EP0153102A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Ground-working depth control system for a vehicle
Assignee: Deere and Co
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Filing: 1985-02-08
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Granted: —
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Expires: 2005-02-08
Abstract
Abstract A vehicle (10) pulls an implement (14) attached to a hitch (12) with a lift cylinder (24) actuating a rockshaft (22) to control implement working depth. A servo system (50) responds to a position command signal from an operator control (30), a signal from a control (34) selecting position or draft control mode, a position feedback signal from a sensor (28) and draft load feedback signals from load sensors (16). The servo system (50) provides a control signal to an electrode hydraulic valve (26) controlling the cylinder (24) and periodically superimposes a squarewave disturbance signal. The response thereto is analysed by the servo system to determine a gain characteristic of the soillimplement system and a gain factor influencing the control signal is adjusted in inverse relationship so that the overall gain remains substantially constant.
Inventors
- 👤 Robert Eugene Kasten
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 10:07
CPC Classifications
A; A01; A01B; A01B63/00; A01B63/02; A01B63/10; A01B63/111; A01B63/1117; F; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
137 words
A depth control system for a vehicle (10) pulling a ground working implement (14), comprising a servo-system (50) responsive to at least one sensed operating parameter of the system comprising the implement and means (12) connecting the implement to the vehicle to provide a control signal (HCVO) to control actuating means (26, 24) which adjust the working depth of the implement, characterised in that the servo system (50) is arranged to superimpose upon the control signal (HCVO) a periodic, time-varying auxiliary signal, to determine automatically a response characteristic of the servo system (50) and actuating means (26, 24) to the auxiliary signal, the response characteristic having a certain frequency relationship to the auxiliary signah and automatically to adjust a variable gain (GAIN 3) which influences the control signal (HCVO) in response to changes in the response characteristic.
Claim 2
Dependent Claim
137 words
A depth control system for a vehicle (10) pulling a ground working implement (14), comprising a servo-system (50) responsive to at least one sensed operating parameter of the system comprising the implement and means (12) connecting the implement to the vehicle to provide a control signal (HCVO) to control actuating means (26, 24) which adjust the working depth of the implement, characterised in that the servo system (50) is arranged to superimpose upon the control signal (HCVO) a periodic, time-varying auxiliary signal, to determine automatically a response characteristic of the servo system (50) and actuating means (26, 24) to the auxiliary signal, the response characteristic having a certain frequency relationship to the auxiliary signah and automatically to adjust a variable gain (GAIN 3) which influences the control signal (HCVO) in response to changes in the response characteristic.
Claim 3
Dependent Claim
24 words
A control system according to claim 1, characterised in that the auxiliary signal is intermittantly superimposed upon the control signal for a limited duration.
Claim 4
Dependent Claim
31 words
A control system according to claim 2, characterised in that a determination of the response characteristic is periodically initiated a predetermined time after initiation of the superimposing of the auxiliary signal.
Claim 5
Dependent Claim
25 words
A control system according to claim 3, characterised in that the servo system (50) integrates values representing the response characteristic for a predetermined time period.
Claim 6
Dependent Claim
27 words
A control system according to any of claims 1 to 4, characterised in that the auxiliary signal comprises a squarewave pulse train of certain frequency and duration.
Claim 7
Dependent Claim
61 words
A control system according to any of claims 1 to 5, characterised by draft force sensing means (16) for sensing draft forces produced by implement-ground interaction and position sensing means (28) for sensing implement position, the servo system (50) generating the control signal (HCVO) as a function of the sensed position, the sensed draft force and the variable gain (GAIN 3).
Claim 8
Dependent Claim
104 words
A control system according to claim 6, characterised in that the response characteristic is determined by determining a first draft force component (FCOR) in phase with the auxiliary signal, determining a second draft force component (FQUA) having a quadrature phase relationship to the auxiliary signal, determining a first control signal component (DCOR) in phase with the auxiliary signal, determining a second control signal component (DQNA) having a quadrature phase relationship with the auxiliary signal, and deriving a ratio of a sum of squares of the first and second draft force components to a sum of squares of the first and second control signal components.
Claim 9
Dependent Claim
33 words
A control system according to any of claims 1 to 7, characterised in that the variable gain (GAIN 3) is set proportional to an inverse of a value (GNSQ) representing the response characteristic.
Claim 10
Dependent Claim
121 words
A control system according to any of claims 1 to 8, characterised by an operator-controlled device (34) for generating a position signal representing a desired position of the implement, a position sensor (28) for sensing implement position, and a draft sensor (16) for sensing draft force produced by implement-ground interaction, the servo system (50) having a position control mode wherein the implement is controlled primarily as a function of the operator-controlled device and the sensed implement position and having a draft control mode wherein the implement is controlled primarily as a function of the sensed draft force, the servo system including means for preventing implement movement until the position signal generated by the operator-controlled device corresponds to the sensed implement position.
Claim 11
Dependent Claim
115 words
A control system according to any of claims 1 to 9, characterised by an operator-controlled device (34) for generating a position signal representing a desired position of the implement; a position sensor (28) for sensing implement position; and a draft sensor (16) for sensing draft force produced by implement-ground interaction, the servo system having a position control mode wherein the implement is controlled primarily as a function of the operator-controlled device and the sensed implement position and having a draft control mode wherein the implement is controlled primarily as a function of the sensed draft force, the servo system varying the magnitude of the auxiliary signal as a function of which control mode is operating.
Claim 12
Dependent Claim
33 words
A control system according to claim 10, characterised in that the auxiliary signal magnitude superimposed during draft control mode operation is larger than the auxiliary signal magnitude superimposed during position control mode operation.
References Cited (Backward Citations)
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