Abstract: A position controlling device including a shielding plate which can be moved by a motor, three pairs of light emitting elements and light receiving elements arranged on both sides of the shielding plate and a motor controlling circuit which can control the normal rotation, reverse rotation and stop of the motor with output signals from the light receiving elements and a foot switch or centering switch simple in the formation and making no misoperation with a noise.

Abstract: Automatic trim tab control system (10) for boats in which the controls are provided with an attitude sensing switch (14) which provides port/starboard, fore/aft correction signals to the system (10) for trim tab correction. A timing means (18) in the control system enables signals from the attitude sensing switch, if corrections are required, to be amplified (16) and then directed to the switching relays (20) for the trim tabs or other device requiring altitude correction. A digital embodiment (134) may also be used for applications other than boats.

Abstract: A control and monitoring provision for final control elements such as inking and dampening fountain keys or metering screws at printing machines. A displacement pickup disk is solidly connected to the movable part of the final control element together with sensing means having two sensing elements. The output of the sensing elements is fed to a circuit for recognizing the direction of rotation of the final control element and to an electronic counting device with optical display. In a following comparison circuit the preset set point values are compared with the actual values and the comparison circuit is followed by a circuit for reversing the direction of rotation of the motor and for opening of a gate having its inputs connected as desired with a preset set point device and a data carrier and the output of the gate is connected to a monitor provision and by way of a following amplifier to the final control element.

Abstract: The position adjusting drive unit for a sewing machine having its work shaft driven by an electromotor with an adjustable rotary speed, includes a supporting box connected to the electromotor and including a power supply transformer and an activation mechanism for a signal generator for desired and actual values of the rotary speed of the motor and of the angular position of the working shaft; an exchangeable printed circuit board supports all electrical and mechanical component parts of the speed regulating and angular position adjusting circuits including the signal generators and the coupling rod between the activation mechanism in the supporting box and the part of the activation mechanism on the circuit board is guided into the proper coupling position when the circuit board is electrically connected to the power supply transformer.

Abstract: There is a recording apparatus utilizing a linear motor in which a movable carriage is provided with a detector for detecting its speed and position while the apparatus itself is provided with a detector for detecting the initial position of the carriage.

Abstract: A stable positional reference system for use in improving the cutting tool-to-part contour position in numerical controlled-multiaxis metal turning machines is provided. The reference system employs a plurality of interferometers referenced to orthogonally disposed metering bars which are substantially isolated from machine strain induced position errors for monitoring the part and tool positions relative to the metering bars. A microprocessor-based control system is employed in conjunction with the plurality of position interferometers and part contour description data inputs to calculate error components for each axis of movement and output them to corresponding axis drives with appropriate scaling and error compensation.

Abstract: In a process and an arrangement for the copying of masks on a workpiece, especially for the projection copying on a semiconductor substrate for the production of integrated circuitries, a mask pattern is imaged on respective different, predetermined areas of the workpiece by a shifting of the workpiece in the image plane. In order to increase the accuracy of the individual imagings, the alignment error between the image of the mask pattern and the predetermined area of the workpiece is determined during the imagings of the mask pattern on the workpiece. The predetermined value of the displacement of the workpiece to the area for a subsequent imaging or the position of the mask is corrected to the extent of the alignment error.

Abstract: An electrical control system (31) for a tire building machine servicer (10) and method for controlling the position of a component material (13) emitted from the servicer (10) on a conveyor (12) includes an electrical guidance system (33) and an electrical drive tracking system (34). The electrical guidance system (33) includes two cameras (39, 40) providing pulse train output signals indicative of the position of the material edges relative to a fixed longitudinal axis (23), the number of pulses in which are counted in lateral position error counter (46) to provide an error correction signal to a conveyor position drive motor (30). The electrical drive tracking system (34) includes two encoders (81, 82) providing pulse train output signals indicative of the position of the component material (13) relative to the locus of points of an elastic material on a rotatable tire building drum (15).

Abstract: A driver for positioning the postage amount handles of a postage meter, the driver including motors which, in response to control signals from a postage computer, axially displace shafts along paths generally parallel to the paths of the postage meter handles. The shafts support actuator fingers which couple the shaft movement to the respective handles. An optical interruptor for each shaft senses various shaft positions and provides signals to the postage computer which are used in part to develop the control signals.

Abstract: A digital control circuit for use in automatic-focus cameras is disclosed, which is suitable for use in self-focusing systems which determine focus by means of triangulation. The system corrects for motor oscillation about a state of proper focus, defocusing caused by inertia, and for an inability to evaluate proper state of focus caused by large distances between the camera and a subject.

Abstract: A batch chip placement system for batch positioning semiconductor chips, or the like, upon a substrate containing an array of chip sites or footprints whose actual position on the substrate deviates from the theoretical or nominal position over successive substrates. The positioning is achieved by first sensing the X and Y offsets of a pair of alignment marks on the substrate from their theoretical or nominal position to determine the .DELTA.X and .DELTA.Y correction factors required to obtain the actual X,Y position of the alignment marks. The actual X,Y position of the alignment marks is used to determine actual X,Y chip position values, .theta. rotation and shrinkage factor corrections required to obtain proper orientation and positioning for batch chip placement.

Abstract: There is provided a motor control system adapted for use, for example, with a sample analyzer, having means for generating signals representative of motor movement, and a logic circuit for analyzing the motor movement signals to determine increments of movement and the direction of movement. Digital circuitry is also provided for tracking the actual motor position as it is moved in either a forward or reverse direction, and comparing the tracked position with a programmed destination position. When and only when the motor is within a predetermined range of the destination position is a variable control generated, causing braking of the motor so that it stops exactly at the programmed destination position.

Abstract: An electronically controlled thread-cutting machine comprising a pulse controlled stepping motor for driving the thread-cutting tool, sensor means for scanning an adjustable thread depth and the torque on the thread-cutting tool, said scanning means comprising a counter for determining the steps of the motor and the number of revolutions of the thread-cutting tool respectively therefrom for determining the depth of the thread, and the current consumption of the motor being used for determining the torque transmitted to the thread-cutting tool, the motor being controlled in accordance with the torque and depth of the thread by micro-processor means for reversing the motor when the torque exceeds an upper limit torque and when the desired and preselected thread depth has been attained.

Abstract: An apparatus is provided for determining the burning and/or glowing rate of a smokable article. The apparatus comprises a sensor for sensing the incandescent zone of the smokable article and a drive apparatus for moving the sensor along a path parallel to the direction of burning and glowing of the smokable article.

Abstract: In the process of aligning an image sensor (33) with a datum mark (23) on an artmaster (21), each of a plurality of elements of the sensor accumulate a charge based on the level of light sensed. The elements of the sensor (33) are repetitively scanned to obtain data pulses relating to the charges on the elements as an indication of the level of sensed light. Data pulses from selected elements of the sensor (33) are counted and compared to develop a signal representative of, and to facilitate visual indication of, the alignment or misalignment of the sensor (33) and the datum mark (23). If the sensor (33) and the datum mark (23) are misaligned, the developed signal facilitate control of servo motors (28 and 29) to move the sensor (33) into alignment with the datum mark (23). Data pulses derived from all elements of the sensor (33) are used to facilitate an electronic reproduction on a display board (40) of the position of the datum mark (23 ) relative to the sensor.

Abstract: A device for controlling movements of pickup arm in linear tracking pickup arm apparatus comprises an offset angle detecting mechanism of photo-electricity conversion type for detecting a horizontal offset of the arm and a servo mechanism for correcting the arm offset. The servo mechanism is disabled by turning-off a light-emitting element in the detecting mechanism when the pickup arm is at an uplifting position as well as at limiting end positions in a horizontal arm travel. The initiation of the servo action of the mechanism is effected gradually by gradual illumination of the light-emitting element.

Abstract: An arrangement for orienting an out-of-round workpiece into desired angular and lateral positions for a machining operation. The arrangement places the workpiece into a first location; determines the actual angular and lateral positions of the workpiece in the first location; determines the deviations between the respective desired and actual positions; moves the workpiece from the first location into a second location; and reorients the workpiece into the desired angular and lateral positions dependent upon correctional values derived from the above-noted deviations.

Abstract: An alignment apparatus for mask and wafer each having alignment marks provided in a narrow strip like area between circuit patterns is disclosed, which mask and wafer are used in manufacturing semiconductor circuit elements. In the apparatus, the mask and wafer are scanned to obtain scan signals by means of which the amount of relative deviation between the alignment marks on mask and wafer is detected. By means of the detected signal, an alignment is effected between the mask and wafer in the apparatus. For this type of alignment apparatus, there is a problem that since the alignment marks are provided in the narrow strip like area, no coincidence between the scanning position and the strip area is attainable with pre-alignment accuracy. Improvement in the alignment apparatus according to the invention lies in that a reading of alignment marks is initiated after the coincidence is photoelectrically detected.

Abstract: Disclosed is a control circuit of a positioning device for moving a member to be controlled to a predetermined position by using a d-c motor, in which there are used arithmetic circuit means for detecting a difference signal, to be converted to a driving signal of the motor, between the position detecting signal of the member and the reference signal of the predetermined position, and correcting circuit means coupled to the arithmetic circuit means for causing the difference signal to be small, whereby the motor is free from the hunting phenomenon.

Abstract: A digital control circuit for use in automatic-focus cameras is disclosed, which is suitable for use in self-focusing systems which determine focus by means of triangulation. The system corrects for motor oscillation about a state of proper focus, defocusing caused by inertia, and for an inability to evaluate proper state of focus caused by large distances between the camera and a subject.

Abstract: Disclosed is an interactive graphic apparatus for obtaining a desired formal drawing from a manuscript bearing rough drawings depicted thereon. In this apparatus, the operator can automatically draw onto a drawing paper put on a drawing table, on the basis of the positional information items of drawings on a manuscript disposed on a reading table and the functional information items inputted from a key board. The apparatus has particularly three component elements of digitizer, controlling device and plotter incorporated into an integral desk-like structure and various operational functions, whereby the interaction of the apparatus is improved.

Abstract: A detector for application to integrated circuits useful in determining the alignment of a trimming laser. A metallization pattern is employed along with electrical detection circuitry to determine when the trimming laser becomes misaligned by a predetermined amount. The laser is precision aimed when the integrated circuit wafer is located in a step and repeat machine. As stepping continues the detector provides an indication when the cumulative error exceeds the predetermined value.

Abstract: A robot assembly for acquiring unorientated workpieces from a bin. A sensing system views the bin and collects data. A computer analyzes the data to determine candidate holdsites on the workpiece. The hand of the robot assembly then engages a workpiece at a selected holdsite. The workpiece is moved to a pose where the position and orientation of the workpiece are determined. After this determination, the workpiece may be disengaged, or moved to an intermediate or final goal site.

Abstract: Apparatus is provided for sensing a location on a commutator and, in response thereto, actuating a tool for performing an operation on the commutator. The apparatus includes a device for mounting the commutator for rotation so that it may be indexed to successive commutator bars which are to be worked on. There is also a light source and a device for directing light from the source to the surface of the commutator, and a device for directing the reflection of light from the commutator surface to a sensing device. When the light beam impinges on a non-reflective area of the commutator so that the sensing device is not actuated, the sensing device signals a control circuit for stopping the rotation of said commutator and for actuating a tool for performing an operation on the commutator. In order to prevent the interference of ambient light with the operation of the sensing apparatus, a protective housing is provided for at least partially enclosing the light-directing devices.

Abstract: A method of aligning an x-ray mask to a pattern on a semiconductor slice utilizing an infrared light source and an alignment pattern pair on the mask and slice to automatically and precisely position the x-ray mask on the semiconductor slice.

Abstract: A system for precisely positioning a printed circuit board relative to a component insertion tool, the system including a circuit board-holding frame movable with two degrees of freedom in a plane by a servomechanism coupled to a photo detector assembly positioned on the opposite side of the printed circuit board from a light beam generator producing a single beam or a pair of parallel light beams spaced a distance equal to the distance between a pair of holes in the circuit board. Light pipes or a pair of orthogonally oriented wedge-shaped beam splitting members are positioned between the photo detector assembly and the circuit board for splitting each of the beams and thereby illuminating orthogonally oriented pairs of photo cells equally when the board is in a desired position relative to the light beams and providing to the servomechanism with an error signal to correct the position of the board when it is not in such alignment.

Abstract: In a positioning control system of the type which controls an object to be controlled to a target position by the use of a servo system, the present invention is characterized in that when a position deviation between the present position of the object to be controlled and the desired target position is smaller than a predetermined value, the servo system is actuated for a first period of time in accordance with the position deviation by means of a control signal which is greater than that normally warranted by the position feedback gain which is provided in the servo system, and is thereafter changed over to a servo system which is actuated by the position feedback gain either after a predetermined time or when a predetermined velocity has been achieved.

Abstract: A wrapping machine has a plurality of movable elements which move in predetermined ways to perform a wrapping operation. Control of the movements of at least some of the elements is performed using a pulse generator for synchronization and a control circuit which receives the pulses from the pulse generator. The control circuit comprises a computer having a suitable working program and peripherals connected to the computer and operating the associated element. Each peripheral comprises a processor controlled by the computer and a step-by-step motor which is controlled by the processor and which is operatively connected to the associated element to move the element.

Abstract: A method is provided for adjusting or setting a definite position of rest of a rotary tube, particularly of a tube mill, by switching off the drive of the tube and is particularly characterized in that, at a time T.sub.o, the angular position of the rotary tube, or of a drive part rotating with a tube, referred to a plane of comparison is established, that the idling movement of the tube is predetermined between disconnection and final standstill, and the angular position of the rotary tube and/or of the time T.sub.x at which the drive is disconnected is calculated and effected.

Abstract: A detector responsive to an angular offset between a gyrosphere of a gyrocompass and a tilt ring, forming part of a gimbal mounting therefor, controls a follower motor coupled through a reduction gearing with a suspension shaft for that mounting, the shaft being further coupled with a first synchro transmitter. A second synchro transmitter, electrically connected to several synchro receivers forming part of respective repeaters, is driven by a servomotor through a reduction gearing of step-down ratio 1:3 and is mechanically linked with a third synchro transmitter through a reduction gearing of step-down ratio 1:360, the third synchro transmitter being electrically connected to the first synchro transmitter for producing an error signal delivered through a feedback loop to the servomotor for keeping same slaved to the suspension shaft.

Abstract: A system is described for guiding a claw to the proper distance and into the proper orientation in yaw and pitch, to engage a grappling fixture. The system includes four proximity sensors on the claw, that are arranged at the corners of an imaginary square, which sense the distance to the top surface of the grappling fixture. If a pair of sensors at opposite corners of the square sense a different distance to the top surface of the grappling fixture, then it is known that the claw is rotated about a corresponding axis with respect to the plane of the grappling fixture.

Abstract: A control system is disclosed for acquiring and maintaining a register condition for successive repeat lengths of a moving web relative to a cut-off apparatus or the like in a web operating apparatus of the type which includes an adjustment means for advancing or retarding the web relative to the cut-off apparatus. The system operates in manual and automatic modes and while in the manual mode, an operator manipulates the adjustment means to obtain the register condition and then switches to the automatic mode which maintains the register condition.

Abstract: A digital servo system for maintaining a detection device, such as a light beam, centered as closely as possible over an information track, such as an optical track on a video recording disc. The servo system includes circuitry for detecting when the light beam traverses a switching line, which, in the illustrative embodiment, is the track centerline, for applying a constant-magnitude acceleration force to deflect the beam to a corrected position, and for reversing the polarity of the acceleration force when the beam traverses the switching line.

Abstract: A digital servo system for maintaining a detection device, such as a reading beam, as nearly as possible centered with respect to an information track, such as an optical track on a video recording disc. In each of the embodiments disclosed, circuitry is provided to process a signal obtained from the reading beam, to obtain timing signals indicative of transitions of the beam across noncentral switching lines parallel with the track. In one embodiment, a constant-magnitude acceleration signal is applied to a beam position transducer, and is reversed in polarity each time a switching line is crossed after first crossing the centerline. In another embodiment, the polarity of the constant-magnitude acceleration signal is reversed after crossing a switching line a second time and after applying an additional acceleration impulse of relatively short duration.

Abstract: A numerically controlled stitching machine tool comprises a head and a ta movable in relation to each other along two coordinate axes. The head is provided with a stitching needle and an optical follower placed in an invariable position in relation to the needle and receives the image of a drawing of the pattern when the drawing is placed on the table. The machine comprises, for each coordinate axis, a motor for moving the head and the table in relation to each other along that axis, transducer means for supplying an electrical signal whose amplitude depends on the movement along this axis, for A/D conversion and non-volatile storage, means for controlling the motor from the stored signals bringing into action said transducer and conversion means.

Abstract: A photoelectric transducer (14) produces first and second periodic signals (A), (B) which are 90.degree. out of phase with each other in response to rotation of a servo motor shaft (12a). The first and second signals (A), (B) are differentiated, directly full wave rectified and summed to produce a velocity signal (Vw+), (Vw-) having a magnitude proportional to the rotational velocity of the shaft (12a). The peaks of the first and second signals (A), (B) are detected to produce a reference signal (Vr) having a magnitude corresponding thereto. The magnitude of the reference signal (Vr) is reduced in accordance with the difference between the present position of the shaft (12a) and a command position to produce a velocity command signal (Vc+), (Vc-). The velocity signal (Vw+), (Vw-) is compared with the velocity command signal (Vc+), (Vc-) to produce a drive signal corresponding to the difference therebetween which is applied to the motor (12). Fluctations in the amplitude, D.C.

Abstract: An optical shaft encoder system for measuring electrically powered motor shaft speed, including a system for increasing the sinosoidal encoder output waveforms by a multiplication factor, converting the product of the multiplied waveforms to square waves, comparing the waveforms to a reference waveform and generating a correction signal which is fed back to the motor through servo circuitry, thereby correcting errors in motor shaft rotational speed.

Abstract: An adaptive position control system including X, Y and .theta. stages and their associated positioning and motion detection apparatus, position detection apparatus for detecting the position of the stages relative to a fixed reference, X and Y position control subsystems responsive to signals developed by the motion and position detection apparatus and operative to generate coarse mode and precision mode drive signals for application to the X and Y stage positioning apparatus, X and Y adjust subsystems for enabling adjustment of the position detection apparatus, and a .theta. adjust subsystem operative in a coarse mode and precision mode for adjusting of the angular orientation of the .theta. stage. Operator control input to the various subsystems is accomplished by means of a joystick control mechanism and central processing unit.

Abstract: A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.

Abstract: System for accurately positioning an article transfer assembly in a preselected one of several positions in at least one of a horizontal and a vertical path of movement by remotely controlling the assembly by way of a digital position reader unit. A belt control arrangement extends parallel to the paths of movement of the assembly and is provided with a series of mutually separate and locally disposed position-defining control elements, a corresponding series of mutually separate and locally disposed position-indicating control elements as well as a corresponding series of mutually separate and locally disposed locking elements. A carrier arrangement is combined with the assembly and displaceably engages the control arrangement by way of rollers. The carrier arrangement is provided with search devices adapted to cooperate with the position-defining control elements and with the position-indicating control elements and with a locking device adapted to cooperate with the locking elements.

Abstract: A motor control circuit of the Wheatstone bridge type is described for driving a direct current motor, selectively, in one direction or the other for the general purpose of automatically setting the diaphragm of a photographic camera in accordance with the light impinging on a photo-responsive element.

Abstract: Method and device for servo-controlling the distance of an object from a transiting surface to be followed by said object and capable of reflecting microwaves, by exploiting a control signal, wherein a radiating unit fast with said object provides directive microwave radiation and a symmetrical detector compares the phases of the radiated microwaves and the reflected microwaves, said detector providing a control signal to a servo-control circuit. The device is namely intended to automatic metal-welding machines in which the welding member forms said object and a metal workpiece forms the reflecting surface to be followed at a predetermined distance by said welding member.

Abstract: A device for manually controlling movement of a pickup arm in an automatic record player, comprising: a manually movable manipulation member; a detecting unit including at least one light-emitting element and at least two light-receiving elements disposed to receive the beam of light emitted from the light-emitting element to detect the amount and direction of a movement of the manipulation member and to generate a corresponding signal; control circuitry receiving this signal to generate an output corresponding to the direction and the amount of the movement of the manipulation member; and a driving unit for causing linear parallel movement of the pickup arm radially of a record disk and actuated by the output of the control circuitry to move this pickup arm in a direction and amount of movement corresponding to those of the manipulation member.

Abstract: Apparatus and method for detecting the movement of a control device (such as a tuning knob) for controlling the input to a controlled device (such as a frequency synthesizer or display) operating in discrete or digital steps. The rotational direction of a single tuning device such as a "tuning" knob causes an increase or decrease of the frequency. The rate of movement of the positioning device determines frequency bandswitching in differing degrees of coarse to fine tuning modes. The utilization of rotational direction and rate of the device provides a single control for all tuning functions.The apparatus and method is useful in both open and closed (servo) loop systems.

Abstract: A method for automatically controlling the position of small objects, comprises the steps of moving the object to cause at least a portion of an optical image of the object to be imaged on a photoelectric array which is placed on an image formation plane; sequentially detecting outputs by scanning photoelectric converting elements constituting the photoelectric array; counting, in a digital fashion, the position data of the object based on the above-mentioned outputs to deliver a correction signal for moving the object to a predetermined position; moving the object to a predetermined position according to the correction signal; and checking the position of the object by detecting outputs of respective photoelectric converting elements after completion of the above-mentioned movement step and calculating the positional data of the object.

Abstract: A table positioning apparatus suitable for use in an electron beam exposure system. A movable table holds a wafer or other work piece. The table is driven by a motor in response to a motor drive signal to position the table at different locations. An optical position measuring transducer is located in fixed relation to the table to establish a reference position for the table in a local region. The transducer provides a position signal as a function of the table position in the local region. An amplifier is provided which is responsive to the position signal to produce a servo signal. A motor drive circuit provides the motor drive signal for driving the motor in response to the servo signal so that the table is driven to the reference position. At the reference position, a reset signal is provided to reset interferometers in both X and Y axes.

Abstract: Mounted upon a servo-motor-driven longitudinally-reciprocable X-axis carriage is a servo-motor-driven laterally-reciprocable Y-axis carriage carrying an air cylinder with a vertically-reciprocable and rotatable piston rod. Mounted atop the piston rod is a fixed horizontal arm carrying a rotary actuator and a reciprocating motor respectively rotating and reciprocating a movable horizontal arm mounted on the fixed arm. Also mounted on said fixed arm and rotatable by a stepping motor is a horizontal narrow-angle video camera with high resolving power. An inclined reflector mounted on the outer end of said movable arm reflects into the horizontal camera light rays from articles underneath on a work carrier. A stationary vertical overhead wide angle video camera of lower resolving power is fixedly mounted above said work carrier and focussed thereupon.

Abstract: A positioning motor is energized by an actuating signal which includes a component proportional to, and another component proportional to the time-derivative of the output signal of a displacement transducer. The displacement transducer includes a plurality of light detectors. A synchronizing structure coupled to the motor moves through the light paths of the light detectors, causing each to generate a respective one of a plurality of mutually phase-shifted first signal components. Signal-processing circuitry derives from the first signal components second signal components which are phase-shifted relative to the first signal components, and combines the first and second signal components to form the transducer output signal.

Abstract: An apparatus to produce accurately limited angular or pivotal movements of a shaft of a DC motor with a control circuit to supply appropriate signals to control the operation thereof. Position indicators are provided to detect the shaft position and a second indicator is located to detect a rearward pivot position. Means are provided to establish a direction signal to indicate direction of rotation of the shaft, and the direction signal means and the position indicators produce outputs which are connected to the control circuit. The DC motor has a motor drive which receives signals from the control circuit during movement of the motor between forward and rearward pivot positions. The control circuit produces, first, an acceleration current and then a deceleration and finally a correction current with the current dropping to "zero" when the desired angular position has been reached by the shaft.

Abstract: The suspension of movable system instruments, for example, a galvanometer, introduces elastic reset torques upon deflection. To compensate for such torques and render the apparatus essentially independent of the deflection torques, an opto-electronic device provides an output signal representative of the deflection which is combined with the deflection voltage applied to the galvanometer to at least in part compensate for the reset torque introduced by the moving system suspension.