 850 (wireless communication interface 855) to the RRH 860.
Further, the RRH 860 includes a connection interface 861 and a wireless communication interface 863.
The connection interface 861 is an interface for connecting the RRH 860 (wireless communication interface 863) to the base station device 850. The connection interface 861 may be a communication module for communication on the high speed line.
The wireless communication interface 863 transmits and receives a wireless signal via the antenna 840. The wireless communication interface 863 may typically include the RF circuit 864 or the like. The RF circuit 864 may include a mixer, a filter, an amplifier and the like, and transmits and receives a wireless signal via the antenna 840. The wireless communication interface 863 may include a plurality of the RF circuits 864 as illustrated in
In the eNB 830 illustrated in
Further, in the eNB 830 illustrated in
«5. Conclusion»
In addition, the base station 100 notifies the drone 200 of the crash map in which a danger level for each peripheral place is defined and which is used in an emergency situation. Then, the drone 200 acts referring to the map in which the danger level for each peripheral place is defined in the emergency situation. Thus, the drone 200 can perform emergency landing in a place in which harm is minimized in the case of landing in the emergency situation.
In addition, the drone 200 can monitor a self-state and make a decision autonomously. In this case, the drone 200 can reduce overhead of communication and delay of an action in the emergency situation compared to a method of transmitting a state report to the base station 100 and receiving an action instruction. Thus, it is possible to further improve the safety of the drone 200 in an emergency situation.
The preferred embodiment of the present disclosure has been described above with reference to the accompanying drawings, whilst the present disclosure is not limited to the above examples. A person skilled in the art may find various alterations and modifications within the scope of the appended claims, and it should be understood that they will naturally come under the technical scope of the present disclosure.
Further, the drone 200 is not limited to a drone in a narrow sense. For example, the drone 200 may be an arbitrary flight vehicle controlled via cellular communication. In addition, the present technology can also be applied to devices such as cleaning robots and pet robots that autonomously move, as well as flight vehicles.
Further, the processing described using the sequence diagrams in the present specification does not necessarily have to be executed in the illustrated order. Some processing steps may be executed in parallel. Further, additional processing steps may be employed, or part of the processing steps may be skipped.
Further, the effects described in this specification are merely illustrative or exemplified effects, and are not limitative. That is, with or in the place of the above effects, the technology according to the present disclosure may achieve other effects that are clear to those skilled in the art from the description of this specification. Additionally, the present technology may also be configured as below.
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| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-216051 | Nov 2016 | JP | national |
This application is a continuation application of U.S. patent application Ser. No. 16/337,233, filed on Mar. 27, 2019, is a U.S. National Phase of International Patent Application No. PCT/JP2017/036379 filed on Oct. 5, 2017, which claims priority benefit of Japanese Patent Application No. JP 2016-216051 filed in the Japan Patent Office on Nov. 4, 2016. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16337233 | Mar 2019 | US |
| Child | 17689619 | US |
