Abstract: A redundant robot control scheme is provided for avoiding obstacles in a workspace during motion of an end effector along a preselected trajectory by stopping motion of the critical point on the robot closest to the obstacle when the distance therebetween is reduced to a predetermined sphere of influence surrounding the obstacle. Algorithms are provided for conveniently determining the critical point and critical distance.

Abstract: A five-axis robot mechanism for moving an operative device along three rectilinear axes and two rotational axis including a carriage movable along one rectilinear axis, a cart movable on the carraige and a mast assembly having two elongated members movable along a third rectilinear axis. The two elongated members are rotatable together one rotatable with respect to the other to produce movement of the operative device on two rotatable axes. The carriage, cart and mast assemblies are uniquely arranged with respect to each other produce the five-axis desired movement of the operative device.

Abstract: An improved break-away, end-of-arm robotic tooling assembly that has been designed to prevent damage to the robot arm in the event it would come in contact with something it should not. The robotic tooling assembly has a two inch inside diameter bore for air and paint lines. The robotic tooling assembly is compliant in all directions with the exception of a pulling force and it can be reset on repeating registration structure within the robotic tooling assemble. An air switch is incorporated which instantly signals the robot controller to perform an emergency stop.

Abstract: A robot operating method capable of easily performing manual correction of a previously taught teaching point during an automatic robot operation, and of accurately and effectively performing a desired robot operation without the need of employing a visual sensor. After switching is made from an automatic operation mode to a manual operation mode in response to reading of a predetermined command code from a program (S1, S2), a robot tool positioned at a first teaching position is moved to a first working position on a workpiece by a control apparatus which responds to an operation of a remote operation board by an operator, so as to compensate for a dislocation of the teaching point attributable to a positional dislocation of the workpiece (S3), and then a correction data indicative of the results of a manual adjustment is calculated in response to supply of an external signal generated by an operator's operation and is stored in a memory (S4, S5).

Abstract: Method and device for controlling a powered automotive seat of a rotatable type, wherein said seat is caused to move to a neutral position where said seat is free from contact with other adjacent fittings or other occupant, before being subjected to automatic rotation between drive position and climbing/descending position. Further, such automatic rotation of seat is permitted only when a door detector detects the door to be opened at an opening angle larger than a predetermined angle.

Abstract: Important performances of a robot of articulated type include a wide range of operation and an easy maintenance. In order to improve the performances, it is extremely advantageous to arrange an arm in a cantilever manner, in a point where components are difficult to interfere with each other, a point where confined portions of joints are brought to a single location, and so on. Conventionally, however, the following various drawbacks occur. That is, if the arm is arranged in a cantilever manner, moment loads applied to a plurality of bearings forming respectively the rotational joints increase, and an offset occurs between axes of the respective rotational joints so that computation for control becomes complicated. For this reason, the conventional robot, in which the arm is arranged in a cantilever manner, deteriorates in performance as compared with a robot in which an arm is arranged in a straddle manner, in a service life of the robot, easiness in computation of a control device, and so on.

Abstract: In a multi-jointed robot, position controllers are located at each of the joints of the robot and are interconnected by a unitary bus. The bus carries a loosely-regulated voltage to all of the controllers and also includes data conductors connected to the controllers for disseminating position commands which are time-division multiplexed.

Abstract: A control circuit (10) for an extrusion die (13) is operatively arranged to supply a command signal (e.sub.c) to an actuator (24,25) for controlling the movement of a mandrel (11) relative to a die head (12) as plasticized material is extruded through an orifice (14) to form a parison (15). The controller includes a memory (28) for receiving and storing a plurality of initial set points supplied from a keypad (29). A recalculation circuit (42) is operatively arranged to recalculate the magnitude of each set point according to the equation S.sub.n(r) =(S.sub.n(i) -G.sub.1)B+G.sub.2, where S.sub.n(r) is the recalculated value a particular set point, G.sub.1 is a first reference die gap, G.sub.2 is a second reference die gap, B is a scaling factor, and S.sub.n(i) is the corresponding initial set point stored in memory. The recalculation circuit is operatively arranged to supply each recalculated set point to the memory to replace the initial set point stored therein.

Abstract: When a welding teaching program employing a plurality of robots is completed, if a robot does not operate properly it may be preferably to make the robot retreat and operate in accordance with a different teaching program, urgently and at an optional timing. In the invention, when the operation of a program being executed is suspended, the program addresses are memorized and a different prestored teaching program is executed. Upon the termination of the different teaching program, the execution of the suspended program is resumed, referring to the memorized addresses.

Abstract: A stepping motor having independently energizable windings for respectively producing magnetic fields at right angles to each other and directed at the axis of a rotor having a fixed polarity perpendicular to its axis, is operated so that the advance from one step to the next is produced by energizing one winding with a voltage producing a current continuously in one direction, while the voltage applied to the other winding is a rectangularly alternating voltage of a constant period and a gradually changing keying ratio. The roles of the two windings are interchanged between successive steps. A microcomputer for control of the motor has a pulse timing table and a program memory. Two control code memories are provided, one for specifying the direction of current in each of the windings during pulses of a sequence and one for specifying the direction of current in each of the windings during pauses between pulses of a sequence, as well as during an energized interval preceding the beginning of a pulsed step.

Abstract: In a feedback controller for NC controlled machine tools, the position and the velocity of a work is detected and compared with the desired position. By this comparison, the work velocity is calculated and compared with the current velocity, which determines torque of a driving motor. A torque compensation signal generator, receiving the current velocity, generates a compensation signal according to a predetermined velocity/torque function. The signal is composed with a torque signal passed to a driving motor, and torque compensation is performed. A periodic reaction detector detects periodic fluctuation of the work caused by periodic load fluctuation, and a torque compensation direction causes a signal generator to suppress the fluctuation at desired occasions.

Abstract: An industrial robot system comprises a control unit including programs for operating an industrial robot and a peripheral device of the industrial robot according to the programs; a memory for storing the steps of the programs which are effected when the industrial robot and peripheral device are stopped unintentionally; a detector for detecting the conditions of the industrial robot and peripheral device when the industrial robot and peripheral device are stopped unintentionally; and a restarter for starting the industrial robot and peripheral device again when the contents of the memory coincide with the conditions detected by the detectors.

Abstract: A robot control system including a robot, a robot controller for controlling operation of the robot, and a teaching box for teaching the robot through the robot controller. The teaching box includes an input unit separate from the robot controller for entering a command signal to teach the robot its operation to be effected and a control unit for controlling the input unit and processing and for applying the command signal to the robot controller.

Abstract: In a method of operating a press machine having a servomotor (20) and a servo controller therefor, the tool stays substantially still immediately after the completion of working a workpiece for a period of from 0.05 to 2 seconds and also the speed of the tool applying an impact to the workpiece for working is decelerated immediately before the tool strikes against the workpiece in order to reduce the noise generated when the impact is applied. The speed and positional locus of the ram (36) are set for each step using respective setting switches provided on a panel. The servomotor (20) is program-controlled according to the data input through the respective setting switches.

Abstract: A numerical control device capable of controlling the drive of a plurality of objects to be controlled in a parallel mode. With a numerical control device, machining programs for the objects which should be executed in parallel, are able to being displayed or printed in a parallel mode so that the parallel driving condition can be detected visually. Further, the machining program is suspended to be listed in response to a queuing instruction as an empty block, so that the queuing instructions for the plural objects are arranged in the same line thus printed or displayed.

Abstract: A method for control of servomotors includes limiting velocity feedforward as a second input to a velocity control loop in response to a velocity command, which is a first input, reaching a predetermined limit. Gain parameters for proportional and integral portions of a velocity-torque control loop and for the proportional and integral portions of the velocity feedforward loop may be adjusted independently to obtain varying control responses from the control system. The method is carried out in a microcomputer-based control module for an industrial controller.

Abstract: An orthogonal two-axis moving apparatus includes a first guide member which extends along one direction and is attached to a stationary position, a slide block which is slidably supported on the first guide member and is movable in the one direction, and a second guide member which extends along the other direction perpendicular to the one direction and is supported by the slide block to be movable in the other direction. First and second rollers are pivotally supported on two ends of the first guide member, a third roller is pivotally supported on one end of the second guide member, and intermediate rollers are pivotally supported on four corner portions of the slide block. A coupling belt is provided and has two ends of which are fixed to the other end of the second guide member and which is looped in a cross shape on the first to third rollers and the four intermediate rollers.

Abstract: Disclosed is a machining data display system for displaying data at a display of a numerical control apparatus (CNC) while a machining operation is being carried out, wherein machining data (11) to (14) specified by a machining program are selected from machining data registered in advance and displayed at the display (10). With this arrangement, machining data actually required is displayed and machining conditions are correctly monitored.

Abstract: A detection apparatus is provided which is capable of detecting an excessive position error in a servo system in an appropriate manner over a wide servomotor rotational rate region, so as to accurately and immediately determine an overload state of a servomotor and the like. A permissible maximum value of the position error is obtained by first obtaining a product of a proportional coefficient set beforehand and a maximum value of pulse distribution amounts--a number of movement command pulses distributed from a central processing unit of a numerical control unit. The pulse distribution amounts are respectively stored in a table provided in a memory. The product is then, second, divided by a position loop gain. The central processing unit then determine that an excessive position error has occurred when an actual position error read from an axis controller is greater than or equal to the permissible maximum value.

Abstract: In a control (100) for a variable displacement hydraulic motor (12) having an electrically controlled hydraulic servo valve (14) for controlling the displacement of a hydraulic motor by varying position of a wobbler (28) in response to a servo valve control signal, a velocity transducer (72), coupled to a shaft (30) driven by the motor, for providing a velocity signal representative of the velocity of the shaft, and a wobbler position sensor (84), coupled to the wobbler, for producing a wobbler position signal indicative of the position of the wobbler, an improvement in accordance with the invention includes a controller (100) for producing the servo valve control signal as a function of a wobbler position command specifying a position of the wobbler wherein the wobbler position command is a function of at least one of the velocity signal representative of the velocity of the shaft and the wobbler position signal.

Abstract: A high-precision pulse interpolation method for interpolating the amount of movement of individual axes of a numerical control apparatus (1) with high precision. An interpolation pulse is output twice or more in one task and is written into a shared RAM (2). A servo control circuit (3) outputs the interpolation pulses in the shared RAM at regular intervals, to control a servometer (5) with a high-precision pulse interpolation.

Abstract: Stable compliance control at a high speed is achieved by cooperation between a manipulator and a wrist body which is located at the end of the manipulator arm.

Abstract: The Seat Base Motion Controller provides automated control of seat motion for seat systems employed in providing combined visual and motion experience for patrons in amusement rides and the like. Occupant safety features are integrated within the seat motion control system and centralized control of multiple motion bases is accomplished. Motion control of the seat bases is responsive to a position signal input coordinated with a visual presentation viewed by the patrons. Self contained power systems for the actuation means of the seat base allows sizing of an entertainment threater to accommodate anticipated audiences. Independent control and operation of each motion base precludes the need for shutting down the entire theater if a fault exists in one motion base or the safety systems on that motion base are activated.

Abstract: A numerical control system controls a plurality of axes with a plurality of channels (10, 20, 30). When a machining program for a first channel (10) is interrupted after a single block in response to a single block signal (6), the feeding of commands of a machining program for other channels (20, 30) is held. The machining programs are thereby executed in synchronism with each other. The machining processes are prevented from being unbalanced, and machining interference is avoided.

Abstract: A system for teaching, controlling and monitoring industrial robots includes a storage section storing data describing working positions and motion patterns of the robots, and a teaching section for automatically preparing a teach data of each robot by selecting one of the different working positions and one of the motions patterns for the robot in accordance with the kind of work. The system may further includes a graphic processor for displaying picture images of the robots, their tools and workpieces, and a checking section for searching for robot-robot interference by checking a collection of data describing spaces occupied by the robots, and modifying the teach data to avoid such an interference.

Abstract: A numerical control device for a multi-axis lathe which is capable of controlling movements of a plurality of tools simultaneously. With the numerical control device, the movement of a first tool in a Z-axis direction is controlled according to the movement of a workpiece to be machined and the other movement of remaining tools in the Z-axis direction are controlled taking the Z-axis movement of the first tool into consideration, so that the different machining operations using different tools can be attained simultaneously or successively.

Abstract: A robot controller for an articulated robot, capable of controlling the articulated robot for the highly accurate high-speed movement of the work along a predetermined route. The robot controller a memory for previously storing functions for calculating position gains and speed gains for the joints of the articulated robot. A detecting operates to detect the present position and present speed of each of the joints during the operation of the articulated robot. A first calculating operation calculates a position gain and a speed gain for each joint on the basis of the present position and present speed of the joint detected by the detecting feature by using the functions stored in the memory. A second calculating operation the calculates instructions to be give to the actuators on the basis of position instructions, the present position and the present speed of the joints detected by the detecting feature, and the position gains and the speed gains calculated by the first calculating operation.

Abstract: Device for pivoting a motor-vehicle mirror in or at a car from the normal position (fully-reflecting condition V) to a non-dazzle position (partly-reflecting condition T) in the event of excessive glare (B) from the headlight of a following vehicle and taking into account any interference from ambient light (U), said device comprising a voltage-source, a motor (M), the shaft (10) of which acts upon the mirror through a tilting mechanism and which is fed from thyristors (T1 and T2) which are, in turn, controlled by transistors (TR1, TR2 and TR3) with the aid of photodiodes or photoresistors (B, U) for glare and interference from ambient light. A bipolar rotary switch (DS) is connected in series with the motor (M), said switch interrupting the flow of current through the motor in accordance with a specific angle of rotation of the shaft thereof, disconnecting the previously conducting thyristor (T1 or T2) from the voltage-source and switching it off.

Abstract: A scanner motor controller for a laser printer or the like having a polygonal rotating mirror rotated by a scanner motor to reflect a laser beam for scanning operation. The scanner motor controller comprises a rotating speed control circuit for controlling the scanner motor for operation at a constant rotating speed on the basis of phase deviation and frequency deviation of a FG pulse signal generated by the scanner motor from a reference clock, and a rotating speed varying circuit for varying the rotating speed of the scanner motor within one turn of the polygonal rotating mirror.

Abstract: A motor drive method is provided which is capable of preventing suspension of operation of an industrial robot, and preventing deviation of the track of movement from a command track, attributable to an overload state of a motor. Output torque command values for motors for various axes of the robot are detected (S1). When any one of the detected values exceeds a predetermined value, which is determined in accordance with the maximum output torque of each corresponding one of the motors for the various axes, an amount of move command per unit time, for every one of the axes, is reduced. The amount of move command per unit time is reduced by using the torque command values thus increased, the product of an override value and a coefficient obtained in accordance with the differential of the torque command values (S3, S6 and S14), whereby the overload state of the motor is prevented.

Abstract: In an industrial robot employing electric motors (Mz, M.theta., Mu, Mw) as drive sources for driving functional robot units for movement respectively about articulatory axes (Z, .theta., U, W), electric drive currents supplied to the electric motors (Mz, M.theta., Mu, Mw) associated with the articulatory axes (Z, .theta., U, W) are detected by a current detecting unit (30), the detected electric drive current supplied to the electric motor (Mz, M.theta., Mu, Mw) associated with one selected articulatory axis among the articulatory axes (Z, .theta., U, W) is sampled every predetermined minute sampling time in a period between a first time and a second time in a robot control program for controlling the motions of the functional robot units respectively about the articulatory axes (Z, .theta., W), computing means (CPU) calculates the ratio of the root-mean-square value of the electric current supplied to the electric motor (Mz, M.theta.

Abstract: A software servo control apparatus for use in an electrically-operated injection molding machine, which is capable of changing servo control variable constants, without the need of changing hardware arrangement, for greatly enhancing versatility for the machine, and of effecting appropriate pressure control. A servo control microprocessor (13) operates, in accordance with a servo control program, to determine a commanded current on the basis of a positional deviation amount, obtained from an output of a pulse encoder (5), and a moving command. The servo control microprocessor also determines an amount of a change in the output of the pulse encoder, and supplies a power amplifier (6) with the difference between the commanded current and an output of the same amplifier, for control of the drive of a servomotor (2). Further, the output of the amplifier is restricted to a value less than a commanded torque on the basis of an output of a pressure sensor (4) and the commanded torque.

Abstract: A driving apparatus for smoothly driving a running unit of a robot, including a movable table movably supported by first and second gear mechanisms driven by independent first and second motors engaging with respective two parallel racks to carry a robot body.

Abstract: The present invention is a control system for a seven-degree-of-freedom robotic arm. The robotic arm (10) includes two links (12 and 14), each having two degrees of freedom, and a spherical wrist (26) having three degrees of freedom. The kinematics of the spherical wrist are decoupled from the kinematics of the arm. The four degrees of freedom of the arm create a redundancy which provides versatility in the positioning of the arm. Fixing the redundant arm parameter and locating the end point (24) of the end effectuator path away from areas of limited mobility results in a marked simplification of the algorithms which describe the equations of motion of the arm. Additionally, further computation reduction can be achieved by updating the control gains less frequently than every microprocessor cycle, such as updating once for every five degrees of pitch angle rotation of either joint.

Abstract: An apparatus for controlling an industrial robot in a shared manner using a plurality of operation controllers so that the robot automatically works under the optimum load condition. When power is turned on, the operation controllers (5) to (7) connected via a common bus (1) operate their own respective initial loaders to read control data (TCB) from an external memory (3) into their own respective memories (RAM) and any one of the operation controllers (5) to (7) loads the control data (TCB) and synchronization control data in a shared memory (4). When synchronized with each other, the operation controllers (5) to (7) load the tasks from the external memory (3) in their own memories (RAM), depending upon their capabilities determined by the control data (TCB) and upon their shares of the task. Therefore, the industrial robot is controlled in a shared manner depending upon the task that is loaded.

Abstract: This invention is directed to electro-magnetic alignment apparatus which includes a monolithic stage, a sub-stage, an isolated reference structure, force actuators interposed between the monolithic stage and the sub-stage for suspending and positioning the monolithic stage in space, sensors for sensing the position of the monolithic stage and outputting a signal to control circuitry, which compares the sensed position with a commanded stage position and outputs an error signal to the force actuator, and actuators for controlling the position of the sub-stage to follow the approximate position of the monolithic stage.

Abstract: The invention provides a servomotor control apparatus which performs standard mode-type velocity control. An acceleration signal is formed by a differential computation or difference computation, from a velocity signal fed back from a servomotor. An acceleration value of the servomotor (d) is estimated by a criterion model (2) of a velocity control system utilizing a current command T(S) formed in a velocity control loop. The computed acceleration and the estimated acceleration are compared and the current command T(S) is corrected in conformity with the results of the comparison.

Abstract: A numerical control method makes it possible to perform machining of a workpiece at a high speed with a desired accuracy. After start of pulse distribution, a determination is made as to whether or not both a block being executed and a next block of an NC program relate to a cutting command (steps S12 and S13). An in-position value (A, B), corresponding to the determination result, is then stored in a register (C). In the case of three control axes, when the deviations (.epsilon.x, .epsilon.y, .epsilon.z) between target moving amounts and actual moving amounts for the three control axes are less than the value stored in the register (C), positioning control for the present block is completed, and the execution for the next block is started (S10). This permits variable setting of the desired positioning accuracy to be carried out. The method is applicable for any number of control axes.

Abstract: A method for contactless profiling is performed while tilting an optic axis of a distance measuring probe (PB), which is capable of measuring a distance optically, by an angle .theta. from the vertical axis. When a point (P.sub.1) at which distance measurement is impossible is reached and measurement of distance the thus becomes impossible, the movement of the distance measuring probe (PB) is halted and the distance measuring probe is rotated to tilt the optical axis thereof from the vertical axis by the angle .theta. in the opposite direction, after which contactless profiling is resumed. Thereafter, when the points (P.sub.2, P.sub.3) at which distance measurement is impossible are reached, the distance measuring probe (PB) is made to perform the same operations so that contactless profiling may continue.

Abstract: An improvement in a numerical control apparatus for controlling a threading operation with a tap. A numerical control apparatus of the present invention which is simple in construction and needs no dummy mechanism such as a floating tapper; and which minimizes the drift of the tap in the bottom of a tapped hole by an instruction to a feed shaft which switches an acceleration or deceleration time constant, and a simultaneous instruction to a spindle device which controls the position of the spindle device. Thus, the machining precision of the bottom of the tapped hole is improved, and a high-speed tapping operation is possible. Furthermore, the numerical control device also is capable of preventing the tap and the threaded portion machined by the tap from being damaged upon an occurrence of an abnormal condition by an instruction from the removing control unit.

Abstract: Robot vision and optical location systems capable of recovery of "depth" information normally lost from the two-dimensional image collected by a conventional image system comprises a radiation source for projecting a beam of light or other suitable radiation from a known location onto a field of vision in a manner that provides information indicating the direction of projection of the beam, a detection device situated at a second known location for receiving light or other radiation of the projected beam, scattered or reflected by objects within the field of vision and providing information indicating the direction of the source of scattered or reflected radiation and an analyzer for comparing the projection location, direction of projection, detection location and direction of the source of detected, scattered or reflected radiation to determine the location of objects in the field of vision.

Abstract: A headrest control system for a motor vehicle equipped with a driver's seat and rear seats having adjustable headrests mounted thereon is disclosed which includes a driving motor for moving the headrest of the rear seat between an operative position for use and an inoperative retracted position, a first switch provided for actuating the driving motor, a second switch for actuating the driving motor, a memory for storing data of an optimum operative position of the headrest, and a sensor for detecting whether the rear seat is occupied by a passenger or not.

Abstract: The mailing machine includes a print drum and shutter bar assemblies and a transport system for receiving seriately and assuming displacement control over envelopes from a feed means. The mailing machine drive control system is a microcomputer in control of a first stepper motor which is a driving communication with the transport system, a second motor in driving communication with the print drum assembly and a third motor in driving communication with the shutter bar assembly. A speed sensing means inform the microcomputer of the incoming velocity of an envelope and a trigger sensing means informs the microcomputer of the relative position of the envelope with respect to the transport system and printing station. The microcomputer is programmed to determine the peak drum speed relative to the speed of an incoming envelope and a preselected pitch distance between successive envelopes.

Abstract: An NC unit processing method executes numerical control processing based on a numerical control program and sequence control processing based on a sequence program at predetermined times on a time-sharing basis. The processing method first stores a location of a sequence program to be executed next in a predetermined storage area in response to a first timer interrupt (IRQ.sub.n+1) generated during execution of the sequence program. Input/output processing based on an input/output program is then executed, followed by numerical control processing based on the numerical control program in response to a second timer interrupt (IRQ.sub.n) generated during execution of the input/output processing. When the numerical control program ends, the execution location of the sequence program is referred to, and sequence program processing is executed from this location until the first timer interrupt (IRQ.sub.n) is once again generated.

Abstract: A position and speed detecting device is provided. This device includes a detection-signal generator comprising a rotor magnet assembly having a plurality of magnetic poles and a coil pattern for signal detection which moves relatively facing magnetized bodies of the rotor magnet assembly, a speed-signal detector for taking out a signal for frequency detection from said coil pattern for frequency-signal detection to produce a signal for speed detection; and a position-signal detector for producing a signal for position detection from said coil pattern for position-signal detection.

Abstract: The invention is a servomotor control apparatus for controlling the positioning of a movable element of an industrial robot or NC machine tool. An NC unit or a robot controller detects displacement from a movable element that is to be positioned, such as a table, forms a position command regarding a servomechanism, and has a correction circuit (A) which receives quadrant data (BLF) regarding a backlash correction command. When there is a quadrant reversal for each axis of the movable element, frictional torque corresponding to the axis is stored and a torque correction command (FR) corresponding thereto is outputted. A torque command of a fully-closed loop servo system for performing control based on a fed back position detection signal is corrected by the torque correction command. The servomotor control apparatus can be applied to semi-closed loop servo system in which a backlash correction is possible, and not just to a fully-closed loop servo system.

Abstract: A moving component of a robot, such as a robot arm, is controlled to return from a given position to an original point after the moving component has traced paths established respectively by a group of successive motion data blocks including positional data representative of positions of the moving component. The moving component is moved on the basis of positional data in one of the motion data blocks which precedes a present position of the moving component, and then is moved on the basis of positional data in one of the motion data blocks which precedes said first-mentioned one of the motion data blocks. Therefore, the moving component is moved successively backwards along the paths based on the positional data in the motion data blocks.

Abstract: In a robot control apparatus, the results of processing regarding inertia terms of a motion equation are stored in accordance with the position of a robot arm. The computation period of the inertia terms can be set to be larger than a drive torque computation period. The robot is controlled with the same precision and, moreover, drive torque can be computed at a shorter computation time.

Abstract: An axis feedrate output system for CNC equipment which controls the position of a machining table in each axis by effecting feedrate control in accordance with a residual error between a position command and detected positional information in each axis. A current feedrate of the machining table in each axis is derived from the residual error, and a current actual feedrate of the machining table is synthesized using the current feedrate for the respective axes an output which represents the current actual feedrate of the machining table in the form of a ratio to a predetermined maximum feedrate is generated. An error register stores the residual error (servo error) between the position command for each axis from an MPU in the CNC equipment and the positional information detected by a position sensor and provides a feedrate command for effecting feedrate control.

Abstract: A system for controlling a robot includes a control portion (7) for supplying a control signal to and receiving a control signal from a servo unit (6) for carrying out a signal supply and a signal feedback to an electric motor (5) for driving a shaft executing a Z-axis linear motion, and threshold value supply portion (8) for supplying a threshold value to the control portion. Based on a comparison between a motor torque instruction value and a threshold value supplied from the threshold value supplying portion, an alarm is delivered and the process subsequently proceeds to a step of dealing with an abnormal condition when said motor torque instruction value becomes greater than a predetermined threshold value.