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This paper aims to report a flexible position-sensitive sensor that can be applied as large-area electronic skin over the stiff media.

The sensor uses a whole piezoresistive film as a touch sensing area. By alternately constructing two uniform electric fields with orthogonal directions in the piezoresistive film, the local changes in conductivity caused by touch can be projected to the boundary along the equipotential line under the constraint of electric field. Based on the change of boundary potential in the two uniform electric fields, it can be easy to determine the position of the contact area in the piezoresistive film.

Experiment results show the proposed tactile sensor is capable of detecting the contact position and classifying the contact force in real-time based on the changes of the potential differences on the boundary of the sensor.

The application example of using the sensor sample as a controller in shooting game is presented in this paper. It shows that the sensor has excellent touch sensing performance.

In this paper, a position-sensitive electronic skin is proposed. The experiment results show that the sensor has great application prospects in the field of interactive tactile sensing.

Vibration measurement is needed in many industrial production processes, such as equipment monitoring, fault diagnosis, and noise analysis and eliminating and so on. The purpose of this paper is to propose a simple vibration testing system which includes the laser, the string, position sensitive detector (PSD) and the corresponding signal processing circuit.

PSD is an optical semiconductor sensor that can fast locate the luminous spot position precisely, which means that it can output different electric current according to the luminous spot at different position of its surface. Moreover, the experiment on PSD sensor using different vibration source and frequency had been carried out. Finally, the vibration waveform of the luminous spot on PSD photosurface was obtained.

According to the experimental results, each kind of vibration parameter with different vibration source, such as vibration frequency and amplitude can be calculated.

The experimental results agreed with the actual parameter, which showed PSD not only had its own good qualities in the position measurement, but also had the unique superiority in the vibration measurement.

The purpose of this paper is to achieve the trajectory tracking measurement of a moving target based on double position sensitive detectors (PSDs).

In this paper, first, a double PSD-based measurement system including hardware system and software system is built up. Then, the working principle is studied to calculate parameters, and calibration experience is conducted. Finally, this double PSD-based measurement system is used to test angular displacement and axial displacement on the tool magazine and automatic tool changer.

In the experiment, the maximum position error of a space point based on double PSD measurement system is 0.8566 mm, and the average error is 0.4716 mm. These results show that the built double PSD-based measurement system of trajectory tracking of a moving target is reasonable.

Combining the characteristics of the PSD and principles of binocular visual measurement, a non-contact three-dimensional measuring system based on double PSDs is developed. The designed double-based measurement system is quite suitable for measurement of a fast-changing illuminant or in the case that the tracking accuracy is not tight.

Vision sensor for arc weld seam tracking uses a projected line of light scan from a high power infrared LED, which is detected by a two‐dimensional position‐sensitive photocell. It is compact enough to be mounted on a robot hand and works well on surfaces of poor reflectivity.

The purpose of this paper is to solve the problem that the analytic solution model of spatial three-dimensional coordinate measuring system based on dual-position sensitive detector (PSD) is complex and its precision is not high.

A new three-dimensional coordinate measurement algorithm by optimizing back propagation (BP) neural network based on genetic algorithm (GA) is proposed. The mapping relation between three-dimensional coordinates of space points in the world coordinate system and light spot coordinates formed on dual-PSD has been built and applied to the prediction of three-dimensional coordinates of space points.

The average measurement error of three-dimensional coordinates of space points at three-dimensional coordinate measuring system based on dual-PSD based on GA-BP neural network is relatively small. This method does not require considering the lens distortion and the non-linearity of PSD. It has simple structure and high precision and is suitable for three-dimensional coordinate measurement of space points.

A new three-dimensional coordinate measurement algorithm by optimizing BP neural network based on GA is proposed to predict three-dimensional coordinates of space points formed on three-dimensional coordinate measuring system based on dual-PSD.

Screen‐printing is an appropriate technique for the manufacture of large‐area position‐sensitive detectors. The purpose of this paper is to present simple methods of paste preparation and appropriate processing of thick films.

Active layers of photoconductive cells based on doped CdS_0.32Se_0.68 were prepared by screen‐printing and sintering at 530°C. A sulfide‐selenide mixture or a mixed crystal material and propylene glycol (PG) was deposited as a paste. PG served as the temporary paste binder. Cadmium chloride was used as a fluxing agent and a donor source. Copper(II) chloride was used as an acceptor source. The effect of the paste composition and sintering time on the resistance and slope of the resistance vs illumination dependence of cells was investigated. These parameters were checked again after eight years of cell storage.

The cell properties are considerably influenced by the time periods between printing, drying, and sintering. Addition of 2.3 mg Cu^2 +and 17 mg Cl⁻ per 1 g of mixed crystal CdS_0.32Se_0.68 enables the preparation of photoconductive cells with the slope higher than 1.2 and a very good long‐term stability of cell parameters.

The effect of the cell parameters' dependence on the paste, age and the time between printing and sintering rendered it impossible to make a more detailed examination after eight‐year storage of samples.

The paper is of value in showing that in the prepared cells exhibit high slopes of resistance‐illumination dependence. The high slope enables detection of laser pulses using only simple filtration of ambient illumination. The changes in photoconductive cell properties after eight‐year storage are presented.

The industrial robot has high repeatability but low accuracy. With the industrial robot being widely used in complicated tasks, e.g. arc welding, offline programming and surgery, accuracy of the robot is more and more important. Robot calibration is an efficient way to improve the accuracy. Previous methods such as using coordinate measurement machines, laser trackers or cameras are limited by the cost, complex operation or the resolution. The purpose of this paper is to propose an approach and calibration equipment to address these issues.

The proposed method relies mainly upon a laser pointer attached on the end‐effector and single position‐sensitive devices (PSD) arbitrarily located on the workcell. The automated calibration procedure (about three minutes) involves aiming the laser lines loaded by the robot towards the center of the PSD surface from various robot positions and orientations. The localization is guaranteed by precise PSD feedback servoing control, which means physically the intersections of each pair of laser lines (virtual lines) are on the same point. Based on the untouched single‐point constraint, the robot joint offset calibration is implemented. Using the authors' proposed approach, a portable, low‐cost, battery‐powered, wireless and automated calibration system was implemented. Error analysis was conducted on the system.

The localization error of the developed calibration system is within 2 μm. The errors in joint space are magnified in PSD plane, and consequently the resolution in the joint space is improved. The standard deviation of the identified parameters was small (10‐2), indicating the stability of the calibration method. Both simulation and experimental results verify the feasibility of the proposed method and demonstrate the developed calibration system can identify joint offset with uncalibrated laser tool parameters.

The paper shows how a portable calibration system for joint offset of industrial robots was developed and how the goal of fast, automated, low‐cost, portable, and high precision calibration methods for joint offset was achieved.

The purpose of this paper is to propose a sensor system and its measuring strategy. The proposed system is regarded as a total system of a robot and a sensor. It can make full use of a robot's degrees of freedom (DOF) for not only locomotion but also sensing.

The sensor system is composed of a connected crawler robot and a simple sensor unit. The connected crawler robot consists of five connected flat crawler stages; each stage has motor‐driven crawlers on its left and right side. The left and right crawlers are driven by motors independently. The five stages are connected by motor‐driven joints, which can be arbitrarily controlled. The sensor unit is made up of a position sensitive detector and two active joints. Generally, all sensors have a measurable range limit. If the object is bigger than the measurable range, it is impossible to recognize the object's shape. However, this sensor system compensates for this problem due to a combination of sensor unit's motion and robot's motion. The robot's DOF are ordinarily used for going forward. In this moving, if the sensor detects a bigger object than its measurable range, the robot's DOF are used for lifting up sensor unit. Therefore, the robot's DOF are exploited for both locomotion and scanning.

The experiment was done by using proposed measurement strategies. Through this experiment, the maximum distance error was 0.037 m, that fulfils the required sensor's accuracy. This experiment confirmed that the measurable range was expanded by making full use of the robot's DOF and sensor's DOF. The robot's DOF which is ordinarily used for moving is applicable to expand measurable range. Therefore, it was possible to expand measurable range by making full use of the robot's DOF without mounting extra equipments or mechanism on the robot. Hence, it was enable to exert enough sensing function even if the sensor's structures and robot's structure are also simple, by using both the robot and the sensor's functions effectively and simultaneously.

General existing mobile robot systems have both mobile function and sensing function, they are completely separate. However, this sensor system is regarded as a total system of robot and sensor. It can make full use of a robot's DOF for not only locomotion but also sensing. This sensor system makes full use of a robot's DOF. Hence, it is enable to exert enough sensing function even if the sensor's structure and robot's structure are also simple. There is originality on this point.

The purpose of this paper is to analyze the measurement error of a three-dimensional coordinate measurement system based on dual-position-sensitive detector (PSD) under different background light.

The mind evolutionary algorithm (MEA)-back propagation (BP) neural network is used to predict the three-dimensional coordinates of the points, and the influence of the background light on the measurement accuracy of the three-dimensional coordinates based on PSD is obtained.

The influence of the background light on the measurement accuracy of the system is quantitatively calculated. The background light has a significant influence on the prediction accuracy of the three-dimensional coordinate measurement system. The optical method, electrical method and photoelectric compensation method are proposed to improve the measurement accuracy.

BP neural network based on MEA is applied to the coordinate prediction of the three-dimensional coordinate measurement system based on dual-PSD, and the influence of background light on the measurement accuracy is quantitatively analyzed.

Looks at the use of non‐contact displacement and vibration sensors and notes their value for difficult sensing measurements. Mentions various situations which may dictate the use of a non‐contact sensor. Focuses on fibre‐optic sensors and laser triangulation sensors. Concludes that practical uses for such devices are rapidly expanding.