In this research, modeling, and analysis of a beam-type touch screen interface with multiple actuators is considered. A mechanical model of a touch screen system, as thin beams, is developed with embedded electrostatic actuators at different spatial locations. This discrete finite element-based model is developed to compute the analytical and numerical vibrotactile response due to multiple actuators excited with varying frequency and amplitude. The model is tested with spring-damper boundary conditions incorporating sinusoidal excitations in the human haptic range. An analytical solution is proposed to obtain the vibrotactile response of the touch surface for different frequencies of excitations, number of actuators, actuator stiffness, and actuator positions. The effect of the mechanical properties of the touch surface on vibrotactile feedback provided to the user feedback is explored. Investigation of optimal location and number of actuators for a desired localized response, such as the magnitude of acceleration and variation in acceleration response for a desired zone on the interface, is carried out. It has been shown that a wide variety of localizable vibrotactile feedback can be generated on the touch surface using different frequencies of excitations, different actuator stiffness, number of actuators, and actuator positions. Having a mechanical model will facilitate simulation studies capable of incorporating more testing scenarios that may not be feasible to physically test.

No abstract

No abstract

No abstract

No abstract

The design of introduces a multi-mode transmulti-plexer (TMUX) structure capable of generating a great set of user-bandwidths and center frequencies. The structure utilizes fixed integer sampling rate conversion (SRC) blocks, Farrow-based variable interpolation and decimation structures, and variable frequency shifters. A main advantage of this TMUX is that it needs only one filter design beforehand. Specifically, the filters in the fixed integer SRC blocks as well as the subfilters of the Farrow structure are designed only once. Then, all possible combinations of bandwidths and center frequencies are obtained by p r o p e r l y a d j u s t i n g t h e variable d e l a y p a r a m e t e r of t h e Farrowbased filters and the variable parameters of the frequency shifters. The paper includes examples for demonstration.It also shows that, using the rational SRC equivalent of the Farrow-based filters, the TMUX can be described in terms of conventional multirate building blocks which may be u sef ul in further analysis of the overall system.

Touch screen devices have become ubiquitous in modern day-to-day lives. While smaller touchscreen devices provide enough user engagement with meaningful haptic feedback, large touch devices still lack meaningful haptic stimulation. Existing literature for large touch surface vibrotactile localization uses many actuators and conventional boundary conditions. Previous numerical studies on haptic localization do not address multi-frequency excitation. This research proposes a new spring-damper boundary condition for a large bar-type display. Subsequently, a mechanical model of the large touch bar surface with multipleelectrostatic vibration actuators is developed using material damping information with multi-frequency excitation. Simultaneously, an experimental setup is developed for validation of the developed model. An optimization technique to localize vibrotactile haptic rendering at multiple selected zones of the touch bar is proposed. It has been established that by varying frequencies of excitation of two electrostatic resonant actuators, localizable vibrotactile feedback can be generated across the length of the touch bar. The experimental results corroborate the simulation results. Finally, the proposed optimization strategy for multi-zone vibrotactile rendering is experimentally verified.

In various embedded system applications, the high speed multi-serial communication is necessary. Various embedded systems require DSP (Digital Signal Processing) to process information & FPGA to control the peripheral devices. UART (Universal Asynchronous Receive Transmit) is designed in FPGA & connected to DSP so as to meet the real time capability of system along with compact, stable & reliable data transmission. In this paper we propose a softwareimplementation technique of an UART to get a platform independent UART-core for high speed serial communication in FPGA. Here the core is written in Verilog & implemented using XILINX ISE.