Sonic ranging grade level controller
First Claim
Patent Images
1. A method of controlling the position of an implement in relationship to a surface, comprising the steps of:
- (a) selecting a desired relationship between the implement and the surface;
(b) emitting a sonic wave;
(c) detecting echoes produced by the reflection of the sonic wave from the surface; and
(d) generating a correction signal which causes the implement to alter its relationship to the surface if a difference between a desired distance and a measured distance exceeds a certain amount, wherein a transfer function defining a relationship between the difference and the correction signal magnitude is linear.
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Abstract
An implement position control device including a central processing unit (6) coupled to an ultrasonic transducer (17) and receiver/amplifier (20) adapted to calculate the distance to a reference target (12 and a relatively more distant surface (9). Control pulses are initiated by the CPU (6) to manipulate a solenoid (25) by means of a valve driver (24) in response to the calculated distance measurements. An autotune task (26) causes a series of precise pulses to manipulate the solenoid, thereby permitting calculation of the transfer function (52) defining the relationship between pulse width and implement position.
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Citations
19 Claims
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1. A method of controlling the position of an implement in relationship to a surface, comprising the steps of:
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(a) selecting a desired relationship between the implement and the surface; (b) emitting a sonic wave; (c) detecting echoes produced by the reflection of the sonic wave from the surface; and (d) generating a correction signal which causes the implement to alter its relationship to the surface if a difference between a desired distance and a measured distance exceeds a certain amount, wherein a transfer function defining a relationship between the difference and the correction signal magnitude is linear. - View Dependent Claims (2, 4)
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3. A method of controlling the position of an implement in relation to a surface comprising the steps of:
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(a) selecting a desired relationship between the implement and the surface; (b) emitting a sonic wave; (c) detecting echoes produced by the reflection of the sonic wave from the surface; (d) detecting the echoes of the sonic wave from a reference target; (e) monitoring the rate of change of echo delays received from the reference target; (f) monitoring the rate of echo delays received from the surface; (g) comparing the rate of change of between the reference target echo delays and the surface echo delays; (h) recalculating the speed of sound based on reference target echo data only if the reference target echo data changed at a rate that was less than or equal to changes in the measured surface echo delay; (i) calculating a compensation factor based on any discrepancy between the calculated distance and the actual distance to the reference target; (j) applying the compensation factor to the calculated distance to the surface, thereby generating a corrected measurement of the distance between the implement and the surface; (k) generating a signal which causes the implement to alter its relationship to the surface if the difference between the desired distance and the measured distance exceeds a certain amount; and (l) generating a signal causing a solenoid operatively connected to the instrument to be continuously oscillated if the difference between the desired distance and the measured distance is less than a predetermined value.
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5. A method of controlling the position of an implement in relation to a surface, comprising the steps of:
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(a) selecting a desired relationship between the implement and the surface; (b) emitting a sonic wave; (c) detecting echoes produced by the reflection of the sonic wave from the surface; (d) detecting the echoes of the sonic wave from a reference target; (e) calculating a distance to the reference target; (f) comparing the calculated distance to the reference target to the known distance to the reference target; (g) calculating a compensation factor based on any discrepancy between the calculated distance and the actual distance to the reference target; (h) applying the compensation factor to the calculated distance to the surface, thereby generating a corrected measurement of the distance between the implement and the surface; (i) generating a correction pulse which causes the implement to alter its relationship to the surface if the difference between the desired distance and the measured distance exceeds a certain amount, wherein a transfer function defining a relationship between the error and the pulse magnitude is linear; and (j) generating a signal causing a solenoid operatively connected to the instrument to be continuously oscillated if the difference between the desired distance and the measured distance is less than a predetermined value.
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6. A method of determining the response characteristic of an implement control system for positioning an implement with respect to a surface, comprising the steps of:
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(a) measuring a distance to the surface; (b) manipulating the implement with respect to the surface; (c) measuring any resulting variation in distance between the implement and the surface; and (d) calculating the relationship between the manipulation and the resulting variation of the implement relative to the surface, thereby determining the response characteristic of the implement control system. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification