Aerial Haptic Feedback Technology Based On Ultrasonic Radiation Pressure

Tactile feedback provides a new way of interaction for human-computer interaction,and it is an important research direction in the field of human-computer interaction at this stage.The tactile feedback can be divided into contact tactile feedback and non-contact tactile feedback according to whether it is in direct contact with the device.In the study of non-contact haptic feedback,airborne tactile feedback based on ultrasonic radiation pressure is a hot topic at home and abroad.The aerial tactile feedback based on the ultrasonic radiation pressure frees the user from the constraints of the device,increases the naturalness of the interaction,and improves the comfort of the interaction.It can be widely used in education,medical treatment,games and other fields.In this paper,the aerial tactile feedback technology based on ultrasonic radiation pressure is studied from the aspects of ultrasonic focusing principle,software and hardware system development and system performance test.An aerial tactile feedback system based on ultrasonic radiation pressure is developed.The influence of carrier duty cycle and modulation wave frequency on tactile feedback performance is analyzed.It provides an experimental platform and related technical reference for the study of aerial tactile feedback technology based on ultrasonic radiation pressure.The main work of this paper is as follows:(1)The haptic feedback principle of ultrasonic radiation pressure and multi-channel ultrasonic focusing technology are studied.The design and development of 324-channel ultrasonic haptic feedback hardware system are completed,including 18×18 ultrasonic focusing array,multi-channel ultrasonic focusing driving unit,multi-channel focus main control unit based on DSP and FPGA dual-core structure and power supply and other circuits.(2)Construct DSP and FPGA dual-core software system based on oscillating feedback system of ultrasonic radiation pressure,complete FPGA design of main control unit DSP,main control unit FPGA and drive unit FPGA.The main control unit DSP performs functions such as phase calculation,uPP transmission,and host computer communication.The main control unit FPGA is responsible for generating synchronous clock,modulation signal,and synchronous transmission of serial phase information.The drive unit FPGA is responsible for completing the specific control of the phase of each channel based on the received control signals.In combination with the hardware system,the development of a tactile feedback system based on ultrasonic radiation pressure was completed.(3)On the basis of completing the haptic feedback system based on ultrasonic radiation pressure,the system performance is tested and analyzed from the aspects of power consumption,focus point size,duty cycle and modulation wave frequency to haptic feedback effect.Verify the effect of carrier duty cycle and modulation wave frequency on the rendering intensity of haptic feedback and the size of the rendered focus point.The main contributions and innovations of this paper include:(1)A complete prototype based on ultrasonic radiation pressure haptic feedback system was developed,which provided an experimental platform for further research on the aerial haptic feedback technology of subsequent ultrasonic radiation pressure.(2)Completion of DSP-based ultrasonic dynamic focusing algorithm,realizing moving point and multi-point ultrasonic focusing in 3D space;designing 324 channel phase control algorithm based on FPGA,which can realize synchronous phase control under high refresh frequency.The system phase delay accuracy is 0.5 microseconds and the focus point resolution is 17 mm.(3)The influence of carrier duty cycle and modulation wave frequency on the ultrasonic tactile feedback effect was tested and analyzed,and a simple graphical tactile rendering experiment in the air was carried out to verify the mapping relationship between the ultrasonic driving signal characteristics and the tactile feedback effect.Provides a reference for graphics rendering in 3D space.In this paper,the aerial tactile feedback technology based on ultrasonic radiation pressure is studied from basic theory,hardware system,software system and rendering experiment,which provides technical support for the in-depth study of aerial tactile feedback technology based on ultrasonic radiation pressure.