TWI684777B - Method and system for following target - Google Patents

Abstract

A system and a method for following a target are disclosed. The system includes steps of: A. providing a signal transmitting RF module mounted on a target, a signal receiving RF module on a moving carrier, and at least 3 laser rangefinders aside the signal receiving RF module; B. calculating an estimated distance and a directional angle; C. driving the moving carrier toward the target while maintaining the directional angle substantially 0 degree; D. repeating step B and step C until the estimated distance is shorter than a control exchange distance; E. dynamically tracking the target by one of the laser rangefinders so that a relative distance between said laser rangefinder and the target can be successively calculated while calculating the estimated distance and the directional angle; and F. driving the moving carrier to keep the relative distance within a predetermined range and maintain the normal direction substantially toward the target.

Description

Method and system for following target

The invention relates to a method and system for following a target, in particular to a method and system for following a target using two different detection technologies.

For short walks with items, people can choose a backpack or luggage to put all the items into it. If the size of the items carried is large, a cart or even an electric car may be a good choice for saving energy. For example, when people play golf, the golf cart can carry all the equipment people need in the golf course. However, people may have a one-step demand: can bulky auxiliary equipment follow me at any time? Of course, they need to be smart and motivated.

In real life, such an invention does exist. For example, COWAROBOTTM R1 Smart Luggage provides users with a solution for luggage following. It allows people to let go of their hands and do other things. The smart suitcase includes a wristband worn on the user's hand, which communicates with the smart suitcase wirelessly. On the telescopic pole, there is a group of laser modules. The laser camera is mounted on the handle of the telescopic rod to receive the reflected laser beam from the environment, and further recognizes human images to calculate the position of the person to follow. At the same time, the control module next to the laser camera controls the power wheel module to move when its owner is walking. If the smart suitcase is lost and its owner cannot be found, the wristband will alert you. The owner can go back to where he was to find the smart suitcase. The smart suitcase can help people travel, shop and move heavy objects.

The smart suitcase and related applications have been widely accepted worldwide. In addition to drones, people need assistance equipment to follow them on the ground. However, such a target following system (power wheel modules are not included) is too expensive, and the tracking effect still needs to be improved. Therefore, the present invention aims to provide another useful target following system and related applications to meet the aforementioned needs.

This paragraph extracts and compiles certain features of the invention. Other features will be revealed in subsequent paragraphs. Its purpose is to cover the spirit and scope of the additional patent application scope, various modifications and similar arrangements.

According to one aspect of the invention, a method of following the subject is disclosed. The method includes the steps of: a method of following a target, including the steps of: A. providing a signal transmitting RF module mounted on a target, a signal receiving RF module mounted on a mobile carrier, and providing At least three laser rangefinders next to the signal receiving RF module; B. By calculating the RF signal from the signal transmitting RF module and received by the signal receiving RF module, the signal transmitting RF module and An estimated distance between the signal receiving RF module, and the direction from the signal transmitting RF module to the signal receiving RF module and a front plane where the signal receiving RF module is located on the mobile vehicle A direction angle between a normal direction, where the tracking direction of a first laser rangefinder is substantially along the normal direction for emitting and receiving laser beams; C. driving the moving vehicle towards the target Advance while maintaining the direction angle to be substantially 0 degrees; D. Repeat steps B and C until the estimated distance is shorter than a control exchange distance; E. Dynamically track the target by one of the laser rangefinders so as to be able to Continuously calculating a relative distance between the laser rangefinder and the target while calculating the estimated distance and the direction angle; and F. driving the Move the vehicle to maintain the relative distance within a predetermined range and maintain the normal direction substantially toward the target.

Preferably, the method described further includes steps after steps E and F: E1. Check whether the relative distance is shorter than a predetermined percentage of the control exchange distance or no laser rangefinder has tracked the target; And E2. If any of the conditions in step E1 occur, repeat steps B and C; otherwise, perform step F. The predetermined percentage can be between 50% and 90%

According to the present invention, the method may further include steps after step F: G. Check whether the difference between the direction angle and a relative angle falls within a predetermined angle error range, the relative angle is formed in the normal direction and Between the line from the first laser rangefinder to the target; and H. if the result of step G is yes, repeat step F; if the result of step G is no, repeat steps B and C. The predetermined angle error range may be +3%~-3%.

The normal direction of the normal toward the target can be maintained by: if a second laser rangefinder to the left of the first laser rangefinder tracks the target, turn the moving vehicle to the left until The first laser rangefinder tracks the target, and if a third laser rangefinder to the right of the first laser rangefinder tracks the target, turn the mobile vehicle to the right until the target A laser rangefinder traced the target. The tracking direction of the second laser rangefinder and/or the third laser rangefinder deviates from the tracking direction of the first laser rangefinder to a predetermined angle. The predetermined angle is not greater than 45°. The control exchange distance can be between 1.5m and 2.5m.

According to another aspect of the invention, a system that follows the subject is disclosed. The system includes: a signal transmitting radio frequency module, installed on a target to be followed, working to transmit radio frequency signals; a signal receiving radio frequency module, installed on a mobile carrier, and the signal transmitting radio frequency module Pairing, working to receive the RF signal transmitted by the signal transmitting RF module; at least 3 laser rangefinders are installed beside the signal receiving RF module, each laser ranging The meter calculates a relative distance between itself and the target; and a controller, the signal connects the signal receiving radio frequency module and the at least three laser rangefinders, and operates by transmitting from the signal transmitting radio frequency module and The RF signal received by the signal receiving RF module is calculated as an estimated distance between the signal transmitting RF module and the signal receiving RF module, and the direction from the signal transmitting RF module to the signal receiving RF module and A direction angle between a normal direction of a front plane where the signal receiving radio frequency module is located on the mobile vehicle, sending commands to control the movement of the mobile vehicle, and dynamically ranging from the lasers One of the instruments tracks the target so that the relative distance can be calculated continuously. The tracking direction of a first laser rangefinder is substantially along the normal direction for emitting and receiving laser beams; the controller continuously calculates the estimated distance and the direction angle, and drives the moving vehicle towards the target Move and maintain the direction angle to be substantially 0 degrees until the estimated distance is shorter than a control exchange distance; when the estimated distance is shorter than the control exchange distance, the controller still calculates the estimated distance and the direction angle while driving the movement The vehicle keeps the relative distance within a predetermined range and maintains the normal direction substantially toward the target.

Preferably, when the estimated distance is found to be shorter than the control exchange distance, the controller further checks whether the relative distance is shorter than a predetermined percentage of the control exchange distance or no laser rangefinder has tracked the target; if When any of the above situations occur, the controller uses the estimated distance and the direction angle to drive the moving vehicle. The predetermined percentage may be between 50% and 90%.

According to the present invention, when the controller uses the relative distance and a relative angle, the relative angle is formed between the normal direction and the line from the first laser rangefinder to the target to drive the mobile carrier In time, the controller also checks whether a difference between the direction angle and the relative angle falls within a predetermined angle error range; if the difference falls within the predetermined angle error range, the relative distance and the relative angle are continuously driven The mobile vehicle; if the difference The mobile vehicle is driven with the estimated distance and the direction angle without falling within the predetermined angle error range. The predetermined angle error range may be +3%~-3%.

The normal direction of the normal toward the target can be maintained by: if a second laser rangefinder to the left of the first laser rangefinder tracks the target, turn the moving vehicle to the left until The first laser rangefinder tracks the target, and if a third laser rangefinder to the right of the first laser rangefinder tracks the target, turn the mobile vehicle to the right until the target A laser rangefinder traced the target. The tracking direction of the second laser rangefinder and/or the third laser rangefinder deviates from the tracking direction of the first laser rangefinder to a predetermined angle. The predetermined angle is not greater than 45°. The control exchange distance can be between 1.5m and 2.5m.

In some embodiments, the system may further include an antenna module connected to the signal receiving radio frequency module for receiving signals from the signal transmitting radio frequency module, wherein the antenna module includes: an omnidirectional antenna , Receive signals from the signal transmitting RF module for pairing and stop operation after pairing is completed; and at least 3 directional antennas, each directional antenna receives signals from a specific horizontal angle range, of which any two directional antennas The difference in the central direction angle of the horizontal angle range is a multiple of a fixed angle. When the at least 3-directional antenna cannot receive the signal from the signal transmitting RF module, the omnidirectional antenna can start pairing again.

The method and system for tracking a target provided by the present invention use two techniques to detect the distance between the target and the moving vehicle. When the detected distance is shorter than the control exchange distance, the distance data from the laser rangefinder replaces the distance data from the radio frequency module. Therefore, relative distance following can be applied to the target. At the same time, the system that follows the target can be compactly mounted on any moving carrier, such as a smart luggage or golf cart. Similar products on the market Compared with the product, it can reduce the total cost of the target-made carrier manufactured thereby and improve the tracking ability.

10‧‧‧ target following vehicle

20‧‧‧Subject

100 ‧‧‧ target equipment

110‧‧‧Signal emission RF module

120‧‧‧The first power module

130‧‧‧ First control unit

140‧‧‧Fixed module

150‧‧‧Warning unit

200‧‧‧mobile vehicle

210‧‧‧Housing

211‧‧‧accommodating space

212‧‧‧Fixed board

220‧‧‧Mobile module

221‧‧‧wheel unit

222‧‧‧Motor

223‧‧‧Second control unit

230‧‧‧ Second Power Module

300‧‧‧Subject following assembly

310‧‧‧Signal receiving RF module

320‧‧‧Laser rangefinder

321‧‧‧ First laser rangefinder

322‧‧‧Second laser rangefinder

323‧‧‧third laser rangefinder

330‧‧‧Controller

340‧‧‧ Antenna module

341‧‧‧omnidirectional antenna

342‧‧‧directional antenna

1 is a schematic diagram of a target following vehicle according to the present invention; FIG. 2 shows a schematic diagram of a mobile module; FIG. 3 shows a definition of an estimated distance and a direction angle; FIG. 4 shows an arrangement of a laser rangefinder; Figure 5 shows another arrangement of the laser rangefinder; Figure 6 shows the relationship between a control exchange distance, a relative distance and an estimated distance; Figure 7 shows the arrangement of the antenna; Figure 8 shows an embodiment of the present invention A schematic diagram of a target end device; and FIG. 9 is a flowchart of a method of following a target.

The present invention will be described more specifically by referring to the following embodiments.

Please refer to FIG. 1, which illustrates an embodiment of a target following vehicle 10 according to the present invention. The target follower vehicle 10 includes three main parts: a target end device 100, a mobile carrier 200, and a target follower assembly 300. Detailed descriptions of these components, functions and their interaction will be illustrated with the following related diagrams.

The target terminal device 100 is used to install on a target to be followed. In application, the target may be a person moving on the ground. The target is followed so that certain carried items can be moved accordingly. For example, if the target is a tourist, the target following vehicle 10 can It is a smart suitcase that automatically moves with the tourist. The target following vehicle 10 may also be a golf cart if the target is a golfer. The target terminal device 100 has a signal transmitting RF module 110, a first power module 120, a first control unit 130, and a fixed module 140. The signal transmitting radio frequency module 110 can work to emit a radio frequency signal. In this embodiment, the signal transmitting radio frequency module 110 transmits the radio frequency signal unidirectionally; in other embodiments, the signal transmitting radio frequency module 110 may be bidirectional transmission. That is, the signal transmitting radio frequency module 110 can also receive radio frequency signals.

The first power module 120 is electrically connected to the signal transmitting radio frequency module 110, which can provide power required for operation to any electronic component connected thereto. Because the target end device 100 should be designed as compact as possible so that it does not become a burden on the target, the choice of the first power module 120 should be carefully considered. In practice, the first power module 120 is a low-power secondary battery pack, such as a lithium battery, which can be charged when the power is exhausted or at a low level. For convenience, the first power module 120 may be designed to use a low-power primary battery, such as a mercury battery. The invention is not limited.

The first control unit 130 is electrically connected to the signal transmitting RF module 110 and the first power module 120. The first control unit 130 may take the form of an integrated circuit. The function of the first control unit 130 is to manage the operation of the signal transmitting RF module 110. If possible, the first control unit 130 may be designed to control the power output and recharging of the first power module 120.

The fixing module 140 is installed on the target tool to be followed. Therefore, it can carry the signal transmitting radio frequency module 110, the first power module 120 and the first control unit 130. In practice, the fixed module 140 can be mounted on the target moving part in the form of a wrist strap, such as a human wrist. The fixing module 140 can also be designed as an ornament attached to the sling or installed in the key ring.

The mobile carrier 200 is the main part of the mobile follow-up target. It includes a housing 210, a mobile module 220 and a second power module 230. The housing 210 is used to accommodate items such as clothes purchased by tourists. Therefore, the housing 210 has an accommodating space 211, as shown by the dotted frame in FIG. In this embodiment, the accommodating space 211 is completely enclosed by the housing 210 and can be opened for use when the housing 210 is opened. In other embodiments, the housing 210 may have several openings, and the accommodating space 211 can communicate with the space of the housing 210. A good example of this application is the smart golf cart. The golf equipment may be placed in the accommodating space 211, and the caddy body is the housing 210.

The mobile module 220 is responsible for the movement of the mobile carrier 200, which is integrated with the housing 210 and can move on the ground according to the received commands. According to the present invention, the mobile module 220 may further include several sub-modules, as shown in FIG. 2. The sub-modules are a wheel unit 221, a motor 222 and a second control unit 223. The wheel unit 221 is an element group and has at least two wheels that rotate to push, stop, and rotate the carrier 200. In practice, the wheel set unit 221 may be several non-powered wheels with at least one power wheel, and some wheels can be controlled to change the direction of its axis of rotation (direction wheel). The wheel unit 221 may be a combination of universal wheels. Of course, in order to improve off-road performance, the wheel set unit 221 may be a plurality of track wheels with track attached around it. However, the wheel unit 221 itself has no power. Therefore, the motor 222 is coupled to the wheel unit 221 to output power to drive the wheel unit 221. Any type of motor suitable for driving the designed wheel set unit 221 may be used, and the invention is not limited thereto. If necessary, the number of motors 222 may be more than one to achieve fine direction control or increase the speed.

Like the first control unit 130, the second control unit 223 can be in the form of an integrated circuit, electrically connected to the wheel unit 221 and the motor 222, and can control the wheel unit 221 and the motor 222 according to a command received from a controller 330 Operation.

The second power module 230 is detachably connected to the housing 210. That is, if the mobile vehicle 200 only needs to use its carrying function without the target following function, the second power module 230 can be removed from the housing 210 to reduce the total weight of the mobile vehicle 200 or perform maintenance. Similarly, the second power module 230 works to provide power. Unlike the first power module 120, the second power module 230 must provide higher power and should be rechargeable. Therefore, the second power module 230 should be a high-capacity secondary battery pack.

The target following assembly 300 is a key part for performing the target following and controlling the movement of the mobile vehicle 200, which is installed on the mobile vehicle 200 and electrically connected to the second power module 230, as shown by the dotted line on the right in FIG. In this embodiment, a wire (dotted line on the right) connecting the target following assembly 300 and the second power module 230 is embedded in the housing 210; in other embodiments, the wire may be installed on the surface of the housing 210 (In the accommodation space 211 or the external environment). The target follower assembly 300 should preferably be assembled on the outer surface of the housing 210 or embedded in the housing 210 with a part of it exposed outward. On the one hand, it saves the occupation of the accommodating space 211; on the other hand, the target follower assembly 300 can be easily installed or disassembled for maintenance. The target following assembly 300 includes three sub-modules: a signal receiving radio frequency module 310, at least three laser distance meters 320 and the controller 330. The following is a description of these submodules.

Select the signal receiving RF module 310 according to the signal transmitting RF module 110 in the target terminal device 100, so that the signal receiving RF module 310 can be paired with the signal transmitting RF module 110 and work to receive the signal transmitted from the signal transmitting RF module 110 Radio frequency signal. Similarly, the signal receiving radio frequency module 310 can also send and receive radio frequency signals bidirectionally. the best, The signal receiving RF module 310 and the signal transmitting RF module 110 use 5.8G (802.11a/n/ac) bandwidth. The two RF modules provide data for calculating an estimated distance and a direction angle. For a better understanding, please refer to Figure 3, which defines an estimated distance De and a direction angle θ. The estimated distance De is defined as the distance between the signal transmitting RF module 110 and the signal receiving RF module 310, which is calculated by the RF signal sent from the signal transmitting RF module 110 and received by the signal receiving RF module 310. The estimated distance De is an "estimate" because the RF signal may float when it is sent, resulting in an incorrect calculation of the true distance. The direction angle θ is the direction (solid line) from the signal transmitting RF module 110 to the signal receiving RF module 310 and the normal direction N of a front plane where the signal receiving RF module 310 on the mobile vehicle 200 is located Defined by the angle between them. Here, a fixing plate 212 with a smooth plane is used to install the signal receiving radio frequency module 310 to indicate the normal direction N. In other embodiments, the normal direction N can be defined by any plane of any device on the signal receiving RF module 310 as long as it is not easily changed due to external force or heat. In fact, there are already techniques to calculate the aforementioned estimated distance De and direction angle θ using radio frequency signals, and any technique can be applied to the present invention. The key feature of the present invention is to control the distance between the target and the mobile vehicle 200 through the results of radio frequency signals and at least three laser rangefinders 320.

Please refer to FIG. 4, which shows an arrangement of the laser rangefinder 320. Each laser range finder 320 finds (calculates) an accurate relative distance Dr between the target 20 and itself by the laser beam emitted and reflected by the target 20. The number of laser range finder 320 should be at least 3, such as 3, 4, 5 or more. Preferably, the number should be odd, which means that there will be a central laser rangefinder 320. In this embodiment, in order to simplify the complexity of the target following assembly 300, three laser distance meters 320 are used for illustration. They are a first laser rangefinder 321, a second laser rangefinder 322 on the left side of the first laser rangefinder 321, and a first A third laser rangefinder 323 on the right side of the laser rangefinder 321. A laser range finder 320 has a laser beam emitter (not shown) and a laser beam receiver (not shown). When the emitted laser beam is reflected by the target 20 and received (the first laser rangefinder 321), the relative distance Dr can be obtained. However, when the emitted laser beam is not reflected (the same is true for the second laser rangefinder 322 and the third laser rangefinder 323), there is no available distance data. It also means that the related laser rangefinder 320 cannot detect or track the target 20. No matter how many laser rangefinders 320 are used, they should be installed next to the signal receiving RF module 310. This is because the reference for calculating the distance De and the relative distance Dr should be as close as possible.

Each laser rangefinder 320 has a tracking direction, which is the direction in which the laser beam is emitted. In this embodiment, the three laser rangefinders 320 have different tracking directions. The tracking direction of the first laser rangefinder 321 is 0°, pointing upward. In other words, the tracking direction of the first laser rangefinder 321 is substantially along the normal direction N for emitting and receiving laser beams. The tracking direction of the second laser rangefinder 322 is 10° counterclockwise. The tracking direction of the third laser rangefinder 323 is 10° clockwise. This means that the tracking direction of the second laser rangefinder 322 and/or the third laser rangefinder 323 may deviate from the tracking direction of the first laser rangefinder 321 to a predetermined angle. In this example, the predetermined angle is 10°. Preferably, the predetermined angle may be larger but should not be greater than 45°. In other embodiments, as shown in FIG. 5, the three laser rangefinders 320 have the same tracking direction. However, the second laser distance meter 322 and the third laser distance meter 323 are further away from the first laser distance meter 321. Such an arrangement of laser rangefinder 320 is also within the scope of the present invention. The difference between the arrangement of FIGS. 4 and 5 is that the arrangement in FIG. 4 should be applied to mobile vehicles 200 with a narrow front, such as smart luggage, and the arrangement in FIG. 4 should be applied to mobile with a wide front The vehicle 200, such as a golf cart.

The signal of the controller 330 is connected to the signal receiving RF module 310 and the at least three laser distance meters 320. Meanwhile, in order to issue a command to control the second control unit 223, a connecting line (dotted line on the left) as shown in FIG. 1 is used. Similarly, the connecting wire may be embedded in the housing 210 or on the surface of the housing 210. The controller 330 operates to calculate the estimated distance De and the direction angle θ, issue a command to the second control unit 223 to control the movement of the moving vehicle 200, and dynamically track the target 20 by one of the laser rangefinders 320 So that the relative distance Dr can be calculated continuously.

The present invention uses two techniques to obtain the distance between the target and the tracker itself (laser range finder 320 or signal receiving radio frequency module 310). The controller 330 uses the feedback message from the signal receiving RF module 310 to calculate the estimated distance De and the direction angle θ, so that the absolute position can be identified. At the same time, the controller 330 also uses the results of the laser distance meters 320 to obtain relative position recognition. The accuracy of the latter is better than the former. Therefore, when the target is closer to the controller 330 (the tracker has the same reference), the relative distance Dr can be used to represent the "true distance". The estimated distance De is used when the target is far from the controller 330, because there may be many obstacles between the laser rangefinder 320 and the target, and the relative distance Dr may be incorrect. However, at what distance can the relative distance Dr and the estimated distance De be used? Here, a control exchange distance Dce is defined as the boundary between the relative distance Dr and the estimated distance De. In practice, the relative distance Dr preferably falls between 1.5m and 2.5m. The better case is 2m. Please refer to Fig. 6, which shows the relationship between the control exchange distance Dce, the relative distance Dr and the estimated distance De. In general, the estimated distance De can be very far, ranging from 2m to more than 20m. If the distance between the controller 330 and the target is shorter than the control exchange distance Dce (obtained by the signal receiving radio frequency module 310), the relative distance Dr from the laser rangefinder 320 takes over as the true distance. Although adopted from laser For the distance data of the distance meter 320, the controller 330 continues to calculate the estimated distance De and the direction angle θ to meet occasional needs.

The controller 330 drives the moving vehicle 200 to move toward the target so that the distance therebetween is shortened. At the same time, the controller 330 maintains the directional angle θ to be substantially 0 degrees until the estimated distance is shorter than the control exchange distance Dce. As described above, when the estimated distance De is shorter than the control exchange distance Dce, the controller 330 still calculates the estimated distance De and the direction angle θ while driving the mobile vehicle 200 to maintain the relative distance Dr within a predetermined range and maintain the method The line direction N is substantially toward the target. The predetermined range, for example 0.5 m, is set to keep the moving vehicle 200 away from the target to avoid collision. The normal direction N is substantially toward the target by the following method to maintain the method. Please refer to Figure 4. If the second laser rangefinder 322 to the left of the first laser rangefinder 321 tracks the target 20, this means that the normal direction N has rotated a little clockwise, and you only need to turn the mobile vehicle 200 to the left until The first laser rangefinder 321 tracks to the target 20. The normal direction N is substantially toward the target 20. Conversely, if the third laser rangefinder 323 to the right of the first laser rangefinder 321 traces to the target 20, this means that the normal direction N rotates a little counterclockwise, and only the mobile vehicle 200 needs to Turn right until the first laser rangefinder 321 tracks the target 20. The normal direction N is again substantially toward the target 20.

The frame rate (data acquisition frequency) of the laser range finder 320 and the signal receiving RF module 310 may be dozens of times per second, such as 10 times per second. Therefore, when something or someone quickly enters between the target and the controller 330, it is difficult to find the distance between them. Therefore, there are some special designs to switch the distance decision control to solve the above problems. When the estimated distance De is found to be shorter than the control exchange distance Dce, the controller 330 can further check whether the relative distance Dr is shorter than a predetermined percentage of the control exchange distance Dce, or no laser rangefinder 320 tracks the target. This is to check if someone suddenly breaks in, or the subject is missing. If the article One of the events occurs, and the controller 330 uses the estimated distance De and the direction angle θ to drive the mobile vehicle 200 instead of using the relative distance Dr determined by the laser rangefinder 320. Preferably, the predetermined percentage is between 50% and 90%. In other words, the sudden change of the relative distance Dr can reach 1m or 1.8m. Under another condition, when the controller 330 uses the relative distance Dr and a relative angle, the relative angle is formed between the normal direction N and the line from the first laser rangefinder 321 to the target 20 to drive the movement When carrying the vehicle 200, the controller 330 also checks whether the difference between the directional angle θ and the relative angle falls within a predetermined angle error range. If the difference falls within the predetermined angular error range, the mobile vehicle 200 is continuously driven at the relative distance Dr and the relative angle. If the difference does not fall within the predetermined angular error range, the mobile vehicle 200 is driven with the estimated distance De and the direction angle θ. The predetermined angle error range should not be too large. A preferred example may be +3%~-3%.

According to the present invention, the target following assembly 300 may further include an antenna module 340. The target follower assembly 300 can be connected to the signal receiving RF module 310 to receive the signal from the signal transmitting RF module 110. The antenna module may include an omnidirectional antenna 341 and at least three directional antennas 342. The antenna arrangement is shown in Figure 7. The omnidirectional antenna 341 receives the signal from the signal transmitting RF module 110 for pairing, and it stops operating after the pairing is completed. That is, the omnidirectional antenna 341 is used to establish a connection between the signal transmitting RF module 110 and the signal receiving RF module 310. The number of directional antennas 342 is preferably 3, 5, or 7. Each directional antenna 342 can receive signals from a specific horizontal angle range. For example, the directional antenna 342 marked by a dot receives a signal from the top side of FIG. 7, where a specific horizontal angle range is indicated by two dashed lines. The difference in the central direction angle of the specific horizontal angle range of any two-directional antenna 342 is a multiple of a fixed angle. In FIG. 7, the central directional angle of the specific horizontal angle range of any directional antenna 342 faces the outside along the line between itself and the omnidirectional antenna 341. Direction angle θ It can be determined by the signal received by the directional antenna 342. For example, the two-directional antenna 342 marked with oblique lines receives the signal from the signal transmitting RF module 110. A more accurate directional angle θ can be obtained from the signal strength found in the directional antenna 342. The direction angle θ falling between the central direction angles of the specific horizontal angle range of the two-way antenna 342 is actually closer to the one with the stronger received signal strength.

Sometimes, if the target moves too fast to follow (resulting in the target being farther away from the signal receiving RF module 310) or there is noise in the environment, the signal transmitting RF module 110 and the signal receiving RF module 310 The connection will be interrupted. That is, the at least three-directional antenna 342 cannot receive the signal from the signal transmitting RF module 110. If this happens, the omnidirectional antenna 341 will start pairing again. Thus, the connection can be rebuilt.

In other embodiments, the target device 100 may further include a warning unit 150. See Figure 8. The warning unit 150 is electrically connected to the first control unit 130 and the first power module 120, and it can provide an alarm message. In practice, the warning unit 150 may be a buzzer, LED, miniature speaker, or miniature motor. Therefore, the warning message may be in the form of a buzzer, sound, music, light, or vibration. If the directional antenna 342 cannot receive the signal transmission radio frequency module 110, the controller 330 will issue an alarm signal, and send the alarm message to the warning unit 150 through the signal reception radio frequency module 310 and the signal transmission radio frequency module 110.

According to the present invention, a method of following a target is also provided. Please refer to FIG. 9, which shows the flow of the method. A first step of the method is to provide a signal transmitting RF module mounted on a target, a signal receiving RF module mounted on a mobile carrier, and a signal receiving RF module At least 3 laser rangefinders (S01). The device functions mentioned are the same as the devices with the corresponding names above. Next, the next step is to calculate an estimated distance and a direction angle (S02). The definition of the estimated distance and the direction angle are the same as the definitions disclosed in the previous embodiments The same, no longer repeat. It should be noted that the tracking direction of a first laser rangefinder among the laser rangefinders is substantially along the normal direction disclosed in the previous embodiment for emitting and receiving laser beams.

A third step is to drive the moving vehicle towards the target while maintaining the direction angle to be substantially 0 degrees (S03). In this step, the movement of the moving vehicle towards the target is controlled by position data (estimated distance and direction angle). Next, it is a repetitive loop process of guiding the moving vehicle from calculating the position data: repeating steps S02 and S03 until the estimated distance is shorter than a control exchange distance (S04). The control switching distance has the same definition in the previous embodiment. In practice, the control exchange distance should be between 1.5m and 2.5m.

As mentioned above, once the distance is shorter than the control exchange distance, the distance between the moving vehicle and the target is determined by the laser rangefinder. Thus, the next step is to dynamically track the target by one of the laser rangefinders, so that the relative distance between the laser rangefinder and the target can be continuously calculated while calculating the estimated distance and the direction angle ( S05). Dynamic tracking means that no laser rangefinder is designated to track and find the distance between it and the target. As long as one of the laser rangefinders finds the target, its data can be used until the first laser rangefinder takes over the job. The final step of the method is to drive the moving vehicle to maintain the relative distance within a predetermined range and maintain the normal direction substantially toward the target (S06). The target can be followed in this way.

However, for RF modules and/or laser rangefinders, there are some unpredictable interference distance measurement conditions. Therefore, there must be some additional steps to deal with these problems. Before the data of the laser rangefinder can be used steadily, an inspection step must be taken. for example. After step S05, there are two additional steps: check if the relative distance is shorter than a predetermined percentage of the control exchange distance or there is no laser rangefinder tracking the target (S05-1) and if any of the conditions in step S05-1 occurs, repeat step S02 and step S03; otherwise, execute step S06 (S05-2). Step S05-1 determines whether the relative distance has dropped significantly, or the laser ranging has lost the target originally tracked by the RF module. In other words, it checks whether someone or something suddenly appears between the target and the laser rangefinder, or the laser rangefinder cannot catch the target. If step S05-1 occurs, step S05-2 uses the data calculated by the radio frequency module to determine where the target is now. After determining the target position, the method will continue from step S04. Here, the predetermined percentage should be between 50% and 90%.

In another case, there may be additional steps after step S06. The first step is to check whether the difference between the directional angle and a relative angle falls within a predetermined angular error range, the relative angle is formed in the normal direction and the connection from the first laser rangefinder to the target (S07). The second step is that if the result of step S07 is yes, repeat step S06; if the result of step S07 is no, repeat steps S02 and S03. Steps S07 and S08 are used to deal with the situation where someone suddenly appears between the target and the laser rangefinder, causing different directions to be judged by the RF module. Preferably, the predetermined angle error range is +3%~-3%.

As with the target's following vehicle, this method also provides the same procedure to maintain the normal direction substantially toward the target. This is achieved by the following method: if a second laser rangefinder to the left of the first laser rangefinder tracks the target, turn the moving vehicle to the left until the first laser rangefinder To the target, and if a third laser rangefinder to the right of the first laser rangefinder tracks the target, turn the mobile vehicle to the right until the first laser rangefinder tracks The subject. Preferably, the tracking direction of the second laser rangefinder and/or the third laser rangefinder deviates from the tracking direction of the first laser rangefinder to a predetermined angle. Similarly, the predetermined angle should not be greater than 45°.

Although the present invention has been disclosed as above in the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the attached patent application.

10‧‧‧ target following vehicle

100 ‧‧‧ target equipment

110‧‧‧Signal emission RF module

120‧‧‧The first power module

130‧‧‧ First control unit

140‧‧‧Fixed module

200‧‧‧mobile vehicle

210‧‧‧Housing

211‧‧‧accommodating space

220‧‧‧Mobile module

230‧‧‧ Second Power Module

300‧‧‧Subject following assembly

310‧‧‧Signal receiving RF module

320‧‧‧Laser rangefinder

330‧‧‧Controller

Claims (19)

A method for following a target, including the steps of: A. providing a signal transmitting radio frequency module installed on a target, a signal receiving radio frequency module installed on a mobile carrier, and a signal receiving radio frequency module At least 3 laser rangefinders next to the group; B. By calculating the RF signal sent from the signal transmitting RF module and received by the signal receiving RF module, the signal transmitting RF module and the signal receiving RF module are calculated An estimated distance between the groups and the direction from the signal transmitting RF module to the signal receiving RF module and a normal direction of a front plane where the signal receiving RF module on the mobile vehicle is located A direction angle, where the tracking direction of a first laser rangefinder is along the normal direction for emitting and receiving laser beams; C. driving the moving vehicle towards the target while maintaining the direction angle 0 degrees; D. Repeat steps B and C until the estimated distance is shorter than a control exchange distance; E. Dynamically track the target by one of the laser rangefinders so that the laser range can be calculated continuously A relative distance between the instrument and the target simultaneously calculates the estimated distance and the direction angle; and F. drives the mobile vehicle to maintain the relative distance within a predetermined range and maintain the normal direction toward the target, where when If the relative distance is shorter than a predetermined percentage of the control exchange distance or no laser rangefinder tracks the target, the estimated distance and the direction angle are used instead to drive the mobile vehicle. The method as described in item 1 of the patent application scope further includes steps after steps E and F: E1. Check whether the relative distance is shorter than a predetermined percentage of the control exchange distance or there is no laser rangefinder tracking The subject; and E2. If any of the conditions in step E1 occurs, repeat steps B and C; otherwise, perform step F. The method as described in item 2 of the Patent Application Range, wherein the predetermined percentage is between 50% and 90%. The method as described in item 1 of the patent application scope, further including step after step F: G. Check whether the difference between the direction angle and a relative angle falls within a predetermined angle error range, where the relative angle is the normal The direction and the angle formed by the line from the first laser rangefinder to the target; and H. if the result of step G is yes, repeat step F; if the result of step G is no, repeat step B With step C. The method as described in item 4 of the patent application scope, wherein the predetermined angle error range is +3%~-3%. The method as described in item 1 of the patent application scope, wherein the direction of the normal to the target is maintained by: if a second laser rangefinder to the left of the first laser rangefinder tracks to The target, turn the mobile vehicle to the left until the first laser rangefinder tracks the target, and if a third laser rangefinder to the right of the first laser rangefinder tracks the target , Turn the mobile vehicle to the right until the first laser rangefinder tracks the target. The method according to item 6 of the patent application scope, wherein the tracking direction of the second laser rangefinder and/or the third laser rangefinder deviates from the tracking direction of the first laser rangefinder to a predetermined angle. The method as described in item 7 of the patent application range, wherein the predetermined angle is not greater than 45°. The method as described in item 1 of the patent application scope, wherein the control exchange distance is between 1.5 m and 2.5 m. A target following system includes: a signal transmitting radio frequency module, which is installed on a target to be followed and works to transmit a radio frequency signal; A signal receiving radio frequency module, installed on a mobile vehicle, paired with the signal transmitting radio frequency module, working to receive the radio frequency signal transmitted by the signal transmitting radio frequency module; at least 3 laser rangefinders, installed Located next to the signal receiving RF module, each laser rangefinder calculates a relative distance between itself and the target; and a controller, the signal connects the signal receiving RF module and the at least 3 laser measuring devices A distance meter that operates to calculate an estimated distance between the signal transmitting RF module and the signal receiving RF module by the RF signal sent from the signal transmitting RF module and received by the signal receiving RF module, and by A direction angle between a direction of the signal transmitting RF module to the signal receiving RF module and a normal direction of a normal plane of a front plane where the signal receiving RF module is located on the mobile vehicle is controlled by sending a command The movement of the moving vehicle, and the tracking of the target by one of the laser rangefinders so that the relative distance can be continuously calculated, where the tracking direction of a first laser rangefinder is along the normal direction Used to emit and receive laser beams; the controller continuously calculates the estimated distance and the direction angle, and drives the moving vehicle to move toward the target while maintaining the direction angle at 0 degrees until the estimated distance is shorter than a control exchange distance When the estimated distance is shorter than the control exchange distance, the controller still calculates the estimated distance and the direction angle while driving the moving vehicle to maintain the relative distance within a predetermined range and maintain the normal direction toward the Target; and when the relative distance is shorter than a predetermined percentage of the control exchange distance or no laser rangefinder tracks the target, the estimated distance and the direction angle are used instead to drive the mobile vehicle. The system as described in item 10 of the patent application range, wherein the predetermined percentage is between 50% and 90%. The system of claim 10, wherein when the controller uses the relative distance and a relative angle, where the relative angle is the normal direction and the connection from the first laser rangefinder to the target The angle formed between the lines to drive the mobile vehicle, the controller also checks whether A difference between the directional angle and the relative angle falls within a predetermined angle error range; if the difference falls within the predetermined angle error range, the mobile vehicle is continuously driven at the relative distance and the relative angle; if the difference does not fall Within the predetermined angular error range, the mobile vehicle is driven with the estimated distance and the direction angle. The system as described in item 12 of the patent application scope, wherein the predetermined angle error range is +3%~-3%. The system as described in item 10 of the patent application range, wherein the normal direction toward the target is maintained by: if a second laser rangefinder to the left of the first laser rangefinder tracks to The target, turn the mobile vehicle to the left until the first laser rangefinder tracks the target, and if a third laser rangefinder to the right of the first laser rangefinder tracks the target , Turn the mobile vehicle to the right until the first laser rangefinder tracks the target. The system of claim 14 of the patent application, wherein the tracking direction of the second laser rangefinder and/or the third laser rangefinder deviates from the tracking direction of the first laser rangefinder to a predetermined angle. The system as described in item 15 of the patent application scope, wherein the predetermined angle is not greater than 45°. The system as described in item 10 of the patent application scope, wherein the control exchange distance is between 1.5 m and 2.5 m. The system as described in item 10 of the patent application scope further includes an antenna module connected to the signal receiving RF module for receiving signals from the signal transmitting RF module, wherein the antenna module includes: a full Directional antenna, receiving the signal from the signal transmitting RF module for pairing and stopping operation after pairing is completed; and At least three directional antennas, each directional antenna receives a signal from a specific horizontal angle range, wherein the difference in the central directional angle of the specific horizontal angle range of any two directional antennas is a multiple of a fixed angle. The system of claim 18, wherein when the at least 3-directional antenna cannot receive the signal from the signal transmitting RF module, the omnidirectional antenna starts pairing again.

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