Locomotive governor control
AssigneeCaterpillar Tractor Co.
InventorsWalter E. Earleson, Dennis M. King, Michael E. Moncelle
Life of this patent
Estimating the term…
Abstract
A digital processor implemented electronic governor for engine-generator units including a first control loop for producing a speed error and controlling fuel delivery setting as a function thereof and a second control loop for detecting rack error and producing a field excitation current control signal as a function thereof. Power dips and overruns are voided by modifying rack error as a function of engine acceleration. Means are provided for developing speed errors and rack control signals despite a breakdown in the rack position indicator. Open loop lower power setting controls are provided. Wheel-slip control, power limiting and variable acceleration functions are provided.
Claims22
A control system for an engine-generator unit (10,14) of the type having a fuel delivery control (12) and a field current controller (28), comprising:
- a power selector (22) having a plurality of selectable power settings;
- speed calculator means (24) for deriving a speed error signal as a function of the power selector setting and the actual engine speed and for applying an output which is a function of the speed error signal to the fuel delivery controller (12);
- and
- rack calculator means (26) for deriving a rack error signal as a function of actual engine speed and actual fuel delivery controller setting and for applying an output to the field current controller (28) which is a function of the rack error signal.
A method of controlling the operation of an engine-generator unit of the type having a rack position control and a field current control comprising the steps of
- (a) generating a power setting signal
- (b) developing a desired speed signal from the power setting signal
- (c) developing a speed control error e.sub.N from a comparison of the desired speed signal and actual speed
- (d) setting the rack control as a complex function of e.sub.N
- (e) developing a desired rack signal from the actual speed;
- (f) developing a rack error e.sub.R from a comparison of desired rack and actual rack position;
- and
- (g) setting field current as a complex function of e.sub.R.
A control system for a combination engine-load unit (10,14) wherein the power consumption of the load is variable according to a signal applied to a control input of a load controller (28), and wherein the engine is of the type having a fuel delivery control (12) comprising:
- a power selector (22) having a plurality of selectable power settings;
- engine speed calculator means for deriving a speed error signal as a function of the power selector setting and the actual engine speed and for applying an output which is a function of the speed error signal to the fuel delivery controller (12);
- and,
- rack calculator means (26) for deriving a rack error signal as a function of actual engine speed and actual fuel delivery controller setting and for applying a control signal to the control input of the variable load controller (28) which is a function of the rack error signal.
Dependencies are inferred from the claim text.