摘要:
A control system for controlling displacement of a member in a glassware forming machine. A pneumatic piston drives the member and is controlled by a computer which defines a motion profile. The difference, at any moment, between the demanded position and the actual position is determined and an error signal is defined based on the difference signal and the momentary velocity and acceleration.
摘要:
An integrated compliance electrohydraulic servovalve system connected to a load such as a simulated living being to provide more realistic movement thereto. The system includes a pressure transducer for sensing the pressure appearing at the output of the electrohydraulic servovalve and which is applied to an actuator connected to the load. The pressure as sensed is developed into a corresponding electrical signal which is used as a feed back signal to the drive motor of the electrohydraulic servovalve. The actuator position signal is also provided and is summed with the position command input signal to provide the command signal which is also summed with the pressure signal prior to application to the drive motor. The utilization of the pressure feed back signal provides compliance to the over all system resulting in a realistic movement of the simulated living being.
摘要:
A position control circuit having a demodulator with automatic tuning capability for use in an electro-hydraulic positioning system used to position a servo device. The position control circuit includes the demodulator, an analog to digital converter with an input voltage range, and a microcontroller. The demodulator has a gain and is operable to convert a feedback signal from the servo device to a position signal having a lower voltage value when the servo device is at its 0% position and an upper voltage value when the servo device is at its 100% position; the lower voltage value and upper voltage values being a function of the demodulator gain. Upon operator initiation, the microcontroller automatically calculates the largest value for the demodulator gain that results in the position signal from the demodulator having a lower voltage value within a lower voltage range and an upper voltage value within an upper voltage range, where the lower voltage range and the upper voltage range are within the input voltage range of the analog to digital converter.
摘要:
In a die casting machine that includes a shot cylinder having a ram for injecting metal into a die cavity, an electrohydraulic system for controlling operation of the shot cylinder includes an actuator coupled to the shot cylinder ram. A valve supplies hydraulic fluid to the actuator cylinder as a function of valve control signals. Microprocessor-based digital control electronics includes memory for storing a desired ram velocity profile as an incremental function of ram position. The control circuitry is responsive to signals from a sensor coupled to the actuator, indicative of position at the ram, for retrieving corresponding velocity signals from memory and supplying control signals to the valve as a function of such profile velocity signals. The control circuitry further includes facility for adjusting impact of the shot cylinder ram at the end of a cavity-filling stroke as a function of ram and actuator position and/or pressure, independently of the velocity/position profile, to reduce separation and flashing at the die cavity, and to reduce impact wear and fatigue on the overall die casting machine. A keyboard and associated operator display provide operator programmability and selection from a plurality of velocity/position profiles. The actuator and cylinder ram may be advanced in a manual mode of operation for adjustment and calibration proposes. A display associated with the keyboard graphically illustrates desired and actual velocity/position profiles during operation, together with a profile of actuator drive pressure verses position.
摘要:
An industrial robot and a control system therefor are described. The robot generally consists of a base member, a post member rotatably mounted on the base member, fluid actuated means for rotating the post member relative to the base member, an arm assembly mounted on the post member, means for performing a work function mounted on the arm assembly, fluid actuated means for operating the arm assembly and the work performing means and a system for controlling the operation of the fluid actuated means. A fluid reservoir is provided having a compartment in the post member, and fluid lines intercommunicate the reservoir and the aforementioned fluid actuated means. A motor driven pump mounted on the post member supplies fluid from the reservoir under pressure to the fluid actuated means under the control of electrically operable valves mounted on the post member for that purpose. A control system operates to control the aforementioned hydraulic system by sensing positions of the robot mechanism and comparing those sensed positions with desired positions, information concerning which is in a storage element. The desired and actual positions are compared in a first comparator for producing an error signal which forms a reference signal. The reference signal along with signals corresponding with the actual and desired positions are compared in a second comparator to produce a second error signal which ultimately causes the robot mechanism to move by the desired amount.
摘要:
An electronics for active cancellation of a pulsating flow with a flow signal noise reference. The electronics includes a signal processor configured to receive a flow signal from a flow sensor that is configured to measure a flow rate of the pulsating flow, generate a flow rate signal and a noise reference signal from the flow signal, and generate a cancelling signal from the noise reference signal. The electronics also includes a controller coupled to the signal processor and configured to determine a flow rate control signal. The electronics includes a signal generator communicatively coupled to the signal processor and the controller and configured to receive the flow rate control signal, generate a valve signal based on the flow rate control signal and the cancelling signal, and provide the valve signal to a valve to control flow rate and attenuate pulses of the pulsating flow of the fluid.
摘要:
A work machine to cut timber including a control system, a felling head, a hydraulic motor configured to adjust the position of the felling head, and a spool valve operatively connected to the hydraulic motor, the spool valve being configured to move the felling head responsively through operation of the hydraulic motor. A machine controller coupled to the operator controller and the spool valve executes stored program instructions to generate a first control signal responsive to an operator control signal provided by the operator controller, generate a second control signal as a function of the generated first control signal, adjust a position of the spool of the spool valve in response to a concurrent receipt of the first control signal and the second control signal by the first proportional control valve and the second proportional control valve to move the felling head through operation of the hydraulic motor.
摘要:
A closed loop control system for a pneumatic actuator using position and pressure feedback signals. The feedback signals are supplied to a microprocessor which successively generates a desired acceleration, a desired actuator force, a desired gas pressure, and a gas mass flow rate command for a gas flow controlling valve. The use of the gas flow rate as a control variable decouples pneumatic ronlinearities from the control loop. Nonlinear viscous friction, coulomb friction and load effects are decoupled from the control loop prior to the calculation of the desired pressure. An improved trajectory is achieved by employing a plurality of trajectory phases, including a velocity control phase.
摘要:
An automatic control including a memory is provided to be loaded with positional data for the automatic control of a cycle of motions of preferably a plurality of power members. The speed reading the data in and out is freely selectable. Accordingly programming a cycle of motions may be performed in a slow motion process, whereas the speed of reading out the data is selected such that an optimum operational speed is obtained. In addition to the automatic speed control a manual control is provided to interrupt the cycle motion of the automatic control to manually adjust the position or the power member. In returning to the automatic control the further cycle of motion is taken up again where it has been interrupted.
摘要:
A system and method for remotely measuring and linearizing flow characteristics, specifically velocity characteristics, of an electrohydraulic servo valve and actuator system. A plurality of raw command signals are generated in sequence, and corresponding motion data at the valve and load (including the actuator) are measured and stored. A linearized characteristic is then generated corresponding to the range of motions measured, and a look-up table is generated which relates raw command signals to command signals necessary to obtain the desired linear motion characteristics.