Non-contact haptic feedback system and method based on ultrasonic transducer array

Abstract

The invention discloses a non-contact haptic feedback system and method based on an ultrasonic transducer array. The non-contact haptic feedback system comprises the ultrasonic transducer array, an FPGA signal conversion and driving module and a data processing and control module arranged on a computer. The ultrasonic transducer array consists of a circuit board and a shell; the signal output end of the FPGA signal conversion and driving module is connected to a circuit board of the ultrasonic transducer array; and the data processing and control module is connected to the signal input end of the FPGA signal conversion and driving module. By designing the non-contact haptic feedback system which not only can realize non-contact touch, but also can realize real-time automatic adjustment of an ultrasonic focusing position, the problem that an ultrasonic focusing point in an existing non-contact haptic system cannot be automatically tracked and adjusted according to the change of a finger position is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of tactile feedback, and in particular to a non-contact force tactile feedback system and method based on an ultrasonic transducer array. Background Art

[0002] Ultrasonic phased array technology is a technology that uses an array of multiple ultrasonic transmitters and receivers to achieve focusing and directional emission of ultrasonic waves by controlling the phase and amplitude of each unit. Non-contact ultrasonic tactile feedback system is a human-computer interaction technology that has emerged in recent years. It uses ultrasonic phased array technology to provide tactile feedback to users without physical contact. The research on this technology aims to improve the naturalness, convenience and multi-sensory experience of human-computer interaction.

[0003] Existing ultrasonic tactile feedback systems can give fingers at a fixed height a sense of touch, but the system cannot obtain the movement of the finger and therefore cannot automatically adjust the ultrasonic focus position to track the direction of the finger movement. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art. To achieve the above purpose, a non-contact force tactile feedback system and method based on an ultrasonic transducer array is adopted to solve the problems raised in the above background technology.

[0005] A non-contact force tactile feedback system based on an ultrasonic transducer array, comprising an ultrasonic transducer array, an FPGA signal conversion and driving module, and a data processing and control module arranged on a computer;

[0006] The ultrasonic transducer array is composed of a circuit board and a housing;

[0007] The circuit board is provided with a plurality of array-distributed ultrasonic working array elements inside, the working array elements are composed of a plurality of ultrasonic sensor arrays, and are capable of transmitting and receiving ultrasonic waves;

[0008] The ultrasonic working array element includes a first ultrasonic transducer unit and a second ultrasonic transducer unit distributed around the first ultrasonic transducer unit. One ultrasonic transducer unit includes an ultrasonic sensor. The first ultrasonic transducer unit has the functions of ultrasonic emission and ultrasonic reception, and the second ultrasonic transducer unit only has the function of ultrasonic emission. The first ultrasonic transducer unit and the second ultrasonic transducer unit are both embedded with a sound source hole arranged on the shell.

[0009] The first ultrasonic transducer unit is located at the center of the ultrasonic working array element and is used to measure the distance from the skin surface to the center of the array element in real time;

[0010] The ultrasonic wave generated by the second ultrasonic transducer unit is used to form ultrasonic focus, which produces a non-contact tactile sensation when the skin contacts it, and uses a different operating frequency from that of the first ultrasonic transducer unit;

[0011] When the ultrasonic transducer array is working, all the first ultrasonic transducer units thereon work simultaneously to measure the skin distance above the unit, and the first ultrasonic transducer unit transmits the distance measurement information to the computer, and the computer uses the measured lowest point of the skin as the focal point for the second ultrasonic transducer unit to emit the ultrasonic wave; when the finger moves, the computer adjusts the parameters of the second ultrasonic transducer unit according to the distance measurement information to form a new focal position;

[0012] The signal output end of the FPGA signal conversion and driving module is connected to the circuit board of the ultrasonic transducer array;

[0013] The computer is connected to the signal input end of the FPGA signal conversion and driving module.

[0014] As a further technical solution of the present invention: the FPGA signal conversion and driving module is installed in an independent housing, and its two ends are connected to the ultrasonic transducer array and the computer.

[0015] As a further technical solution of the present invention: the data processing and control module arranged on the computer is used for performing system control and setting and adjusting ultrasonic parameters.

[0016] As a further technical solution of the present invention: the signal output end of the FPGA signal conversion and driving module and the ultrasonic transducer array are connected by wire.

[0017] As a further technical solution of the present invention: the computer provided with the data processing and control module is connected to the signal input end of the FPGA signal conversion and driving module by wireless connection or wired connection.

[0018] A technical solution in another aspect: A method for using a non-contact force tactile feedback system based on an ultrasonic transducer array as described in any one of the above, comprising the following steps:

[0019] Step S1, powering on and starting a non-contact force tactile feedback system based on an ultrasonic transducer array;

[0020] Step S2, initializing the data processing and control module and the FPGA signal conversion and driving module on the computer;

[0021] Step S3, inputting the frequency of the ultrasonic wave generated by the first ultrasonic transducer unit and the second ultrasonic transducer unit and the initial position of the focal point into the data processing and control module respectively;

[0022] Step S4, starting the ultrasonic transducer array, the ultrasonic transducer array generates ultrasonic waves according to the input parameters and forms an ultrasonic focus in a predetermined area;

[0023] Step S5: placing a finger or palm above the ultrasonic transducer array;

[0024] Step S6: The first ultrasonic transducer unit detects the finger and transmits the distance measurement information to the system, and the system adjusts the parameters of the second ultrasonic transducer unit to form a new focal point at the lowest point of the skin;

[0025] Step S7: the finger continues to pass through the focal point, and the computer determines that the finger has passed the ultrasonic focal point;

[0026] Step S8: The finger or palm moves, and the ultrasonic focus automatically follows the finger or palm to maintain a non-contact touch.

[0027] Compared with the prior art, the present invention has the following technical effects:

[0028] By adopting the above technical solution, a tactile feedback system is designed that can achieve non-contact touch, obtain finger position in real time and adjust the ultrasonic focus position. The system mainly includes an ultrasonic transducer array, an FPGA signal conversion and drive module, and a data processing and control module set on a computer. It can generate ultrasonic waves to form a focal point, and can also receive reflected ultrasonic waves to measure the distance of the finger above the ultrasonic transducer array in real time, thereby adjusting the ultrasonic focus position. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings:

[0030] Figure 1 A schematic diagram of the structure of a tactile feedback system according to an embodiment disclosed in the present application;

[0031] Figure 2 The structure diagram and plan view of the ultrasonic transducer array of the embodiment disclosed in the present application;

[0032] Figure 3 A plan view of a working array element on an ultrasonic transducer array according to an embodiment disclosed in the present application and a working schematic view of the working array element generating ultrasonic waves and receiving echoes;

[0033] Figure 4 This is a schematic diagram of focusing the ultrasonic waves generated by the ultrasonic transducer array according to the embodiment disclosed in the present application when in operation.

[0034] In the figure: 1. ultrasonic transducer array; 2. FPGA signal conversion and drive module; 3. computer; 4. working array elements on the ultrasonic transducer array; 5. internal circuit board of the ultrasonic transducer array; 6. sound source hole; 7. ultrasonic transducer array housing; 8. first ultrasonic transducer unit; 9. second ultrasonic transducer unit. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Please refer to Figure 1 , In an embodiment of the present invention, a non-contact force tactile feedback system based on an ultrasonic transducer array includes an ultrasonic transducer array 1, an FPGA signal conversion and driving module 2, and a computer 3, wherein a data processing and control module is disposed on the computer 3;

[0037] In this embodiment, the ultrasonic transducer array 1 is composed of a circuit board 5 and a housing 7 in terms of array structure, and the external features include a plurality of ultrasonic working array elements 4 distributed in an array.

[0038] In this embodiment, the FPGA signal conversion and driving module 2 is placed in an external independent square box, and the signal output end of the FPGA signal conversion and driving module 2 is connected to the ultrasonic transducer array 1 in a wired manner.

[0039] In this embodiment, the signal input end of the FPGA signal conversion and driving module 2 is connected to the computer 3 provided with a data processing and control program by wireless connection or wired connection.

[0040] In this embodiment, the data processing and control module on the computer 3 can be manually operated or automatically controlled to adjust the parameters of the ultrasonic transducer array 1 generating ultrasonic waves and the position of the focus point.

[0041] Please refer to Figure 2 In this embodiment, the ultrasonic transducer array 1 is structurally composed of a circuit board 5 and a shell 7. The circuit board 5 includes multiple sensors for transmitting and receiving ultrasonic waves. A plurality of array-distributed ultrasonic working array elements 4 are arranged on the circuit board 5. The 16 working array elements 4 are arranged symmetrically in 4 rows and 4 columns on the circuit board 5. The circuit board 5 is installed inside the shell 7 and is connected to the signal output end of the FPGA signal conversion and driving module 2.

[0042] In this embodiment, the upper plate of the shell 7 of the ultrasonic transducer array is provided with sound source holes 6, and the sound source holes 6 are also arranged on the upper plate of the shell in a symmetrical arrangement of 4 rows and 4 columns. The ultrasonic working array element 4 on the internal circuit board includes a first ultrasonic transducer unit and a second ultrasonic transducer unit distributed in an array manner around the first ultrasonic transducer unit. The number of sound source holes is the same as that of the ultrasonic transducer unit, and each sound source hole 6 corresponds to a first ultrasonic transducer unit or a second ultrasonic transducer unit, and the sound source hole and the ultrasonic transducer unit are embedded together.

[0043] Please refer to Figure 3 A working array element 4 on the ultrasonic transducer array is composed of 9 ultrasonic transducer units, which are symmetrically arranged in 3 rows and 3 columns. The working array element includes two types of ultrasonic transducer units, and each ultrasonic transducer unit includes an ultrasonic sensor; the first ultrasonic transducer unit 8 contains an ultrasonic transmitter and a receiver, which can transmit and receive ultrasonic waves and is located at the center of the working array element; the second ultrasonic transducer unit 9 can only transmit ultrasonic waves for focusing and is evenly distributed around the first ultrasonic transducer unit 8.

[0044] In this embodiment, the first ultrasonic transducer unit 8 and the second ultrasonic transducer unit 9 are both arranged on a circuit board inside the ultrasonic transducer array. The first ultrasonic transducer unit 8 transmits and receives ultrasonic waves for real-time measurement of the distance from the skin surface to the center of the array element.

[0045] In this embodiment, the second ultrasonic transducer unit 9 around the center of the array element emits ultrasonic waves, focusing on a certain position above the ultrasonic transducer array 1, producing a non-contact touch when the skin touches it, and adopts a different operating frequency from the first ultrasonic transducer unit.

[0046] In this embodiment, the first ultrasonic transducer unit can transmit and receive ultrasonic waves and is insensitive to the ultrasonic frequency transmitted by the second ultrasonic transducer unit;

[0047] The second ultrasonic transducer unit only transmits ultrasonic waves, does not receive ultrasonic echoes, and uses a different operating frequency from the first ultrasonic transducer unit;

[0048] Please refer to Figure 4, the ultrasonic transducer uses phased array technology, and the ultrasonic waves emitted by each second ultrasonic transducer unit can be set to have the same phase when they reach the touch point, thereby achieving superposition of ultrasonic waves at the touch point. When the ultrasonic transducer array is working, all the first ultrasonic transducer units on it work at the same time, measuring the skin distance above the unit. The first ultrasonic transducer unit transmits the ranging information to the computer, and the computer uses the measured lowest point of the skin as the focal point for the second ultrasonic transducer unit to emit ultrasonic waves; when the finger moves, the computer adjusts the parameters of the second ultrasonic transducer unit according to the ranging information to form a new focal position. The use of phased array technology enhances the signal at the touch point and enhances the sense of touch;

[0049] Working principle:

[0050] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a tactile feedback system according to an embodiment disclosed in the present application;

[0051] The working principle of the ultrasonic tactile feedback system is based on the emission and reception of ultrasonic waves, the conversion of electrical signals, and the phase setting. First, the parameters for the first ultrasonic transducer unit and the second ultrasonic transducer unit to generate and transmit ultrasonic waves are set on the data processing and control module on the computer 3. These parameters define the frequency of the ultrasonic transducer unit generating ultrasonic waves and the coordinate parameters of the second ultrasonic transducer unit transmitting ultrasonic waves to form the initial focus point. After the ultrasonic transducer array is started, the computer 3 transmits the parameter information to the FPGA signal conversion and drive module 2. The FPGA signal conversion and drive module 2 converts the parameter information into a driving signal for the sensor in the ultrasonic transducer unit to generate and transmit ultrasonic waves. These signals include phase period, synchronous clock, and modulation signal. The FPGA signal conversion and drive module 2 transmits the driving signal to the circuit board inside the ultrasonic transducer array 1. The driving signal is amplified and accurately output through the circuit board to ensure that each working array element on the circuit board can work according to the predetermined requirements.

[0052] The ultrasonic sensor of the second ultrasonic transducer unit on the circuit board receives the driving signal transmitted by the circuit board, generates ultrasonic waves according to predetermined parameters and forms a focus in a specific area; the first ultrasonic transducer unit receives the driving signal to emit ultrasonic waves and also receives the ultrasonic echo reflected by the skin surface. The received echo signal is transmitted to the FPGA signal conversion and driving module 2 through the internal circuit board of the ultrasonic transducer array, and then transmitted to the data processing and control module on the computer 3 after being processed by the FPGA signal conversion and driving module 2. When a person's finger or palm is placed above the ultrasonic transducer array, the first ultrasonic transducer unit detects the finger and transmits the ranging information to the system, and the system adjusts the parameters of the second ultrasonic transducer unit to form a focus point at the lowest point of the skin; when the finger or palm moves, the computer adjusts the position of the focus point by detecting the finger position in real time.

[0053] A technical solution in another aspect: A method for using a non-contact force tactile feedback system based on an ultrasonic transducer array as described in any one of the above, comprising the following steps:

[0054] Step S1, powering on and starting a non-contact force tactile feedback system based on an ultrasonic transducer array;

[0055] Step S2, initializing the data processing and control module and the FPGA signal conversion and driving module on the computer;

[0056] Step S3, inputting the frequency of the ultrasonic wave generated by the first ultrasonic transducer unit and the second ultrasonic transducer unit and the initial position of the focal point into the data processing and control module respectively;

[0057] Step S4, starting the ultrasonic transducer array, the ultrasonic transducer array generates ultrasonic waves according to the input parameters and forms an ultrasonic focus in a predetermined area;

[0058] Step S5: placing a finger or palm above the ultrasonic transducer array;

[0059] Step S6: The first ultrasonic transducer unit detects the finger and transmits the distance measurement information to the system, and the system adjusts the parameters of the second ultrasonic transducer unit to form a new focal point at the lowest point of the skin;

[0060] Step S7: the finger continues to pass through the focal point, and the computer determines that the finger has passed the ultrasonic focal point;

[0061] Step S8: The finger or palm moves, and the ultrasonic focus automatically follows the finger or palm to maintain a non-contact touch.

[0062] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents, and all should be included within the scope of protection of the present invention.

Claims

1. A non-contact force tactile feedback system based on an ultrasonic transducer array, characterized in that: It includes an ultrasonic transducer array, an FPGA signal conversion and driving module, and a data processing and control module arranged on a computer; The ultrasonic transducer array is composed of a circuit board and a housing; The circuit board is provided with a plurality of array-distributed ultrasonic working array elements inside, the working array elements are composed of a plurality of ultrasonic sensor arrays, and are capable of transmitting and receiving ultrasonic waves; The ultrasonic working array element includes a first ultrasonic transducer unit and a second ultrasonic transducer unit distributed around the first ultrasonic transducer unit. One ultrasonic transducer unit includes an ultrasonic sensor. The first ultrasonic transducer unit has the functions of ultrasonic emission and ultrasonic reception, and the second ultrasonic transducer unit only has the function of ultrasonic emission. The first ultrasonic transducer unit and the second ultrasonic transducer unit are both embedded with a sound source hole arranged on the shell. The first ultrasonic transducer unit is located at the center of the ultrasonic working array element and is used to measure the distance from the skin surface to the center of the array element in real time; The ultrasonic wave generated by the second ultrasonic transducer unit is used to form ultrasonic focus, which produces a non-contact tactile sensation when the skin contacts it, and uses a different operating frequency from that of the first ultrasonic transducer unit; When the ultrasonic transducer array is working, all the first ultrasonic transducer units thereon work simultaneously to measure the skin distance above the unit, and the first ultrasonic transducer unit transmits the distance measurement information to the computer, and the computer uses the measured lowest point of the skin as the focal point for the second ultrasonic transducer unit to emit the ultrasonic wave; when the finger moves, the computer adjusts the parameters of the second ultrasonic transducer unit according to the distance measurement information to form a new focal position; The signal output end of the FPGA signal conversion and driving module is connected to the circuit board of the ultrasonic transducer array; The computer is connected to the signal input end of the FPGA signal conversion and driving module.

2. The non-contact force tactile feedback system based on an ultrasonic transducer array according to claim 1, characterized in that: The FPGA signal conversion and driving module is installed in an independent housing, and its two ends are connected to the ultrasonic transducer array and the computer.

3. The non-contact force tactile feedback system based on ultrasonic transducer array according to claim 1, characterized in that: The data processing and control module arranged on the computer is used for performing system control and setting and adjusting ultrasonic parameters.

4. The non-contact force tactile feedback system based on ultrasonic transducer array according to claim 1, characterized in that: The signal output end of the FPGA signal conversion and driving module and the ultrasonic transducer array are connected by wire.

5. The non-contact force tactile feedback system based on ultrasonic transducer array according to claim 4, characterized in that: The computer provided with the data processing and control module is connected to the signal input end of the FPGA signal conversion and driving module by wireless connection or wired connection.

6. A method using a non-contact force tactile feedback system based on an ultrasonic transducer array as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1, powering on and starting a non-contact force tactile feedback system based on an ultrasonic transducer array; Step S2, initializing the data processing and control module and the FPGA signal conversion and driving module on the computer; Step S3, inputting the frequency of the ultrasonic wave generated by the first ultrasonic transducer unit and the second ultrasonic transducer unit and the initial position of the focal point into the data processing and control module respectively; Step S4, starting the ultrasonic transducer array, the ultrasonic transducer array generates ultrasonic waves according to the input parameters and forms an ultrasonic focus in a predetermined area; Step S5: placing a finger or palm above the ultrasonic transducer array; Step S6: The first ultrasonic transducer unit detects the finger and transmits the distance measurement information to the system, and the system adjusts the parameters of the second ultrasonic transducer unit to form a new focal point at the lowest point of the skin; Step S7: the finger continues to pass through the focus point, and the computer determines that the finger has passed the ultrasonic focus point; Step S8: The finger or palm moves, and the ultrasonic focus automatically follows the finger or palm to maintain a non-contact touch.

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