CN113495558A

CN113495558A - Guiding machine and control method of navigation system

Info

Publication number: CN113495558A
Application number: CN202010733988.8A
Authority: CN
Inventors: 陈晓升; 李广波; 李健强; 赵樑
Original assignee: Logistics and Supply Chain Multitech R&D Centre Ltd
Current assignee: Logistics and Supply Chain Multitech R&D Centre Ltd
Priority date: 2020-03-19
Filing date: 2020-07-24
Publication date: 2021-10-12

Abstract

The invention discloses a control method of a guiding machine and a navigation system. The navigation system includes: a plurality of signal sources disposed in a predetermined area; and a directing machine comprising a signal receiver arranged to receive electromagnetic signals emitted from one or more of a plurality of signal sources; and a processor arranged to process the electromagnetic signals to identify the location of the signal source and to determine a current position of the guiding machine therefrom with reference to the location of the signal source; and the processor is further arranged to determine a path for the guiding machine to travel from the current position to a destination location in the predetermined area.

Description

Guiding machine and control method of navigation system

Technical Field

The present invention relates to a control method for a guide machine and navigation system, and in particular, though not exclusively, to a robotic guide dog based on RFID technology.

Background

A common tool for presenting directional or guiding information to a user or customer is the use of visual markers or reference points to convey guiding and positioning information to the user. However, for visually impaired people, the visual indicia may not be useful or provide any significant assistance, and thus, an alternative form of navigational assistance is needed.

Tactile markings (e.g., tactile tiles laid on a floor surface) may be one possible solution to aid navigation for visually impaired people. These tactile markings may have a predetermined shape and layout that provides a tactile sensation to the user when stepping on or touching the tile. These tactile markings, while helpful in providing reference information, are limited in the assistance they provide to the user.

Alternatively, some users may prefer the relatively positive help provided by blind guide dogs that are professionally trained to guide the user to travel to different destinations. However, blind guides can often be trained to remember only a few fixed routes and destination points, thereby limiting where blind persons may travel by relying on blind guides.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a method of controlling a steering machine, comprising the steps of: receiving electromagnetic signals emitted from one or more signal sources of a plurality of signal sources disposed in a predetermined area; processing the electromagnetic signals to identify a location of the signal source; determining the current position of the guiding machine by referring to the positioning of the signal source; and determining a path for the guiding machine to travel from the current location to a destination in the predetermined area.

In an embodiment of the first aspect, the electromagnetic signal is transmitted in an orthogonal direction.

In an embodiment of the first aspect, the electromagnetic signal is transmitted in a linear polarization.

In an embodiment of the first aspect, each of the plurality of signal sources is arranged to emit electromagnetic signals in two orthogonal directions along a plane.

In an embodiment of the first aspect, the step of processing the electromagnetic signal comprises: the distance and direction of each signal source is determined based on the signal strength of each electromagnetic signal emitted by each signal source in two orthogonal directions.

In an embodiment of the first aspect, the step of receiving the electromagnetic signal comprises: receiving signals from the plurality of signal sources through a plurality of antennas surrounding the director along the plane.

In an embodiment of the first aspect, the step of receiving an electromagnetic signal further comprises the steps of: sequentially receiving electromagnetic signals in each respective direction of the plurality of antennas in each detection interval.

In an embodiment of the first aspect, the method further comprises the steps of: detecting an obstacle on the path; and determining an alternate path for the guidance machine to travel from the current location to the destination.

In an embodiment of the first aspect, the method further comprises the steps of: notifying a user of the guidance machine of the detection of the obstacle.

In an embodiment of the first aspect, the method further comprises the steps of: using the haptic signal, instructions are provided to a user of the guidance machine relating to traveling along the path.

In an embodiment of the first aspect, the haptic signal comprises vibration signals having different vibration modes, frequencies and/or intensities.

According to a second aspect of the present invention, there is provided a navigation system comprising: a plurality of signal sources disposed in a predetermined area; a director machine including a signal receiver arranged to receive electromagnetic signals emitted by one or more of a plurality of signal sources; and a processor arranged to process the electromagnetic signals to identify the location of the signal source and to determine a current position of the guiding machine therefrom with reference to the location of the signal source; and the processor is further arranged to determine a path for the guiding machine to travel from the current location to a destination in the predetermined area.

In an embodiment of the second aspect, the electromagnetic signal is transmitted in an orthogonal direction.

In an embodiment of the second aspect, the electromagnetic signal is transmitted in a linear polarization.

In an embodiment of the second aspect, each of the plurality of signal sources is arranged to emit electromagnetic signals in two orthogonal directions along a plane.

In an embodiment of the second aspect, the processor is arranged to determine the distance and direction of each signal source based on the signal strength of each electromagnetic signal emitted by each signal source in two orthogonal directions.

In an embodiment of the second aspect, the director comprises a plurality of antennas surrounding the director along the plane, the antennas being arranged to receive signals emanating from a plurality of signal sources.

In an embodiment of the second aspect, the signal receiver is arranged to: sequentially receiving electromagnetic signals in each respective direction of the plurality of antennas in each detection interval.

In an embodiment of the second aspect, the plurality of antennas comprises a plurality of unidirectional antennas.

In an embodiment of the second aspect, the plurality of antennas are electromagnetically separated so as to minimize mutual coupling between adjacent pairs of antennas.

In an embodiment of the second aspect, the director further comprises an electromagnetic isolator disposed between each of the adjacent pairs of antennas.

In an embodiment of the second aspect, the signal reader comprises a multi-channel RFID reader.

In an embodiment of the second aspect, each of the plurality of signal sources comprises two orthogonally arranged RFID tags.

In an embodiment of the second aspect, the guiding machine further comprises at least one sensor arranged to detect obstacles on the path.

In an embodiment of the second aspect, the processor is further arranged to: in response to detecting the obstacle, determining an alternate path for the guidance machine to travel from the current location to the destination.

In an embodiment of the second aspect, the at least one sensor comprises at least one of an infrared sensor and an ultrasonic sensor.

In an embodiment of the second aspect, the guiding machine further comprises a handle arranged to provide instructions to a user of the guiding machine relating to travelling along the path using tactile signals.

In an embodiment of the second aspect, the haptic signal comprises vibration signals having different vibration modes, frequencies and/or intensities.

In an embodiment of the second aspect, the navigation system further comprises an input module arranged to receive an input of said destination in said predetermined area.

In an embodiment of the second aspect, the guiding machine comprises a robotic guiding vehicle.

Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram showing a guidance machine and four RFID signal sources of a navigation system according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating exemplary operation of the navigation system of FIG. 1 when a user navigates to a destination along a path determined by the navigation system using a navigation machine; and

FIG. 3 is a diagram illustrating exemplary operation of the navigation system of FIG. 2 when the guiding machine detects an obstacle and determines an alternate path for the user.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Referring to FIG. 1, an embodiment of a navigation system 100 is shown, comprising: a plurality of signal sources 102 disposed in a predetermined area; a director 104 comprising a signal receiver arranged to receive electromagnetic signals emitted from one or more of the plurality of signal sources 102; and a processor arranged to process the electromagnetic signals to identify the location of the signal source 102, thereby determining the current position of the guiding machine 104 with reference to the location of the signal source 102; and the processor is further arranged to determine a path for the guiding machine 104 to travel from the current position to the destination location in the predetermined area.

In this embodiment, the director 104 has four wheels 106 for driving the director 104 along a surface (e.g., the ground). The guide 104 also includes a handle 108 that can be held by a user so that the guide 104 can navigate and actively guide the user to move from one location to another. In one example, the guidance machine 104 may be used as a robotic guide vehicle or a robotic guide dog for a visually impaired user.

Preferably, only wheels are provided to facilitate smooth movement of the director over a surface. Alternatively, the one or more wheels may be active wheels or motorized wheels, which may assist the user in walking along the path.

The handle 108 may also provide instructions to the user of the steering engine 104 regarding traveling along the path using tactile signals. Alternatively, other ways of providing guidance/navigation information to the user may be used, such as, but not limited to, audio signals that may be provided directly to the user via headphones.

Referring to fig. 1, the director 104 also includes four antennas 120 around the director 104, preferably on each side of the director 104 when placed on a flat surface. The plurality of antennas 120 is arranged to receive signals emanating from the signal source 102. By determining the distance and direction of each of the plurality of signal sources 102 fixed on a plane, the steering engine 104 may determine the current position, for example, using triangulation.

For example, the signal source 102 may be an array of RFID tags below the ground surface, and the tags 102 may issue RFID signals containing the UID of the tags to an RFID reader (not shown) in the director 104. The RFID reader may be a multi-channel RFID reader and the antenna 120 may be a separately activatable RFID antenna.

Preferably, the electromagnetic signals are transmitted in orthogonal directions, for example by deploying the signal source 102 below the ground surface, and during operation, the RFID signal source 102 may emit electromagnetic signals in two orthogonal directions along a (2D) plane. Referring to FIG. 1, at each location having a signal source 102, two orthogonally arranged RFID tags (102X and 102Y) have been deployed, and thus, the signals emanating from the two tags (102X and 102Y) will include signals emanating in the X and Y directions. Alternatively, a single tag that signals in orthogonal directions may be used.

Preferably, the plurality of antennas 120 may be unidirectional antennas such that when one of the antennas 120 is activated, the antenna 120 may communicate with the RFID tag 102 "facing" the antenna 120. For example, the right antenna 120 may communicate with tags 102 on the right side of the director 104, particularly only those tags 102X that emit RF signals in the X direction. Advantageously, this allows the processor to more accurately extract information associated with the angular position of the tag 102 relative to the guide 104.

In alternative embodiments, more antennas may be used to enhance the accuracy of the navigation system by providing more positioning information to the processor. For example, 4 additional antennas may be mounted on the corners of the director 104, totaling a total of 8 antennas, the antennas being radially distributed around the director 104.

Alternatively or additionally, the plurality of antennas 120 are electromagnetically separated so as to minimize mutual coupling between adjacent pairs of antennas 120, for example by providing an electromagnetic isolator (not shown) disposed between each adjacent pair of antennas.

After receiving the necessary location information from the tag 102, the processor will be able to determine the distance and direction of each signal source 102 based on the signal strength of each electromagnetic signal emitted in two orthogonal directions by each respective signal source 102.

For example, referring to FIG. 1, the antenna 120 on the left side of the director 104 is closer to the tag 102 on the left side, and therefore has a higher signal strength than the source-antenna pair on the right side. The processor may determine that the director 104 is now in a position closer to the left column of the RFID tag array than the right column of the RFID tag array by analyzing the signal parameters and estimating the relative position of the tags 120 accordingly.

Preferably, the signal receiver is arranged to sequentially receive the electromagnetic signal in each respective direction of the plurality of antennas 120 in each detection interval, so that all tags 102 within detectable range of the lead machine 104 will be periodically detected. The processor may then update the current position of the steering engine 104 from time to time.

Referring to fig. 2 and 3, exemplary operation of the steering engine 104 being used by a user is shown. In this example, the navigation system 100 can be used as a blind guidance system based on RFID within a defined area.

In this example, the navigation system 100 includes a guidance machine 104, the guidance machine 104 including a processor, a rumble pad 108, a multi-channel RFID reader, and a set of RFID antennas 120. An array of RFID tags 102 has been installed underground. The body 104 is a movable part of the system 100 and it can be moved over the area by installing an array of RFID tags. Preferably, the body 104 includes a processor, a vibrating handle 108, a multi-channel RFID reader, and a set of RFID antennas 120.

Extending from the body 104, a (rear) handle 108 is provided, which may be gripped by a user 122 when in use. The handle 108 may include or be connected to a vibration generator to provide tactile signals to a user 122 holding the handle. Preferably, the haptic signals include vibration signals having different vibration patterns, frequencies, and/or intensities, which may represent different directional information to be provided to the user 122. The handle 108 may also vibrate at different frequencies indicating different conditions.

In a preferred example, the processor may control the movement of the vehicle body and receive signals from the multichannel RFID reader through a set of RFID antennas 120 and the vibration frequency of the handle 108.

A set (4 to 8 antennas) of RFID antennas 120 is mounted around the body 104 and connected to a multi-channel RFID reader housed within the body 104. During each detection period, only a single antenna may be sequentially turned on. The antenna radiation is preferably unidirectional and all antennas 120 are pointing in different directions. As a result, the processor can accurately distinguish the received RFID signal strengths from all antennas 120.

As previously discussed, isolators may be installed between adjacent antenna elements in the group to reduce mutual coupling between the antennas 120. The inventors have designed an isolator that does not degrade antenna performance, but it makes it easier for the processor to distinguish from which antenna element the largest signal is received.

The RFID tag array may be uniformly installed and distributed over the entire surface of the ground. Each RFID tag 102 can receive and transmit electromagnetic waves in a linearly polarized manner. In addition, two orthogonal RFID tags are installed at the same position and record information of the same position point. The processor also reads the strength of the signal from the RFID tag 102 and thus estimates the location of the vehicle body 104 by comparing the received signal strengths.

During each detection interval, the processor determines the received signal strength and the average of all received signals over a small interval. The tag ID may be associated with location information for all RFID tags 102 and stored in a database. The system 100 may further comprise an input module arranged to receive an input of a destination in the predetermined area, the input allowing a user to input a start point and a destination/end point. For example, the user may enter the desired destination by entering geometric coordinates directly into the system or director 104 or simply entering the UID of a particular tag. Alternatively, the input may also be provided to the guidance machine via other means (e.g., inputting a location to a smartphone), which may further communicate to the system 100 or the guidance machine 104.

After determining the current location of the guidance machine 104, the processor may further determine the best path for the guidance machine 104 to travel toward the destination with reference to map data that stores all positioning information for the tags 102.

Alternatively or additionally, the guidance machine 104 further comprises at least one sensor (not shown) arranged to detect an obstacle 124 on the path, and in response to detecting the obstacle 124, the processor determines an alternative path for the guidance machine 104 to travel from the current location to the destination.

Referring to fig. 3, the navigation machine 104 also collects sensed data from the ultrasonic and/or infrared sensors upon detection of an obstacle 124, which obstacle 124 prevents the user from reaching the destination by following the previously obtained optimal path. Preferably, the process recalculates or modifies the best path so that the user can reach the destination by following an alternate path.

The processor may also control the vibration of the handle 108 once the processor 108 has modified the optimal path and notified the user that an obstacle 124 was encountered in front. It also allows the user to notice that the path is about to change. For example, by changing the vibration level of the handle 108, the user may then know that he should continue walking, turn right or left, or stop.

These embodiments may be advantageous because the interactive robotic guidance vehicle may provide accurate navigation information to blind users, which may be similar to relying on a guide dog so that the user may easily switch to use a new interactive navigation system.

Advantageously, the combined use of multiple unidirectional antennas and the deployment of orthogonally arranged RFID arrays provides a simple and elegant solution to accurately determine the position of a steering engine.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Any reference to prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise indicated.

Claims

1. A method of controlling a steering machine, comprising the steps of:

-receiving electromagnetic signals emitted from one or more of a plurality of signal sources arranged in a predetermined area;

-processing the electromagnetic signals to identify a location of the signal source;

-determining a current position of a guiding machine with reference to said positioning of said signal source; and

-determining a path for the guiding machine to travel from the current position to a destination in the predetermined area.

2. The method of claim 1, wherein the electromagnetic signals are transmitted in orthogonal directions.

3. The method of claim 2, wherein the electromagnetic signal is transmitted in a linear polarization.

4. The method of claim 2, wherein each of the plurality of signal sources is arranged to emit electromagnetic signals in two orthogonal directions along a plane.

5. The method of claim 4, wherein the step of processing the electromagnetic signal comprises: the distance and direction of each signal source relative to the steering engine is determined based on the signal strength of each electromagnetic signal emitted by each signal source in two orthogonal directions.

6. The method of claim 4, wherein the step of receiving an electromagnetic signal comprises: receiving electromagnetic signals emitted from the plurality of signal sources by a plurality of antennas surrounding the director along the plane.

7. The method of claim 6, wherein the step of receiving an electromagnetic signal further comprises the steps of: sequentially receiving electromagnetic signals in each respective direction of the plurality of antennas in each detection interval.

8. The method of claim 1, further comprising the steps of:

-detecting an obstacle on the path; and

-determining an alternative path for the guiding machine to travel from the current position to the destination.

9. The method of claim 8, further comprising the steps of: notifying a user of the guidance machine of the detection of the obstacle.

10. The method of claim 1, further comprising the steps of: using a haptic signal, providing instructions to a user of the guidance machine related to traveling along the path.

11. The method of claim 10, wherein the haptic signal comprises a vibration signal having different vibration patterns, frequencies, and/or intensities.

12. A navigation system, comprising:

-a plurality of signal sources deployed in a predetermined area;

-a directing machine comprising a signal receiver arranged to receive electromagnetic signals emitted by one or more of said plurality of signal sources; and

-a processor arranged to process the electromagnetic signals to identify the location of the signal source and to thereby determine a current position of the guiding machine with reference to the location of the signal source; and the processor is further arranged to determine a path for the guiding machine to travel from the current location to a destination in the predetermined area.

13. The navigation system of claim 12, wherein the electromagnetic signals are transmitted in orthogonal directions.

14. The navigation system of claim 13, wherein the electromagnetic signal is transmitted in a linear polarization.

15. A navigation system as claimed in claim 13, wherein each of the plurality of signal sources is arranged to emit electromagnetic signals in two orthogonal directions along a plane.

16. A navigation system as claimed in claim 15, wherein the processor is arranged to determine the distance and direction of each signal source based on the signal strength of each electromagnetic signal emitted by each signal source in two orthogonal directions.

17. A navigation system as set forth in claim 15 wherein said director includes a plurality of antennas surrounding the director along the plane, said plurality of antennas being arranged to receive signals emanating from a plurality of signal sources.

18. A navigation system as claimed in claim 17, wherein the signal receiver is arranged to: sequentially receiving the electromagnetic signal in each respective direction of the plurality of antennas in each detection interval.

19. The navigation system of claim 17, wherein the plurality of antennas comprises a plurality of unidirectional antennas.

20. The navigation system of claim 17, wherein the plurality of antennas are electromagnetically separated so as to minimize mutual coupling between adjacent pairs of antennas.

21. The navigation system of claim 20, wherein the director further comprises an electromagnetic isolator disposed between each of the adjacent pairs of antennas.

22. The navigation system of claim 12, wherein the signal reader comprises a multi-channel RFID reader.

23. The navigation system of claim 12, wherein each of the plurality of signal sources comprises two orthogonally arranged RFID tags.

24. A navigation system as set forth in claim 12 wherein said guidance machine further comprises at least one sensor arranged to detect an obstacle on said path.

25. A navigation system as claimed in claim 24, wherein the processor is further arranged to: in response to detecting the obstacle, determining an alternate path for the guidance machine to travel from the current location to the destination.

26. The navigation system of claim 24, wherein the at least one sensor comprises at least one of an infrared sensor and an ultrasonic sensor.

27. A navigation system as claimed in claim 12, wherein the navigation machine further comprises a handle arranged to provide instructions relating to travel along the path to a user of the navigation machine using tactile signals.

28. A navigation system as set forth in claim 27 wherein said haptic signal comprises a vibration signal having different vibration modes, frequencies, and/or intensities.

29. A navigation system as claimed in claim 12, further comprising an input module arranged to receive input of the destination in the predetermined area.

30. The navigation system of claim 12, wherein the guidance machine comprises a robotic guided vehicle.