Abstract: Provided is a crane that is capable of effectively suppressing oscillation related to the pendulum resonance frequency generated in a suspended load on the basis of the suspended length of a wire rope. The crane 1 calculates a suspended load oscillation resonance frequency ?x(n) determined on the basis of the suspended length L(n) of a wire rope (14·16), and generates a control signal C(n) for an actuator according to an arbitrarily defined operation signal, and, on the basis of the resonance frequency ?x(n), generates from the control signal C(n) a filtering control signal Cd(n) for the actuator in which a frequency component in an arbitrarily defined frequency range is attenuated by an arbitrarily defined percentage. The frequency range of the attenuated frequency component and/or the percentage of attenuation is altered on the basis of the suspended length L(n) of the wire rope (14·16).

Abstract: A crane calculates the resonance frequency of the fluctuation of a suspended load determined from the hanging length of a main wire rope or a sub wire rope, generates a control signal for actuators, in accordance with the operation of a turning operation tool, a hoisting operation tool and the like, and generates a filtering control signal for the actuators in which a frequency component in any frequency range has been attenuated from the control signal at any ratio in reference to the resonance frequency. When the actuators are controlled by the operation of the respective operation tool and when the actuators are controlled regardless of the operation of the respective operation tool, the frequency range to be attenuated and the attenuation ratio are switched to different settings.

Abstract: A method of operating a multi-functional limb movement auxiliary device comprising a plurality of actuators configured to move, upon activation, limb movement auxiliary device members in at least two independent degrees of freedom, a bio-signal sensing unit that is configured to acquire bio-signals indicative of motor activity, a control unit configured to receive and evaluate the acquired bio-signals, the method comprising steps of acquiring bio-signals from the user of the limb movement auxiliary device, applying a novelty detection method (ND) for comparing digitally converted, acquired bio-signals with calibration bio-signals, and, based on a result of the comparison, for assigning a similarity measure to the acquired, digitally converted bio-signals, applying at least one sequential estimator (SEQ-E) to the acquired, digitally converted bio-signals, if the assigned similarity measure is equal to or larger than a pre-determined threshold value, applying at least one simultaneous estimator (SIM-E) to th

Abstract: An improved system and method for tuning a motor controller is disclosed. The improved system and method for tuning a motor controller adjusts controller gains and filter settings in tandem to achieve a desired level of performance. A user terminal is in communication with a motor controller and reads the existing controller gains from the motor controller. The user terminal displays the existing controller gains and at least one user selectable object for adjusting the controller gains. A user adjusts the user selectable object to adjust the controller gains in tandem. The controller gains are adjusted responsive to the user input while maintaining existing relationships between controller gains. The user terminal writes the adjusted values of the gains to the motor controller.

Abstract: A water heating system having a system inlet pipe (1.002), a hot water delivery pipe (1.003) and a hot water return pipe (1.006) connected to a building hot water distribution network (1.024); the water heating system including one or more water heaters (1.001), the or each water heater having a heater inlet (1.022) and a heater outlet (1.023), a hot water return pipe (1.006) connected between the system inlet and delivery outlet via the building hot water distribution network to form a close loop hot water supply-return circuit; a pump (1.005) connected to circulate water through the hot water supply-return circuit whereby the pump can circulate water through one or more of the water heaters; a valve means (1.007) a first non-return valve adapted to prevent inlet water (water delivered to the system inlet) from flowing into the hot water return pipe or the building hot water distribution network.

Abstract: A data processor system for monitoring a complex system, the processor system configured to receive a plurality of pieces of state information and to merge at least the pieces of state information into a piece of failure information, at least one of the pieces of state information being associated with a confidence flag, and the piece of failure information also being associated with a confidence flag. The system performs the merging by implementing a fuzzy logic technique to produce the piece of failure information while taking account of the respective confidence flag of the pieces of state information and to produce the confidence flag associated with the failure information.

Abstract: An optochemical sensing device has source that emits radiation of a first and a second predetermined intensity, a detector, and a sensitive element that comprises a signal substance. To measure an analyte in a measurement medium, the sensitive element is contacted with the analyte. A first raw signal, which is dependent on the analyte content is obtained by exciting the signal substance with radiation of the first predetermined intensity. At a later time, a second raw signal is also obtained. A comparison of the raw signals yields a comparison value, which is compared against a predetermined limit value. If the comparison value exceeds the limit value, the radiation source is set at the first intensity. If the comparison value is smaller than the limit value, the radiation source is set at the lower second intensity. Using the lower radiation intensity prolongs the life of the sensitive element.

Abstract: A sensing system includes a filter construction module that constructs a high pass filter for filtering sensor values indicative of a process variable, the filter construction module setting values for parameters of the filter based on a temperature value indicative of a temperature of the sensor that produced the sensor values.

Abstract: A method of diagnosing an adaptive process control loop includes measuring process control loop signal data, generating a plurality of process control loop parameters from the process loop signal data and evaluating a condition of the adaptive process control loop from one or more of the plurality of process control loop parameters. The process control loop data is generated as a result of a normal operation of one or more process control devices within the adaptive process control loop when the adaptive process control loop is connected on-line within a process control environment. A self-diagnostic process control loop includes a diagnostic tool adapted to receive a diagnostic index pertaining to a process control loop parameter for a plurality of components of the process control loop and for the complete process control loop. Each diagnostic index is generated from signal data by a corresponding index computation tool.

Abstract: A method and apparatus for compensating a bias voltage at the wafer by measuring RF voltage signals in RF driven plasma including at least an electrostatic, chuck (ESC), a capacitive divider, a signal processing and signal conditioning network is disclosed. The bias compensation device includes a capacitive divider to detect the RF voltage at the ESC, a signal conditioning network for the purpose of filtering specific RF signals of interests, and a signal processing unit for computing the DC wafer potential from the filtered RF signals.

Abstract: A device and method to adapt a model in a underdetermined adaptive system that provides an output in response to an input. A controller provides parameters to the model in a transceiver system, composed of linearizers, equalizers, or estimators as a function of an error signal. The controller and the model parameters are manipulated to allow agnosticism with respect to input signals or model complexity, enabling robust operation and efficient implementation.

Abstract: A control system for using a predictive control with a control process having a time delay includes an adaptive feedback controller and a predictor. The predictor uses at least an adaptively updated control parameter from the adaptive feedback controller to predict the output of the control process during the time delay. The control system further includes a filter that dampens the rate of change of the adaptively updated control parameter provided to the predictor from the adaptive feedback controller to slow the adaptation of the predictor relative to the adaptation of the adaptive feedback controller.

Abstract: A control system for optimizing an oxy-fuel power plant comprises an optimizer in communication with the oxy-fuel power plant; the oxy-fuel power plant being operative to recycle carbon dioxide from a flue gas stream to a boiler; a control platform; the control platform being operative to control the oxy-fuel power plant; and a simulator; the simulator being operative to simulate performance of the oxy-fuel power plant.

Abstract: A repetitive controller, a control method thereof and a feedback control system are disclosed. The repetitive controller includes an internal model section, a periodic delay module and a compensation module. An input quantity is input into the repetitive controller via an input terminal of the internal model section; the internal model section, the periodic delay module and the compensation module are connected in series. The repetitive controller further includes a particular frequency selection and passing module, connected in series with the internal model section, the periodic delay module and the compensation module or configured on a forward path of the internal model section. In the repetitive controller of the disclosure, a particular frequency selection and passing module is incorporated such that only the harmonic at the selected frequency are filtered out, thereby realizing the function of removing the harmonic at the particular frequency.

Abstract: A power converter system is provided, comprising a plant having a plant input and a plant output; and a plant identification filter that receives the plant input and the plant output, and estimates the values of poles and zeros of the plant, wherein the plant identification filter updates the estimates of the poles and zeros, based upon the plant input and the plant output, beginning from an initial state; and a rate at which the plant identification filter updates the estimates of the values of the poles and zeros is slower than a rate at which the plant input and the plant output are received by the plant identification filter.

Abstract: The present application provides an adaptive control system for controlling a plant in particular a DC-DC power converter. The control system has two controllers of differing characteristics. The output of the individual controllers H0 and H1 are combined together to provide a combined control signal H to the plant, where H=?H1+(1??)H0 and where the adaptive control system is tuned by adjusting the value of ? between 0 and 1 to find an optimum control position.

Abstract: One or more techniques are provided for the sharing of variable trajectories between multiple controllers in a control system. In general, the present technique is based upon the sharing of predicted desired variable trajectories between multiple controllers requiring a common input variable. In one embodiment, a common input variable is shared between two controllers, wherein one controller is tuned to have dominant control with regard to the shared variable. Each controller determines and communicates their own desired trajectory for the shared variable to the other controller and in doing so, the constraints associated with each controller are shared and honored by the other controller. Based on the communicated trajectories, the dominant controller may exercise control over the shared variable, thus improving overall process control.

Abstract: In a case where a position command path for a control position of a load 5 that is equivalent to a moving object is set by issuing a position command Rc(z), a gain for one of a high-frequency component, a specified frequency, and a specified frequency width is constrained. This means that a resonant frequency can be constrained, and that after the position command Rc(z) arrives at a target position, a position detection signal Y(z) can also arrive at the target position in a set number of steps. It is therefore possible to perform positioning at high speed and with high precision by constraining a resonance mode of a mechanism that includes the moving object, and a feed-forward control can be performed that meets target positioning times that are set for various types of operating patterns.

Abstract: A system for a providing a multi-rate digital low pass filter that attenuates high frequency resonances in a control signal. The filter described by a transfer function having a phase-advanced factor (or an approximation of phase-advanced factor) and a low pass filtering function; either cancels or avoids an unstable pole in the phase advanced factor at z=?1.

Abstract: System and method for data mining and feature tracking for fab-wide prediction and control are described. One embodiment is a system comprising a database for storing raw wafer manufacturing data; a data mining module for processing the raw wafer manufacturing data to select the best data therefrom in accordance with at least one of a plurality of knowledge-, statistic-, and effect-based processes; and a feature tracking module associated with the data mining module and comprising a self-learning model wherein a sensitivity of the self-learning model is dynamically tuned to meet real-time production circumstances, the feature tracking module receiving the selected data from the data mining module and generating prediction and control data therefrom; wherein the prediction and control data are used to control future processes in the wafer fabrication facility.

Abstract: A quality regulating apparatus and method is disclosed which operates on a product stream having an incoming product stream quality level so that an outgoing product stream quality level provided by the apparatus follows a target quality level so that it is better than the target quality level providing a maximum yield. The apparatus includes a conveying device, a product stream imager, an inspection engine, a routing engine, and an object diverting station. In operation, the inspection engine and routing engine cooperate in a manner so that objects classified as defective are intentionally passed to the output product stream when their inclusion maintains the quality level of the first output product stream at a level that is better than or equal to the target quality level.

Abstract: A method and a device for robust rejection of the periodic disturbances in a motor-position control structure of the RST type, wherein the assembly including the motor, the position sensor, the element for computing the functions 1/So(z?1) and Ro(z?1), in a loop, is called central controller. Within the framework of the invention, to the central controller are added two additional computing elements, the first one being an estimator block E(z?1) and the second one a modifier block Q(z?1), as well as an additional loop, the estimator block E(z?1) allowing a load disturbance estimation signal {circumflex over (v)}(t) to be computed, the modifier block Q(z?1) receiving the load disturbance estimation signal {circumflex over (v)}(t) as an input, to produce a modified signal, which is applied to a negative input of an additional adder arranged upstream from the element for computing the function 1/So(z?1) and then forming the additional loop, the modifier block having a variable transfer function.

Abstract: A system for controlling a motorized track light system constrained to travel along a track has a control unit coupled to a motor that causes the track light system to move along the track, a plurality of stop sensors strategically disposed along the track, a sensor activation device located on the track light system, the sensor activation device positioned to interface with the stop sensors, and a light sensor for detecting ambient light of a preset level. The system detects a preset level of ambient light, initiating power to the motor of the track light system, moving the lights along the track until the activation device interfaces with a first of the plurality of stop sensors, stopping movement of the track light system along the track for a preset period of time, and at the end of the preset time period, the electrical power is restored to the motor moving the track light assembly along the track to the next of the plurality of stop sensors.

Abstract: A system for monitoring an industrial process and taking action based on the results of process monitoring. Actions taken may include process control, paging, voicemail, and input for e-enterprise systems. The system includes an input module for receiving a plurality of parameters from a process for manufacture of a substance or object. The system also includes a library module. The library module includes a plurality of computer aided processes. Any one of the computer aided processes is capable of using each of the plurality of parameters to compare at least two of the plurality of parameters against a training set of parameters. The training set of parameters is generally predetermined. The computer aided process is also capable of determining if the at least two of the plurality of parameters are within a predetermined range of the training set of parameters. Additionally, the system includes an output module for outputting a result based upon the training set and the plurality of parameters.

Abstract: A control system is provided for controlling a transducer array. The control system includes a plurality of sparse filters and integrators. The control system can be used to separate signals from a plurality of sources or to generate complex signal patterns that combine and map to different spatial regions.

Abstract: The method for generating an integrated guidance law for aerodynamic missiles uses a strength Pareto evolutionary algorithm (SPEA)-based approach for generating an integrated fuzzy guidance law, which includes three separate fuzzy controllers. Each of these fuzzy controllers is activated in a unique region of missile interception. The distribution of membership functions and the associated rules are obtained by solving a nonlinear constrained multi-objective optimization problem in which final time, energy consumption, and miss distance are treated as competing objectives. A Tabu search is utilized to build a library of initial feasible solutions for the multi-objective optimization algorithm. Additionally, a hierarchical clustering technique is utilized to provide the decision maker with a representative and manageable Pareto-optimal set without destroying the characteristics of the trade-off front. A fuzzy-based system is employed to extract the best compromise solution over the trade-off curve.

Abstract: A system for a providing a multi-rate digital low pass filter that attenuates high frequency resonances in a control signal. The filter described by a transfer function having a phase-advanced factor (or an approximation of phase-advanced factor) and a low pass filtering function; either cancels or avoids an unstable pole in the phase advanced factor at z=?1.

Abstract: Provided are a method and apparatus for controlling a sound field through an array speaker. The method includes calculating a coefficient of a filter that controls sound pressure of an input signal, based on a sound pressure ratio of a suppression area that suppresses sound emitted from an array speaker and an emphasis area that emphasizes the sound, and sound pressure efficiency in the emphasis area, generating a plurality of output signals that focuses the sound to the emphasis area by filtering the input signal based on the calculated coefficient of the filter, and outputting a sound field controlled sound based on the generated plurality of output signals. Accordingly, a listener in a predetermined direction and distance from the array speaker can clearly hear sound, without wearing an earphone or a headset so as to focus the sound only to the listener.

Abstract: Complex filters may be used to achieve compensation of a plant, corresponding for example to a power regulator or point-of-load (POL) regulator. Digital filter coefficients may be mapped to analogous poles and zeros, or they may be mapped to values of the quality factor (Q) of the output, frequency, and gain. The plant may be observed and characterized using a network analyzer to generate the Bode plot (or Nyquist plot) for the plant. The digital filter coefficients may be mapped to features that may be identified on the Bode plot (or Nyquist plot) to easily correlate characteristics of the digital filter or digital compensator to the plant characteristics. The mapped features may be adjusted, for example by a user, either manually or by executing one or more optimization algorithms, to achieve the desired results relative to the Bode plot (or Nyquist plot).

Abstract: A method and a system for controlling a crane drive unit so as to suppress sway of a load suspended by a rope of a crane, which sway occurs when the load has been transported from a first position to a second position, the control being made by operating a controller having a filter unit by using a feedforward control program.

Abstract: This device for controlling at least one operating variable of a regulated system comprising: a filter module for filtering at least one setpoint input to the control device, the module using a first order integrator; and a correction module for correcting the variable by servo-control, the module taking account of a measurement of the variable and of the setpoint as filtered by the filter module in order to generate at least one command for the system; a control module suitable for generating a gain control factor ? on the basis of at least one parameter of the system and of an operating limit value associated with the parameter; and weighting means for weighting the gain of the filter module as a function of the factor and of the residue between the setpoint and its filtered value.

Abstract: A method and apparatus for data analysis according to various aspects of the present invention is configured to automatically select one or more outlier identification algorithms for identifying statistical outliers in test data for components.

Abstract: A process control apparatus for controlling a control target includes, but is not limited to, first and second control units. The first control unit is designed in a design environment unspecifying any period of disturbance. The first control unit performs a feedback control to the control target by using a setting value of the control target and a measured value of the control target. The first control unit is included in a feedback loop. The second control unit is also included in the feedback loop. The second control unit is designed by using an internal model principle. The second control unit rejects the disturbance, which is applied to the feedback loop, by using the measured value of the control target.

Abstract: A robot localization system is provided. The robot localization includes a robot, which moves within a predetermined space and performs predetermined tasks, and a docking station corresponding to a home position of the robot. The docking station includes a first transmitting unit, which transmits a sound wave to detect a position of the robot; and a second transmitting unit, which transmits a synchronizing signal right when the sound wave is transmitted.

Abstract: Disclosed is a multi-phase pulse width modulated voltage regulator and method in which transient voltage excursions or deviations that exceed the load line voltage by more than a pre-determined amount are detected by an ATR circuit and a correction signal is applied. The correction signal is in the form of asynchronous pulses and the number of such pulses is a function of the magnitude of the voltage excursion as determined by the number of thresholds that are exceeded. Also disclosed is an adaptive voltage positioning (AVP) circuit and method for early detection of a transient event by sensing voltage changes at the load and adjusting the target voltage with pre-determined current values prior to the time that ATR event changes in the current at the load are detected.

Abstract: A method and system may operate to receive a first data from a sensor of a controlled device via a wireless network at a first time, transmit the first data to a controller system, receive a second data from the sensor of the controlled device via the wireless network at a second time, transmit the second data to the controller system, determine that a third data has not been received prior to a predetermined time period, or that the third data has been received prior to the predetermined time period and the third data is outside of a determined range of values, calculate a fourth data based on the first data and the second data, and transmit the fourth data to the controller system at a third time.

Abstract: The object is to aim at the reduction in the influence of noises in an output of an AE sensor in a working machine. In a working system comprising a working device for working a work W by causing a tool 14 to come into contact work W, an AE sensor 21, and an AE signal processing section 22 for processing an AE signal output from the AE sensor, AE signal processing section 22 comprises an A/D converter 33 for converting an AE signal into a digital signal, a frequency analysis section 34 for calculating the frequency characteristics of a digital AE signal, storage sections 35, 37 for storing the frequency characteristics when the tool is not in contact with the work or tool dresser as non-contact frequency characteristics, and a difference calculation section 35 for calculating a difference between the frequency characteristics of the detected digital AE signal and the non-contact frequency characteristics.

Abstract: A system for diagnosing the quality of a reagent solution may comprise a reagent solution source for supplying the reagent solution to an emissions catalyst of an internal combustion engine. Means may be provided for determining a quality value corresponding to the quality of the reagent solution. A first filter may receive the quality value and produce a first filtered quality value, and a first comparator may compare the filtered quality value to a threshold and produce a fault value if the first filtered quality value crosses the threshold. Alternatively or additionally, a second filter may receive the quality value and produce a second filtered quality value. A second comparator may compare a difference between the first and second filtered quality values to another threshold and produce another fault value if the difference crosses that threshold.

Abstract: A process for the automatic control of the thickness of extruded film lowers the deviations in the thickness of the film more quickly after the start of the extrusion process. The process includes the measurement of the thickness profile of the film just extruded by means of a thickness-measuring probe. The thickness-measuring probe is moved along the surface of the film substantially perpendicular to the conveying direction of the extruded film. The thickness-measuring probe records a thickness profile of the film for each measuring cycle at least over parts of the expansion of the film perpendicular to its conveying direction. While providing statistical values in relation to older measured values, the latest measured values during a predetermined time-frame at the start of the extrusion process are more heavily weighted by a computer than those measured during the normal operation.

Abstract: A device for diagnosing operation of an industrial process control or monitoring system includes an input configured to receive an input related to a process signal. A first statistical parameter module provides a first statistical parameter output related to a statistical parameter of the process signal. A filter provides a filter output related to a filtered value of the process signal. A second statistical parameter module provides a second statistical parameter output related to a statistical parameter of the filter output. A diagnostic module diagnoses operation of the industrial process based upon the first and second statistical parameters.

Abstract: The present invention provides a new set of algorithmic solutions to accommodate track inaccuracy information in track databases. Navigation and measurement aiding processes are defined by a stochastic mode relative to a moving rail frame defined so that it is aligned with the heading of the compensated track database at the current along track-position. Filtering generates long and short wavelength track alignment disturbances commensurate with track grade to compensate for track database errors; a stochastic error model is defined as the difference between the deterministic implementation and the actual stochastic processes Bayesian estimation of the error variables is implemented via a digital Kalman filter with the navigation, database, and measurement errors removed by subtracting the filter estimates.

Abstract: A projection is associated with a first signal and a second signal. The second signal includes a first portion associated with the first signal and a second portion not associated with the first signal. The projection at least substantially separates the first portion of the second signal from the second portion of the second signal. One or more parameters of a model are identified using at least a portion of the projection. The model associates the first signal and the first portion of the second signal.

Abstract: In the field of electronic or computerized control apparatuses, known methods of compensating for disturbance signals rely on less than ideal analytical or empirical models. There is provided a controller (200) or method of controlling which observes and learns the correlation between various measured signals and automatically learns how to control the apparatus.

Abstract: A method and a system for controlling a crane drive unit so as to suppress sway of a load suspended by a rope of a crane, which sway occurs when the load has been transported from a first position to a second position, the control being made by operating a controller having a filter unit by using a feedforward control program.

Abstract: A computer system for compressing synthetic aperture radar (SAR) images includes a database for storing SAR images to be compressed, and a processor for compressing a SAR image from the database. The compressing includes applying an anisotropic diffusion algorithm to the SAR image, and compressing the SAR image after applying the anisotropic diffusion algorithm thereto. Applying the anisotropic diffusion algorithm includes determining noise in the SAR, selecting a noise threshold for the SAR image based on the determined noise, and mathematically adjusting the anisotropic diffusion algorithm based on the selected noise threshold.

Abstract: A matrix includes samples associated with a first signal and samples associated with a second signal. The second signal includes a first portion associated with the first signal and a second portion associated with at least one disturbance, such as white noise or colored noise. A projection of the matrix is produced using canonical QR-decomposition. Canonical QR-decomposition of the matrix produces an orthogonal matrix and an upper triangular matrix, where each value in the diagonal of the upper triangular matrix is greater than or equal to zero. The projection at least substantially separates the first portion of the second signal from the second portion of the second signal.

Abstract: In the field of electronic or computerized control apparatuses, known methods of compensating for disturbance signals rely on less than ideal analytical or empirical models. There is provided a controller (200) or method of controlling which observes and learns the correlation between various measured signals and automatically learns how to control the apparatus.

Abstract: Systems and methods have been developed for reclaiming water contaminated with the expected range of contaminants typically associated with produced water in order to produce a treated water having a quality adequate for reuse as a fracturing water. The system includes anaerobically digesting the contaminated water, followed by aerating the water to enhance biological digestion. After aeration, the water is separated using a flotation operation that effectively removes the spent friction reducing agents and allows the treated water to be reclaimed and reused as fracturing water, even though it retains levels of contaminants, including boron and methanol, that would prevent its discharge to the environment under existing standards. The treated water has had a sufficient amount of the gellation-inhibiting contaminants, such as acrylamide friction reducing compounds, removed to allow the treated water to be an economically viable fracturing water.

Abstract: A converter unit connected to a monitor apparatus for monitoring and controlling a plurality of air conditioners, including: PAC transmission software for transmitting a setting data from the monitor apparatus regarding a running start/stop state, a running node, an air quality and a temperature, respectively of the air conditioners, to a transmission path, and for receiving running data regarding a temperature and a pressure of a component during the refrigerating cycle from the transmission path; transmission software for receiving the setting data from the monitor apparatus and transmitting the running data to the monitor apparatus; and a converter to convert the running data for the PAC transmission software to a running data for the transmission software, and to convert the setting data for the transmission software to a setting data for the PAC transmission software, respectively, wherein the running data is collected from the control message at a predetermined interval, and the collected running data i

Abstract: An injection molding machine comprises a pre-pressure addition means 2 adding a pre-pressure B acting in the opposite direction of a molding material pressure A received by a screw 1 to a detection means 3 and/or the screw 1, the detection means 3 detecting the axial pressures A and B of the screw, and a screw movement control means 4 controlling the axial pressure based on a different between the pre-pressure B and the molding material pressure A, wherein the pre-pressure addition means 2 is made non-contact with the direction means 3, a forward and backward driving motor 17 is disposed adjacent to a heating cylinder 10, and a screw connector 21 at the rear end of the screw 1 is spline-connected inside a rotating rotor of a screw rotating motor 12. According to the machine, the molding material pressure received by the screw can be accurately detected without being affected by the wear of the machine so as to properly control the axial pressure of the screw and to make the machine compact.