Abstract: A solder composition includes about 20% to about 25% by weight tin, about 0.03% to about 3% by weight nickel, about 66% to about 75% by weight indium, and about 0.5% to about 2% by weight silver. The solder composition can further include about 0.1% to about 8% by weight antimony, about 0.03% to about 4% by weight copper, about 0.2% to about 6% by weight zinc, and/or about 0.01% to about 0.3% by weight germanium. The solder composition can be used to solder an electrical connector to an electrical contact surface on a glass component.

Abstract: Provided is a flux which can remove metal oxides to improve solder wettability and can fix the object to be soldered with flux residue. The flux contains thermosetting resin, and long-chain dibasic acid mixture including one or more species of first long-chain dibasic acid having an alkyl group in a side chain, the first long-chain dibasic acid being added as a hardening agent for hardening the thermosetting resin and an activator, and second long-chain dibasic acid having an alkyl group and an alkoxycarbonyl group in a side chain and having carbon number of 8 or more in a main chain between the carboxyl groups at opposite terminals. It is preferable that content of the thermosetting resin is 30% through 70% and content of the long-chain dibasic acid mixture is 20% through 60%.

Abstract: A bolt tensioning assembly includes a bolt having a through-hole extending longitudinally through the bolt. A ram is inserted into the through-hole. A top cap is configured to be attached to a first end portion of the bolt. A load distributing member is configured to engage the ram at a location adjacent a second end portion of the bolt to distribute a force exerted thereon by the ram, and an actuator is connected to the top cap to exert a force on the ram to cause the ram to engage the load distributing member such that the bolt is placed under tensile stress.

Abstract: Disclosed generally is a face plate for a vise that is capable of gripping multiple work-pieces of different sizes at the same time. In one embodiment, the disclosed subject matter may be a vise face plate comprising: a base with an upper compensation structure and a lower compensation structure; and, wherein the upper and lower compensation structures define two sets of working surfaces. In use, the plate may be secured to a movable jaw so that the working surfaces may be employed to clamp a plurality of work pieces between the working surfaces and a fixed jaw.

Abstract: A tool changer is composed of a support shaft, a forward/backward movement drive motor moving the support shaft upward and downward, a rotation drive motor rotating the support shaft about an axis, a tool change arm having tool grippers formed at both ends thereof, and an air blow mechanism discharging compressed air to a tool and a next tool gripped by the tool grippers. In tool change using this tool changer, in a positioning operation, the tool change arm is rotated by degrees and compressed air is discharged toward the tool and the next tool by the air blow mechanism.

Abstract: A two-layer disk type tool magazine device matched with a numerical control machine tool, comprises a tool magazine base, a tool magazine support, tool sleeve chucks, a tool disk base, tool sleeves and a tool alignment instrument. The tool magazine base is connected to and installed on the machine tool. The tool magazine support is connected to one end of the tool magazine base. The tool disk base is connected to the support by means of a bolt. The tool alignment instrument is installed at the other end of the tool magazine base. The two tool sleeve chucks are installed on the tool disk base and partitioned by a tool disk partition sleeve. The two layers of tool sleeve chucks clamp a tool sleeve base and are fixed by means of bolts. A tool disk pressing ring presses against the tool sleeve chuck on the upper layer.

Abstract: A centering mechanism for retaining an object, wherein the centering mechanism has a locking mechanism, having at least a first tangential surface. Furthermore, the centering mechanism can be used in conjunction with a mechanism for retaining an electronic device or an electronic device in a case. The structure of the centering mechanism and the locking mechanism allows for the locking mechanism to further actuate and lock the centering mechanism, such that an object retained therein is secured and aligned.

Abstract: A machine tool with a chip evacuation device according to the present invention is provided with a cleaning mechanism for cleaning a part or the whole of the chip evacuation device and a control unit configured to control respective operations of the chip evacuation device and the cleaning mechanism in association with each other. By using an electric motor, such as a synchronous motor capable of position control, as a power source for the chip evacuation device, the respective operations of the chip evacuation device and the cleaning mechanism can be associated with each other to effectively clean the chip evacuation device.

Abstract: Woodworking machines and safety methods for use with those machines are disclosed. The machines include a detection system adapted to detect one or more dangerous conditions and a reaction system associated with the detection system. The reaction system can include an explosive to trigger the system, and also can be configured to retract a cutting tool at least partially away from a cutting region upon detection of a dangerous condition by the detection system.

Abstract: A pneumatic tool comprises a housing, a chamber formed inside the housing, and a pneumatic mechanism and a cylinder disposed inside the chamber. The housing includes a gas inhale channel and a gas exhaust channel respectively interconnecting with the chamber. A ventilation gap is formed between the cylinder and chamber. The cylinder includes a compartment receiving the pneumatic mechanism, a gas inlet hole interconnecting with the compartment and gas inhale channel, and at least one gas outlet hole interconnecting with the compartment and ventilation gap. The pneumatic tool also comprises at least one buffer turbulent channel disposed on at least one of the sides of the cylinder and chamber, which face the ventilation gap. The variation of the cross section area between the ventilation gap and buffer turbulent channel can regulate flowing the speed of the high-pressure and high-speed gas and make it drive the pneumatic mechanism smooth.

Abstract: An angle grinder control system including an angle grinder control assembly. The angle grinder control assembly includes an outer-shell, a tightening-rod, an inner-shell, a control-rod, a return-spring, a trigger, and a control-rod-pin. The outer-shell includes a first-half-body-section and a second-half-body-section, where the inner-shell includes a primary-half-body-section and a secondary-half-body-section. The angle grinder control system provides a user an alternate means for controlling an angle-grinder-on/off-switch such that the angle grinder control system provides for safe use of an angle grinder in relation to the user. Embodiments of an angle grinder control system may include vents to promote cooling of the angle grinder. Additional embodiments many include a handle to aid the user in controlling and manipulating the angle grinder.

Abstract: A honing method for machining the inner surface of a bore in a workpiece via at least one honing operation using an expandable honing tool with an annular cutting group. The method includes coupling of the honing tool to a working spindle of a machine tool, and; inserting the honing tool into an inlet of the bore with the cutting material elements retracted, until it is in a final insertion position, in which the cutting group is located in an end region of the bore. Then the honing tool is turned and the annular cutting group is simultaneously expanded to create a cylindrical widening of the bore, followed by withdrawal of the honing tool from the bore with simultaneous turning of the honing tool in such a way that the bore is successively further widened in the direction of the inlet side.

Abstract: A polishing system configured to polish a lap includes a lap configured to contact a workpiece for polishing the workpiece; and a septum configured to contact the lap. The septum has an aperture formed therein. The radius of the aperture and radius the workpiece are substantially the same. The aperture and the workpiece have centers disposed at substantially the same radial distance from a center of the lap. The aperture is disposed along a first radial direction from the center of the lap, and the workpiece is disposed along a second radial direction from the center of the lap. The first and second radial directions may be opposite directions.

Abstract: A polisher includes a wafer carrier, a polishing head, a movement mechanism, and a rotation mechanism. The wafer carrier has a supporting surface. The supporting surface is configured to carry a wafer thereon. The polishing head is present above the wafer carrier. The polishing head has a polishing surface. The polishing surface of the polishing head is smaller than the supporting surface of the wafer carrier. The movement mechanism is configured to move the polishing head relative to the wafer carrier. The rotation mechanism is configured to rotate the polishing head relative to the wafer carrier.

Abstract: The method of the present invention comprises the steps of: previously obtaining correlation data between surface properties of the polishing pad dressed under a plurality of stages of dressing conditions and polishing effects of the work polished by the polishing pad dressed under the dressing conditions; determining an assumed dressing condition capable of achieving an object polishing effect from the correlation data; dressing the polishing pad under the assumed dressing condition determined; polishing the work; cleaning the polishing pad which has been used for polishing the work; and measuring a surface property of the cleaned polishing pad.

Abstract: Automatic handling apparatus having a suction-head sucking and holding a workpiece, an arm is connected to and moves the suction-head, and a stage on which the workpiece to be carried to the carrier holding hole is mounted, the suction-head has a movable section which is movable within a parallel plane to the suction-head body, the movable section to suck and hold the workpiece, and has positioning pins stretched in vertically lower direction and, at loading time, the workpiece held by the movable section into the carrier holding hole, the positioning pins are appressed against tooth-bottoms of a gear on the carrier outer periphery and movable section moving within the parallel plane. The carrier is pushed against the sun gear side to fix the carrier position and direction, and the held workpiece is carried into the holding hole. Consequently, the automatic handling apparatus load the workpiece into the carrier holding hole.

Abstract: The present invention relates to a polishing method and a polishing apparatus for polishing a substrate such as a wafer while measuring a film thickness based on optical information included in reflected light from the substrate.

Abstract: An abrasive jet cutting system may include a differential pressure measurement apparatus configured to measure a differential pressure between points in an abrasive supply system. The differential pressure may be used to determine one or more conditions of the jet and the abrasive delivery. The measured differential pressure may be used in a feedback control system, feed forward control system, and/or an alarm or safety system.

Abstract: Provided is a shot-blasting apparatus which is capable of efficiently perform dust collection and ventilation of an inside of a projection chamber, even using a dust collector having a small-size and low-cost suction device.

Abstract: An abrasive tool can include a bonded abrasive including a body and a barrier layer bonded to a major surface of the body. The body can include abrasive particles contained within a bond material. The barrier material can include a polymer including a biaxially-oriented material. In an embodiment, the barrier layer may include a polymer-containing film as an exterior surface of the abrasive tool. The abrasive tool may be formed such that the barrier layer is formed in-situ with the formation of the bonded abrasive.

Abstract: Disclosed generally is a quick change face plate for a vise.

Abstract: The present invention discloses a force relieving mechanism and a ratchet clamp having a force relieving mechanism. The force relieving mechanism includes a first ratchet member, a second ratchet member, a locking member, an actuating member and a restoring member. A first clamp arm of the ratchet clamp is fixedly arranged with a first ratchet member having a first set of ratchets, and a second ratchet member having a second set of ratchets is coupled to the second clamp arm by a second shaft and is rotatable in relation to the second ratchet member. The second ratchet member is provided with a first hole, the locking member passing through the first hole and being rotatable and translationally movable in the first hole. The actuating member applied a first actuation and a second actuation in turn to the locking member so as to cause the second set of ratchets to be detached from the first set of ratchets.

Abstract: An electric screwdriver includes a motor having a motor shaft, a handle housing for accommodating the motor, an output shaft at least partly protruding from the handle housing, a transmission device for enabling the motor shaft to drive the output shaft to rotate around a first axis, an exploring antenna for detecting whether an object is charged, an operating switch coupled to the handle housing for controlling the motor, a first wire stripping member fixedly mounted to the handle housing; and a second wire stripping member rotatably connected to the handle housing.

Abstract: In order to provide an electric tool such that the capacitances of noise-suppressing film capacitors can be increased without increasing the diameter of a handle section, the housing of the electric tool comprises: a body section that stores a brushless motor, a striking mechanism part, and a portion of an output part; a handle section, whose one end is connected to the body section; and a storage section that is formed on the other end of the handle section. A pair of film capacitors for removing noise generated from an inverter circuit are mounted on a capacitor substrate and stored side by side inside the handle section. The film capacitors are connected in parallel with each other, thereby providing a capacitor having a larger total capacitance than before.

Abstract: An impact tool includes a housing, a motor supported in the housing, and a drive assembly for converting a continuous torque input from the motor to consecutive rotational impacts upon a workpiece. The drive assembly includes an anvil, a hammer that is both rotationally and axially movable relative to the anvil, and a spring for biasing the hammer in an axial direction toward the anvil. The spring is rotationally unitized to the hammer for co-rotation therewith at all times during operation of the impact tool.

Abstract: A ratcheting flex-wrench device. The device includes an elongated handle having opposing ends, each opposing end having an integral yoke and a tool head pivotally coupled to the yoke. Each tool head includes an annular socket member rotationally disposed within the tool head. The annular socket member is configured to engage a Torx external hexalobular fitting of a workpiece. The annular socket member includes internal contours matching the outer lobe contours of the Torx external hexalobular fitting. Each tool head includes a ratchet mechanism configured to provide one-way directional rotation of the annular socket member.

Abstract: A magazine strip that is fed to a drive-in device via a chute extending at an angle to the drive-in direction is disclosed. A deflector consisting of tongues is provided at the outlet end of the magazine guide, which deflector deflects the magazine strip away from the straight-ahead direction and directs the magazine strip quasi upward such that the magazine strip either extends perpendicularly to the drive-in direction or even back in parallel with the insertion chute, depending on the extent of the deflection. In order that the magazine strip follows this motion, the magazine strip has hinges, the axes of which extend transversely to the longitudinal direction of the magazine strip, and thus, at an angle to the screws located in the retainers of the magazine strip.

Abstract: A magnetic socket contains: a body and at least one magnetic attraction element. The body includes a connection segment and a fitting section, the connection segment has a polygonal coupling orifice defined therein and configured to accommodate a socket wrench, and the fitting section has a locking orifice formed therein and configured to lock a screw or a nut made of metal, wherein the locking orifice is polygonal. The body further includes at least one through orifice arranged on the fitting section and communicating with the locking orifice, and each of the at least one magnetic attraction element is housed in each of the at least one through orifice. Thereby, the magnetic socket is driven by the socket wrench so as to rotatably lock or remove a screw or a nut, and the magnetic socket magnetically attracts the screw or the nut, after removing the screw or the nut.

Abstract: A method for controlling an electric motor of a power tool having a receptacle for a tool, at least a current of the electric motor and/or a rotation speed of the electric motor during an impact operating mode of the electric motor being detected as a parameter, a driving time of the electric motor for the impact operating mode being specified as a function of the detected parameter. A method is also described for controlling an electric motor of a power tool having a receptacle for a tool for unscrewing a screw from a mating part.

Abstract: A long holding strap, which depending on the counter-clockwise or clockwise lacing of the strap, can assist the user in holding an engine pulley from turning in order to tighten or loosen the hold down nut or bolt, due to the friction exerted on the strap itself. The strap differs from other similar type products on the market today in that there are no other needed attachments that may interfere with the other engine components, while the engine is still installed in the vehicle where there is limited space and access.

Abstract: An ergonomic front fork service tool for servicing front fork tubes of a motorcycle includes a long threaded screw engaged in a threaded housing with a swivel foot at the bottom end and a large hand knob at the top end. The threaded housing is attached to a swinging arm attached to a vertical rod support. A base bar has a hollow tube attached at a right angle a distance away from its distal end, which receives and supports the vertical rod while permitting both swinging of the arm and vertical adjustment. The position between the rod and tube is locked by fasteners threaded transversally in the top wall of the tube. A portion of the base bar is used to support the service tool in a bench vise, or to fasten to a work bench, and two swinging gate clamps engage two front fork tubes and rigidly attach them during service to the bench top vertically.

Abstract: The invention relates to a tool device (1) for connecting a plastic tube or a metal/plastic composite tube to a fitting with a sliding or pressing sleeve, comprising a housing (2); an expansion device (3) for expanding the ends of the plastic tube or the metal/plastic composite tube; a sliding device (4) for sliding on the sliding sleeve or a pressing device for pressing on the pressing sleeve; and a drive element (5) which can be operated mechanically and which can be actuated in a switchable manner in order to drive the expansion device (3) or in order to drive the sliding or pressing device (4). The expansion device (3) and the sliding or pressing device (4) are connected to the housing (2), and the drive element (5) can be switched between driving the expansion device (3) and driving the sliding or pressing device (4) by rotating the housing (2) relative to the drive element (5).

Abstract: Gland puller for use in rebuilding hydraulic cylinders. Upon insertion of the first end of the elongated rod into a shaft hole of the hydraulic cylinder gland assembly beyond a first point, the rotating protrusion member is configured to rotate from the first position to the second position, and upon rotating the threaded collar along the threaded portion towards the first end, the elongated rod is configured to be pulled back from the first point to a second point where a surface of the at least one end of the rotating protrusion member is configured to abut an inner surface of the hydraulic cylinder gland assembly while a surface of the threaded collar is configured to abut an outer surface of the hydraulic cylinder gland.

Abstract: In order to provide a driving machine which achieves reciprocating movements of a rack using a simple mechanism and is able to smoothly engage and disengage the rack by reducing the friction during engagement and disengagement of the rack, the driving machine is equipped with: a nose that extends in a prescribed direction; a housing that has the nose; a blade that has an engaging section, is movably guided in the housing in the prescribed direction, and is capable of driving a fastener via the nose; and a transmission mechanism that has an engaged section for engaging with the engaging section in order to transmit a driving force, wherein the transmission mechanism has a roller mechanism for guiding the engaging section and engaged section to disengage from each other.

Abstract: A stapler includes a penetrating part including a pair of cutting blades to form holes in a workpiece and to cause leg portions of a staple to penetrate the workpiece, an operating member, and a bending part configured to bend the leg portions. The bending part includes a bending member configured to bend the leg portions of the staple, and a driving force transmitting section configured to transmit an operation of the operating member to the bending member.

Abstract: A stapler includes a main body having a front side and a bottom side extending from the front side. A staple discharge opening is defined on the bottom side proximate the front side. The stapler further includes a magazine movable between a received position within the main body and a withdrawn position, and a latch mechanism including an actuator movable between a latched position and an unlatched position. When the magazine is in the received position and the actuator is in the latched position the magazine is retained from movement toward the withdrawn position, and when the actuator is in the unlatched position the magazine is movable relative to the main body from the received position to the withdrawn position. The actuator is positioned within a recess defined by the main body when the magazine is in the received position.

Abstract: A tool assembly includes a first part, a second part, an operation member, two second tool units, and two first connection members. The first part has a first space, two first rails, two first engaging portions, two second spaces and two first connection portions. The second part has a head and a receiving portion which is insertion in the first space and includes receiving units for receiving first tools therein. Two second rails are formed on the second part and slidably engaged with the first rails. The operation member is connected to the second part. The two second tool units are pivotably connected to the two first connection portions and located in the two second spaces. The second tool units each have second tools which are pivotable about the first connection portion corresponding thereto. The first tools can be removed from the receiving units and connected to the operation member.

Abstract: Systems and methods for reducing vibration in power tool. One system includes a power tool that includes a housing and a motor. The power tool further includes a magnetically susceptible fluid located within the housing. The power tool further includes an inductor configured to introduce a magnetic field to the magnetically susceptible fluid. The power tool further includes a sensor configured to indicate an amount of vibration experienced by the power tool. The power tool further includes an electronic processor coupled to the sensor and to the inductor. The electronic processor is configured to receive an input signal from the sensor indicating the amount of vibration, to generate a control signal based on the input signal, and to provide the control signal to the inductor to control the magnetic field.

Abstract: A disassembly tool kit for replacing vehicular decorative plates comprises a handle including a handheld end and a handle-side engagement end far away from the handheld end,; and at least one replaceable tool each including a tool-side engagement end corresponding to the handle-side engagement end and a working end far away from the tool-side engagement end. The handle-side engagement end includes a first fixing element and a first locking element. The working end includes a decorative-plate disassembly element. The tool-side engagement end includes a second fixing element corresponding to the first fixing element for a press-fit engagement and a second locking element corresponding to the first locking element for a locking effect. The user may select an appropriate replaceable tool according to the decorative plate or strip, which is to be disassembled, and install the replaceable tool in the handle.

Abstract: A tool retaining apparatus including a base and a tool support secured to the base. The tool support has a pair of spaced arms for supporting a tool there between. A securement member is disposed on the base between the two arms. The support member has a distal end. The distal end and the pair of spaced arms forming a tool holding space there between adapted to receive at least a portion of a tool. The distal end is movable between a first position wherein a path to the tool holding space is closed to prevent removal of the tool therefrom and a second position wherein the path is open to permit removal of the tool from the tool holding space.

Abstract: A tool box includes two first bodies and each first body has two first connection portions on the first end thereof. Two connectors are respectively connected to the first connection portions and each connectors has a second pivotal portion and a third pivotal portion. The second pivotal portion is a tubular portion with a C-shaped cross section which includes an elongate opening defined axially therethrough. The width of the elongate opening is smaller than the inner diameter of the second pivotal portion. The third pivotal portion is a rod which shares a common axis with the second pivotal portion. The diameter of the third pivotal portion is equal to or smaller than the inner diameter of the second pivotal portion. The third pivotal portions on one of the two first bodies are pivotably connected to the second pivotal portions on the other one of the two first bodies to pivotably connect the two first bodies.

Abstract: Disclosed is a tool holder for releasingly holding an air tool. The holder comprises a housing comprising at least one horizontal tool track, each of which for slidably receiving the stepped annular spout of the tool therewithin through a track point, the housing adapted to be secured to a vertical surface about the rear thereof, which is perpendicular to the track, and at least one hinge member hingedly secured within the housing such that, the at least one hinge member is angularly movable between an open and a closed position, the at least one hinged member biased towards the closed position. Each of the at least one hinge member comprises at least one blocker, each of which for blocking and unblocking the track point in the closed and open positions respectively.

Abstract: Disclosed is an adjustable tool holder for holding elongate handheld tools. The tool holder comprises a telescopically adjustable base member comprising an elongate, rectangular, hollow outer member and an elongate rectangular inner member configured to be snugly and slidably received within the outer member, the inner member adapted to be secured to the outer member at a plurality of lock positions thereby rendering the length of the base member adjustable. The tool holder further comprises a compression spring, one end of which is secured at the free end of the outer member and the other end of which is secured at the free end of the inner member. The length of the spring is subject to change in accordance with the change in the length of the base member. A tool is adapted to be held between two consecutive loops of the spring.

Abstract: A magnetic hand tool frame includes a baseboard, at least one clamping element, and two attraction modules. The baseboard has a body and at least one clamping rack formed on the body. The at least one clamping element is connected to the at least one clamping rack. The attraction modules are connected to the baseboard respectively at two opposite sides of the body, and each has a holding mount and a magnetic base. The holding mount is connected to the body at one of the opposite sides of the body, is opposite to the at least one clamping element and has a connecting rack formed on the holding mount. The magnetic base is connected to the holding mount in the connecting rack and has a mounting frame and at least one magnetic block securely mounted in the mounting frame to provide a magnetic attraction effect to the magnetic base.

Abstract: The embodiments relate to a distributed marsupial robotic system. The system includes a parent component having a sensor suite to obtain and process environment data via a parent pattern classification algorithm, and one or more child components each having a sensor suite to obtain and process environment data via a child pattern classification algorithm. Each sensor suite includes one or more sensor devices in communication with a processing unit and memory. Each child component is configured to dock to the parent component, and to separate from the parent component in response to a deployment signal. Each child component obtains environment data during separation. The parent component is configured to construct a map of the environment by receiving and integrating the data obtained by each child component.

Abstract: A control device of a robot for controlling the angle of a joint of the robot that is driven by a motor. The control device is equipped with: a joint angle command-calculating unit for calculating a joint angle command value; an axial force torque-calculating unit for calculating the axial force torque generated in the joint axis; an elastic deformation-compensating unit for calculating a motor command angle by adding a joint deflection, which is calculated from the axial force torque and a joint spring constant, to the joint angle command value; a stopping position-detecting unit for detecting the angle of the motor when the robot contacts an external structure; and a command angle-switching unit for outputting the motor angle detected by the stopping position-detecting unit instead of the joint angle command value when the stopping position-detecting unit outputs the angle of the motor.

Abstract: Robots capable of accommodating dynamic replacement of end effectors load and run software that allows the end effector to be operated without change to the main control program. The driver may be dynamically linked and run during program execution when the corresponding end effector is detected. Typically, the robot controller will store a library of drivers, and load the appropriate driver when a new end effector is detected.

Abstract: A trained classifier to be used with a navigation algorithm for use with mobile robots to compute safe and efficient trajectories. An offline learning process is used to train a classifier for the navigation algorithm (or motion planner), and the classifier functions, after training is complete, to accurately detect intentions of humans within a space shared with the robot to block the robot from traveling along its current trajectory. At runtime, the trained classifier can be used with regression based on past trajectories of humans (or other tracked, mobile entities) to predict where the humans will move in the future and whether the humans are likely to be blockers. The planning algorithm or motion planner generates trajectories based on predictions of human behavior that allow the robot to navigate amongst crowds of people more safely and efficiently.

Abstract: The invention relates to a method for programming a robot, in particular a robot comprising a robotic arm, in which method a movement to be performed by the robot is set up preferably in a robot programme by means of a predefined motion template, the motion template is selected from a database comprising a plurality of motion templates, the motion template comprises one or more execution modules that can be parameterized and at least one learning module, the one or more execution modules are used for planning and/or performing the robot movement or part of the robot movement, the leaning module records one or more configurations of the robot during an initialization process, in particular in the form of a teaching process, and the learning module calculates parameters for the one or more execution modules on the basis of the recorded configurations, preferably using an automatic learning process. Also disclosed is a corresponding system for programming a robot.

Abstract: A robot teaching position correcting method and system is provided. The robot is driven to move along wafer pick-and-place operation paths defined by a sequence of waypoints. Distances between the waypoint and a wafer supporter of the wafer carrier above the waypoint are detected by upper sensors provided on a top surface of the robot when the robot is positioned at the waypoint. Then, the position parameter of the waypoint is corrected accordingly, so as to ensure safe wafer handling.