Real time pull-slip curve modeling in large track-type tractors
First Claim
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1. A track-type tractor adapted to characterize soil conditions during operation, the track-type tractor comprising:
- a slope sensor that provides a slope of the track-type tractor;
a track speed sensor that provides a track speed of the track-type tractor;
a processor coupled to the slope sensor and the track speed sensor; and
a memory coupled to the processor, the memory storing a plurality of modules that when executed by the processor, cause the processor to;
access a nominal pull-slip curve stored in the memory;
store data received from the slope sensor and the track speed sensor;
collect a plurality of samples of drawbar pull over a period of time;
calculate an instantaneous pull-weight ratio as a function of drawbar pull, rolling resistance, and slope for each of the plurality of samples of drawbar pull to generate a plurality of pull-weight ratios;
calculate a coefficient of traction(COT) from the plurality of instantaneous pull-weight ratios;
divide values of the nominal pull-slip curve by the COT to produce a normalized pull-slip curve;
determine an optimum operating state defined as the highest possible value of cycle power of the track-type tractor using the calculated COT, the normalized pull-slip curve, and the slope; and
provide the optimum operating state and a current operating point to a device for use in adjusting one or more operational settings of affecting the operating state of the track-type tractor.
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Abstract
A method of estimating soil conditions of a work surface during operation of a track-type tractor measures current operating conditions and current operating state to develop adjustments to a nominal pull-slip curve. The adjusted pull-slip curve is used to calculate optimum performance in terms of an input variable such as track speed. Two factors are developed to reflect soil conditions, coefficient of traction and a shear modulus adjustment that affect different portions of the nominal pull slip curve.
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Citations
20 Claims
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1. A track-type tractor adapted to characterize soil conditions during operation, the track-type tractor comprising:
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a slope sensor that provides a slope of the track-type tractor; a track speed sensor that provides a track speed of the track-type tractor; a processor coupled to the slope sensor and the track speed sensor; and a memory coupled to the processor, the memory storing a plurality of modules that when executed by the processor, cause the processor to; access a nominal pull-slip curve stored in the memory; store data received from the slope sensor and the track speed sensor; collect a plurality of samples of drawbar pull over a period of time; calculate an instantaneous pull-weight ratio as a function of drawbar pull, rolling resistance, and slope for each of the plurality of samples of drawbar pull to generate a plurality of pull-weight ratios; calculate a coefficient of traction(COT) from the plurality of instantaneous pull-weight ratios; divide values of the nominal pull-slip curve by the COT to produce a normalized pull-slip curve; determine an optimum operating state defined as the highest possible value of cycle power of the track-type tractor using the calculated COT, the normalized pull-slip curve, and the slope; and provide the optimum operating state and a current operating point to a device for use in adjusting one or more operational settings of affecting the operating state of the track-type tractor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of characterizing soil conditions during operation of a track-type tractor, the method comprising:
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providing a nominal pull-slip curve corresponding to a standard soil condition; receiving, at a processor, data from at least one sensor of the track-type tractor, the data corresponding to a slope of the track-type tractor and one or more of a track speed, a ground speed, and a drawbar pull; producing, at the processor, a coefficient of traction (COT), wherein producing the COT includes; calculating a plurality of instantaneous pull-weight ratio values using the drawbar pull and the slope; removing instantaneous pull-weight ratio values from the plurality of instantaneous pull-weight ratio values that fail to meet a first screening criteria; and averaging the instantaneous pull-weight ratio values that meet the first screening criteria to produce the COT; normalizing, at the processor, the nominal pull-slip curve by the COT to produce a normalized pull-slip curve; producing, at the processor, a shear modulus adjustment factor that characterizes soil conditions, wherein producing the shear modulus adjustment factor includes; calculating a plurality of normalized pull-weight ratio values; removing normalized pull-weight ratio values that fail to meet a second screening criteria; calculating the shear modulus adjustment factor from the normalized pull-weight ratio values meeting the second screening criteria; applying the shear modulus adjustment factor to the normalized pull-slip curve to obtain an adjusted pull-slip curve; and using the adjusted pull-slip curve, the COT, and the slope to determine an optimum performance; and providing the optimum performance to a device for use in adjusting a current operating state of the track-type tractor to reach the optimum performance. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of characterizing soil conditions during operation of a track-type tractor implemented by execution of computer-executable instructions stored on a computer readable memory storing computer-executable instructions, the method comprising:
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providing a nominal pull-slip curve corresponding to a standard soil condition; receiving, at a processor, data from at least one sensor of the track-type tractor, the data corresponding to a slope of the track-type tractor and one or more of a track velocity, a ground speed, and a drawbar pull; producing, at the processor, a coefficient of traction (COT), wherein producing the COT includes; calculating a plurality of instantaneous pull-weight ratios using the drawbar pull and the slope; removing from the plurality of instantaneous pull-weight ratios the instantaneous pull-weight ratios that fail to meet a first screening criteria, the first screening criteria including removing the instantaneous pull-weight ratios corresponding to a slip value less than 20%; and averaging the instantaneous pull-weight ratios that meet the first screening criteria to produce the COT; normalizing, at the processor, the nominal pull-slip curve by the COT to produce a normalized pull-slip curve; producing, at the processor, a shear modulus adjustment factor, wherein producing the shear modulus adjustment factor includes; calculating a plurality of normalized pull-weight ratio values; removing normalized pull-weight ratio values that fail to meet a second screening criteria, the second screening criteria including removing the normalized pull-weight ratio values corresponding to a slip outside a range of about 0.5% to about 40%; calculating the shear modulus adjustment factor from the normalized pull-weight ratio values meeting the second screening criteria; applying the shear modulus adjustment factor to the normalized pull-slip curve to obtain an adjusted pull-slip curve; and using the adjusted pull-slip curve, the COT, and the slope to determine an optimum performance; and providing the optimum performance to a device for use in adjusting an operating state of the track-type tractor to achieve a performance closer to the optimum performance. - View Dependent Claims (19, 20)
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Specification