Slime mould tactile sensor

Slime mould P. polycephalum is a single cells visible by unaided eye. The cells shows a wide spectrum of intelligent behaviour. By interpreting the behaviour in terms of computation one can make a slime mould based computing device. The Physarum computers are capable to solve a range of tasks of computational geometry, optimisation and logic. Physarum computers designed so far lack of localised inputs. Commonly used inputs --- illumination and chemo-attractants and -repellents --- usually act on extended domains of the slime mould's body. Aiming to design massive-parallel tactile inputs for slime mould computers we analyse a temporal dynamic of P. polycephalum's electrical response to tactile stimulation. In experimental laboratory studies we discover how the Physarum responds to application and removal of a local mechanical pressure with electrical potential impulses and changes in its electrical potential oscillation patterns

Optical fiber tactile sensor

A tactile sensor comprises an array of cells which are covered by an elastic membrane, having an exposed surface which is adapted to come in contact with an object. Light is conducted to each cell from a light source by an optical fiber which terminates at the cell. Reflected light from the cell is conducted by an optical fiber to a light processor, which senses changes in the light received thereby from an ambient level whenever an object comes in contact with the membrane surface above the cell

Current Trend of Tactile Sensor in Advanced Applications

Tactile sensor is one of the important tactile technologies which discovered in the 1980s. It grows in line with development of robotics and computers. From current development trends, varieties of application areas from tactile sensor have been proposed. In this paper, developments of tactile sensor have been reviewed and the applications from previous five years journals are discussed. The transduction techniques, their relative advantages and disadvantages, latest application area of tactile sensor and contribution are analyzed

Development Of Finger Type Tactile Sensor With Surface Roughness Analysis

This research is focused on the development of finger type tactile sensor with surface roughness analysis.Among various human sensations like hearing,sight,taste and smell,touch is a critical co-existing sensation required to interact with surrounding environment.Therefore,it is believed that a good understanding between the touch and surface roughness have potential benefits to the performance of the finger type tactile sensor robot.Even though there is a lot of tactile sensor’s type used in robotic application but there is much less on work has been done on load cell.As far as it is concerned,tactile sensor,vison and audio system is very expensive. Therefore,something cheaper which is load cell is used as a replace for other expensive tactile sensor,in order to modelling and develop a finger type tactile sensor.So,a knowledge study regarding on tactile sensor,touch and grasping are investigated in order to proceed the research.Next,the finger type tactile sensor is designed and developed in SolidWorks software for visual-aided all the view of prototype.To achieve the sensory performance and function of the human fingertips,the design of the fingertips sensor mimics the human fingertips in many aspects,including its size and shape.As objects slide across the structure of surface roughness of the finger type tactile sensor,it generates force that measure in ADC (Volt) that are detected by a loadcells inside the holder.By using Graphical User Interface (GUI),data logging for every extracted graph of each experiment is performed.The developed finger type tactile sensor needs to be tested in order to identify the performance capability of the sensor according to the designed function.A set of 3D printed objects with different values of roughness has been prepared as the sample for this test.Then,for performance validation,Experiment 1: Calibration (Mitutoyo Precision Reference Specimen) has been conducted between using manual robot (Z-arm) and auto robot (Comau Robot).Comau Robot has been chosen as the most suitable robot for the rest of the experiments, then the work is extended to Experiment 2 (Test using Needle File) and Experiment 3 (Test using Tile).The experiment results show that the functionality of the finger type tactile sensor has been successfully validated and proven acceptable for all set of experiment

Real-time edge tracking using a tactile sensor

Object recognition through the use of input from multiple sensors is an important aspect of an autonomous manipulation system. In tactile object recognition, it is necessary to determine the location and orientation of object edges and surfaces. A controller is proposed that utilizes a tactile sensor in the feedback loop of a manipulator to track along edges. In the control system, the data from the tactile sensor is first processed to find edges. The parameters of these edges are then used to generate a control signal to a hybrid controller. Theory is presented for tactile edge detection and an edge tracking controller. In addition, experimental verification of the edge tracking controller is presented

A dynamic tactile sensor on photoelastic effect

Certain photoelastic materials exhibit birefringent characteristics at a very low level of strain. This property of material may be suitable for dynamic or wave propagation studies, which can be exploited for designing tactile sensors. This paper presents the design, construction and testing of a novel dynamic sensor based on photoelastic effect, which is capable of detecting object slip as well as providing normal force information. The paper investigates the mechanics of object slip, and develops an approximate model of the sensor. This allows visualization of various parameters involved in the sensor design. The model also explains design improvements necessary to obtain continuous signal during object slip. The developed sensor has been compared with other existing sensors and experimental results from the sensor have been discussed. The sensor is calibrated for normal force which is in addition to the dynamic signal that it provides from the same contact location. The sensor has a simple design and is of a small size allowing it to be incorporated into robotic fingers, and it provides output signals which are largely unaffected by external disturbances

Artificial Roughness Encoding with a Bio-inspired MEMS- based Tactile Sensor Array

A compliant 2×2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad