Abstract:
In order to be able with a linear adjusting arrangement, especially for adjusting the drive for a moved workpiece or a moved tool on a machine tool, to adjust a periodic command variable (w), if possible without any difference in adjustment, the adjuster (1) is to have at least one conjugated complex pair of pole positions on the imaginary axis (j omega ) or in the left half of the plane of co-ordinates ( sigma ,j omega ) of the complex variable (s) representing vibration damping, whose sum defined by its distance from the zero point of the system of co-ordinates ( sigma ,j omega ) is the same or approximately the same as the periodic frequency of the command variable (w). In addition, or alternatively, the adjuster (1) is to have, to stabilise a periodic disturbance variable (z) on the imaginary axis (j omega ) or in the left half of the plane of co-ordinates ( sigma ,j omega ) of the complex variable (s), at least one conjugated complex pair of pole positions whose sum defined by its distance from the zero point of the system of co-ordinates ( sigma ,j omega ) is the same or approximately the same as the periodic frequency of the disturbance variable (z). As an additional or alternative measure to stabilize a periodic disturbance variable (z), there may be, in the return branch for the adjustment value (x), a return component (3) which has on the imaginary axis (j omega ) or in the left half of the plane of co-ordinates ( sigma ,j omega ) of the complex variable (s), at least one conjugated complex pair of pole positions whose sum defined by its distance from the zero point of the system of co-ordinates ( sigma ,j omega ) is the same or approximately the same as the periodic frequency of the disturbance variable (z).
Abstract:
A condition control system for e. g. a boiler is responsive to a pressure (or temperature) signal PR to generate an on/off firing signal 22 and a firing rate signal 26, by a proportional control path (via 50) and an on/off path (51). The system operates in 2 modes: proportional (modulating), and cycling, determined by a limit switch signal LS. To minimize the cycling rate when cycling, the system is forced into the lowest fire rate when first fired up; the rate of change of pressure is sensed (at 86) and the signal LS changes the mode to proportional if the pressure falls (indicating that the low fire rate is inadequate). In the proportional mode, integral action (via 57) is used to adjustthe setpoint PSET (via 44) to reach a stable operating state. In the cycling mode, the setpoint PSET is adjusted in dependence on the duty ratio of the cycles.
Abstract:
The position control system has an integrating element (GC1) in the control loop of the machine tool, and a conpensator (CPS) for compensating for instability in the loop caused by the integrating element (GC1). Thus, the position deviation characteristic of the loop can be improved to give accurate position control.
Abstract:
Described is a novel technique and associated arrangement for determining the noise-free value of a system parameter (e.g., head position in a disk drive) which is time variable and (usually) has a noise component as detected. The technique involves processing the (as detected) noise-including value and passing it through "Second Order/ Summing" filter means. For instance, the technique is described as particularly useful with the "track-following servo" (part of the transducer positioning means) in a high density disk file (where track density is higher than usual) to secure superior head- displacement error values which are more noise-free. Thus, (see Figure 4), a pair of first values V 8 , V b are secured by detecting motor current sense voltage V i , integrating it with respect to time and passing the result through a pair of novel "second order filter" means - one hand-pass (F 1 ), the other low-pass (F 2 ); while also securing a third value V c by detecting position error (signal voltage, including noise components) in the usual manner and passing it through a "second order low-pass" filter F 3 ; then algebraically summing these to secure a relatively noise-free position error signal V xo Thus, the summing filter array gates the position-error voltage but attenuates the (mechanical) noise component (cf. filters F 2 , F 1 centered at w o - e.g., 600 Hz is satisfactory here). Such "second order" filters are novel in themselves, and particularly as so applied (most especially as so-used in such a servo system).
Abstract:
A novel technique and associated arrangement for determining the noise-free value of a system parameter which is time variable and has a noise component as detected. The technique involves processing the noise-including value and passing it through "Second Order/Summing" filter means (FF). The technique is particularly useful with the "track-following servo" in a high density disk file to secure superior head-displacement error values which are more noise-free. A pair of first values input to a summer (Sm) are secured by detecting motor current sense voltage (Vi) integrating it with respect to time and passing the result through a pair of novel "second order filter" means --one band-pass (F1), the other low-pass (F2); while also securing a third input to the summer (Sm) by detecting a position error signal voltage (Vxi), including noise components (M(s)) in the usual manner and passing it through a "second order low-pass" filter (F3); then algebraically summing these to secure a relatively noise-free position error signal (Vxo). Thus, the summing filter array gates the position-error voltage (Vxi) but attenuates the (mechanical) noise component (M(s)).
Abstract:
Real time servo control in a non-linear dynamic system (20) adjusts the energy applied to a prime mover (14) from a source (12) of the energy as a linear function of an error (22) between the measured load (16) characteristics and modelled load characteristic. The modelled load characteristics are linearized as a function of the initial conditions of the load (16) at the beginning of each cycle.
Abstract:
In a control system a characteristic quantity of a process (1) exhibits a periodic disturbance. A measuring system (2) generates a measuring signal (Vm) which represents the characteristic quantity. A control device controls the process in response to the measuring signal (Vm). To reduce the periodic disturbance, the control device (3) comprises a delay circuit (4) which delays an input signal (Vin) related to the measuring signal (Vm) by a time interval (T) having the length of a period (Tp) of the periodic disturbance. The control device (3) comprises an analysis circuit (6) for deriving an analysis signal (Va) which is indicative of a deviation between the period of the periodic disturbance and the delay time. By means of a control circuit (13) and an adapter circuit (7), the delay time (T) is set in dependence on the analysis signal (Va) to a value for which the analysis signal (Va) indicates that the delay time (T) is equal to the period (Tp). A correlation system can be used for deriving the analysis signal (Va).
Abstract:
The invention relates to a controlling device with PID control component by means of which a controller output value (u) can be obtained from the control difference (Xd), with an actuator (5) with correcting variable limitation forming a correcting variable (y) from the controller output value (u) and a switch (4) by means of which the control difference (Xd) is taken to the PID control component as a controller input value (r) if the correcting variable (y) determined by the controller output value (u) lies within its setting range and by means of which an auxiliary value (e) is taken to the PID control component if there would be an ideal limitless correcting variable owing to the control difference (Xd) outside the setting range. The auxiliary value (e) is determined in such a way that the correcting variable (y) still lies within its setting range. This prevents a rise in the I component if the reference value (y) lies within the limits concerned. The invention is used in controllers.
Abstract:
The invention relates to a process for determining a feedforward control (Gk) on a regulator output in a closed regulating circuit in which the effect of the interference (z) on the regulated value (y) is detected without reference to a feedforward control, which is at least approximately adjusted in such a way that it makes an alteration to the setting (y) occuring as a reaction to a change in the interference. The invention has the advantage that a first process component (P1), a transmission behaviour (Gz) of the interference (z) and an additional process value do not have to be known to determine the feedforward control (Gk). The invention is applied to regulators with feedforward control.