US5684691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling draft of an agricultural implement
Assignee: CNH Industrial America LLC
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Filing: 1995-04-17
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Granted: 1997-11-04
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Expires: 2015-04-17
Abstract
Abstract A control system for regulating the elevational position of an implement carried or trailed by a vehicle, such as a tractor, includes draft force sensors for detecting the draft force produced by interaction of the implement with the ground, and a command device for setting a reference level of draft force. A control circuit coupled to the sensors and to the command device generates a draft force error signal representing the deviation of the sensed draft force from the desired level, and a draft force derivative signal representing the rate of change of the sensed draft force. The control circuit generates control signals for raising and lowering the implement following a predetermined control routine in response at least to the draft error signals. The rate of movement of the implement in response to the control signals is limited in response to the draft force error signal and the draft derivative signal. The limit on the rate of movement of the implement is preferably determined through fuzzy logic wherein the draft error signals and draft derivative signals are classified into sets and the rate limit is derived from the degree of membership of the signals in the sets. The control system also preferably generates a weight signal representative of the weight of the implement and membership functions defining the sets are selected based on categorization of the implement weight.
Inventors
- 👤 Abraham Orbach
- 👤 William J. Schubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:42
CPC Classifications
A; A01; A01B; A01B63/00; A01B63/02; A01B63/10; A01B63/111; A01B63/112
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
210 words
An apparatus for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an implement positioning system including an actuator for selectively raising and lowering the implement in response to control signals, the apparatus comprising: a draft sensor for detecting draft force on the implement caused by interaction of the implement with the ground and for generating draft force signals representative thereof; a draft force command device configured to generate draft force reference signals; a control circuit coupled to the draft sensor, to the draft force command device and to the actuator, the control circuit determining draft force error values based upon the difference between the draft force signals and the draft force reference signals and generating control signals for causing movement of the actuator based at least upon the draft force error values, the control circuit generating the control signals in the form of pulse-width-modulated signals having predetermined duty cycles, the rate of movement of the actuator being proportional to the duty cycle of the control signals; and a response signal generating circuit coupled to the control circuit to automatically limit a response rate of the actuator in response to the control signals by limiting the duty cycle of the control signals.
Claim 2
Independent Claim
210 words
An apparatus for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an implement positioning system including an actuator for selectively raising and lowering the implement in response to control signals, the apparatus comprising: a draft sensor for detecting draft force on the implement caused by interaction of the implement with the ground and for generating draft force signals representative thereof; a draft force command device configured to generate draft force reference signals; a control circuit coupled to the draft sensor, to the draft force command device and to the actuator, the control circuit determining draft force error values based upon the difference between the draft force signals and the draft force reference signals and generating control signals for causing movement of the actuator based at least upon the draft force error values, the control circuit generating the control signals in the form of pulse-width-modulated signals having predetermined duty cycles, the rate of movement of the actuator being proportional to the duty cycle of the control signals; and a response signal generating circuit coupled to the control circuit to automatically limit a response rate of the actuator in response to the control signals by limiting the duty cycle of the control signals.
Claim 3
Dependent Claim
26 words
The control system of claim 1, wherein the response signal generating circuit limits the response rate of the actuator based upon the draft force error values.
Claim 4
Dependent Claim
22 words
The control system of claim 1, wherein the control circuit and the response signal generating circuit are included in a programmed microprocessor.
Claim 5
Dependent Claim
25 words
The control system of claim 1, further comprising at least one sensing device for generating a weight signal representative of the weight of the implement.
Claim 6
Independent Claim
156 words
A method for controlling the rate of elevational movement of an implement carried or trailed by a vehicle and capable of being raised and lowered in response to control signals, the method comprising the steps of: sensing a draft force resulting from interaction between the implement and the ground; setting a desired level of draft force; generating a draft error value representative of the difference between the sensed draft force and the desired draft force; generating control signals to selectively raise and lower the implement based at least on the draft error value, the control signals being pulse-width-modulated signals having a duty cycle proportional to the rate of movement of the implement; generating a movement rate limiting signal based at least on the draft error value; and limiting the rate of movement of the implement by limiting the duty cycle of the control signals in response to the control signals based on the rate limiting signal.
Claim 7
Independent Claim
156 words
A method for controlling the rate of elevational movement of an implement carried or trailed by a vehicle and capable of being raised and lowered in response to control signals, the method comprising the steps of: sensing a draft force resulting from interaction between the implement and the ground; setting a desired level of draft force; generating a draft error value representative of the difference between the sensed draft force and the desired draft force; generating control signals to selectively raise and lower the implement based at least on the draft error value, the control signals being pulse-width-modulated signals having a duty cycle proportional to the rate of movement of the implement; generating a movement rate limiting signal based at least on the draft error value; and limiting the rate of movement of the implement by limiting the duty cycle of the control signals in response to the control signals based on the rate limiting signal.
Claim 8
Dependent Claim
63 words
The method of claim 5, wherein the limit on the rate of movement of the implement is determined by classifying the draft error value in at least two sets in accordance with predetermined membership functions and generating a response signal representative of the limit on the rate of movement based upon the degree of membership of the draft error value in the sets.
Claim 9
Dependent Claim
37 words
The method of claim 6, comprising the further steps of generating a weight signal representative of the weight of the implement carried or trailed by the vehicle and selecting predetermined membership functions based upon the weight signal.
Claim 10
Dependent Claim
54 words
The method of claim 5, including the further step of generating a draft derivative value representative of the rate of change of the sensed draft force and wherein the rate of movement of the implement in response to the control signals is limited based on the draft error value and the draft derivative value.
Claim 11
Dependent Claim
74 words
The method of claim 8, wherein the limit on the rate of movement of the implement is determined by classifying the draft error value and the draft derivative value in at least two respective sets in accordance with predetermined membership functions and generating a response signal representative of the limit on the rate of movement based upon the degree of membership of the draft error value and the draft derivative value in the sets.
Claim 12
Dependent Claim
47 words
The method of claim 9, comprising the further steps of generating a weight signal representative of the weight of the implement carried or trailed by the vehicle and selecting predetermined membership functions for the draft error value and the draft derivative value based upon the weight signal.
Claim 13
Independent Claim
99 words
A method for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an actuator for selectively raising and lowering the implement in response to control signals, the method comprising the steps of: sensing a parameter proportional to the weight of the implement and generating a weight signal representative thereof; categorizing the implement into one of at least two weight categories; generating control signals for moving the actuator to selectively raise and lower the implement; and limiting the rate of movement of the implement based upon the weight category of the implement.
Claim 14
Independent Claim
99 words
A method for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an actuator for selectively raising and lowering the implement in response to control signals, the method comprising the steps of: sensing a parameter proportional to the weight of the implement and generating a weight signal representative thereof; categorizing the implement into one of at least two weight categories; generating control signals for moving the actuator to selectively raise and lower the implement; and limiting the rate of movement of the implement based upon the weight category of the implement.
Claim 15
Dependent Claim
130 words
The method of claim 11, comprising the further steps of: detecting draft force resulting from interaction of the implement with the ground and generating a sensed draft force signal representative thereof; generating a reference draft force signal representative of a desired level of draft force; generating a draft force error signal representing the difference between the sensed draft force signal and the reference draft force signal; and selecting draft force error membership functions based upon the weight of the implement, the draft force error membership functions classifying the draft force error signal in at least two draft error sets by degree; wherein the rate of movement of the implement is limited based at least upon the degree of membership of the draft force error signal in the draft error sets.
Claim 16
Dependent Claim
100 words
The method of claim 12, comprising the further steps of: generating a draft derivative signal representing the rate of change of the sensed draft force; selecting draft derivative membership functions based upon the weight of the implement, the draft derivative membership functions classifying the draft derivative signal in at least two draft derivative sets by degree; wherein the rate of movement of the implement is limited based upon the degree of membership of the draft force error signal in the draft force error sets and the degree of membership of the draft force derivative in the draft force derivative sets.
Claim 17
Independent Claim
184 words
An apparatus for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an implement positioning system including an actuator for selectively raising and lowering the implement in response to control signals, the apparatus comprising: a draft sensor for detecting draft force on the implement caused by interaction of the implement with the ground and for generating draft force signals representative thereof; a draft force command device configured to generate draft force reference signals; a control circuit coupled to the draft sensor, to the draft force command device and to the actuator, the control circuit determining draft force error values based upon the difference between the draft force signals and the draft force reference signals and generating control signals for causing movement of the actuator based at least upon the draft force error values; and a response signal generating circuit coupled to the control circuit to automatically limit a response rate of the actuator in response to the control signals based upon the draft force error values and the rate of change in the sensed draft force.
Claim 18
Independent Claim
184 words
An apparatus for controlling the elevation of an implement carried or trailed by a vehicle, the implement being coupled to an implement positioning system including an actuator for selectively raising and lowering the implement in response to control signals, the apparatus comprising: a draft sensor for detecting draft force on the implement caused by interaction of the implement with the ground and for generating draft force signals representative thereof; a draft force command device configured to generate draft force reference signals; a control circuit coupled to the draft sensor, to the draft force command device and to the actuator, the control circuit determining draft force error values based upon the difference between the draft force signals and the draft force reference signals and generating control signals for causing movement of the actuator based at least upon the draft force error values; and a response signal generating circuit coupled to the control circuit to automatically limit a response rate of the actuator in response to the control signals based upon the draft force error values and the rate of change in the sensed draft force.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-03 | 2001-05-05 | 2001-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-03 | 2005-05-05 | 2005-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-03 | 2009-05-05 | 2009-11-04 | $7700.00 | Window Closed / Lapsed |