# US 2014/0156152 A1 · Determining an Optimum Operating Point of an Earth Moving Machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156152 A1 - Document ID: US20140156152A1 - Status: Published application - Kind: A1 - Application number: 13/690,757 - Filed: 2012-11-30 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Caterpillar Inc. - Applicants: Caterpillar Inc. - Inventors: Joseph Faivre; Nathaniel Doy - Web page: https://patentgrep.com/patent/US20140156152A1 ## CPC - B60K 6/12: by means of a chargeable fluidic accumulator - G05D 1/00: Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots (drive control systems specially adapted for autonomous road vehicles B60W60/00) - B60K 6/46: Series type - B60W 20/10: Controlling the power contribution of each of the prime movers to meet required power demand - B62D 49/00: Tractors (of walk type B62D51/04; endless- track features B62D55/00 {; transport specially adapted for underground galleries E21F13/02}) - E02F 9/20: Drives; Control devices (gearings in general F16H; controlling in general G05; electric multi-motor drives H02K, H02P) - E02F 9/2075: {of the hybrid type (for vehicles in general B60W20/00)} - E02F 9/2246: {Control of prime movers, e.g. depending on the hydraulic load of work tools} - E02F 9/2253: {Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission} - E02F 9/26: Indicating devices {(E02F5/145 takes precedence)} - B60W 2050/146: {Display means} - B60W 2300/17: Construction vehicles, e.g. graders, excavators - B60W 2520/26: Wheel slip - B60W 2540/10: Accelerator pedal position - B60W 2540/12: Brake pedal position - B60W 2540/16: Ratio selector position - Y02T 10/62: Hybrid vehicles - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Optimum performance in an earth moving machine, such as a track-type tractor, is a function of many complex factors such as power delivered to the tracks, load, soil type, soil conditions, speed, terrain, etc. To determine an operating point associated with optimum performance, operational data may be collected, processed, and applied to known performance curves for well characterized conditions to develop recommended operating conditions. A coefficient of traction and a shear modulus adjustment, reflecting surface conditions, are calculated at the tractor during operation and used to offset a table of ideal condition operating points for use in soil characterizations. Using this and other inputs, a cycle power equation gives a curve that peaks at a theoretical optimum performance. However, the number of variables make an analytic solution impossible. An iterative approach determines a range of operating conditions associated with optimum performance. ## Claims ### Claim 1 A method of determining an optimum performance in a track-type tractor, the method comprising: receiving, at a processor of the track-type tractor, inputs from the track-type tractor related to current operating conditions and a current operating state; calculating a current performance based on the current operating conditions and the current operating state; generating an estimated operating environment using the current operating conditions and the current operating state; iteratively solving, via a processor of the track-type tractor, a performance equation that incorporates the estimated operating environment over a range of values of an input variable to determine a peak value of the performance equation and an input state required to achieve the peak value, wherein the peak value corresponds to the optimum performance of the track-type tractor; normalizing the current performance to the optimum performance to produce a normalized performance; and providing the normalized performance, the optimum performance, and the input state required to achieve the optimum performance to a device for use in adjusting the current operating state to improve or maintain a performance of the track-type tractor. ### Claim 2 (depends on 1) The method of claim 1, wherein the input variable is a track speed. ### Claim 3 (depends on 2) The method of claim 2, further comprising: generating the performance equation in terms of track speed using a cycle power performance equation: CyclePower = ( D   B   P - RollRes - mg   sin   θ Pitch )  v GndSpd  1 1 + v gndspd v rev  d cycle d carry + ( T Load + T spread )  v gndspd d carry and generating the cycle power performance equation in terms of track speed by substituting terms v gndspd = v trkspd  ( 1 - slip / 100 ) slip estimate = f SlipPull - 1  ( r PW )  k adj r PW = D   B   P - RollRes C   O   T · mg   cos   θ Pitch D   B   P = f DBPcurve - 1  ( v trk ) ### Claim 4 (depends on 3) The method of claim 3, wherein iteratively solving the cycle power performance equation comprises: setting a value of the input variable to an initial value; solving the cycle power performance equation to develop a result; incrementing the value of the input variable by an iteration step size, solving the cycle power performance equation and comparing a current result and a previous result; i) identifying that a peak output value has passed; ii) setting the value of the input variable to a previous value; iii) incrementing the value of the input variable by a new iteration step size smaller than a previous step size, solving the cycle power performance equation and comparing current and previous results; repeating i, ii, and iii to determine the peak output value of the cycle power performance equation at a current iteration step size below a threshold iteration step size; storing the peak output value at a computer memory of the track-type tractor as the optimum performance of the track-type tractor; and storing at the computer memory of the track-type tractor the value of the input variable corresponding to the peak output value as an optimum operating state of the track-type tractor. ### Claim 5 (depends on 4) The method of claim 4, wherein the value of the input variable at which the peak value of the performance equation occurs is the optimum operating state, the method further comprising providing the optimum operating state to the device associated with adjusting the current operating state of the track-type tractor. ### Claim 6 (depends on 1) The method of claim 1, wherein the device is an operator display showing a unitless representation of the normalized performance relative to the optimum performance. ### Claim 7 A system for determining an optimum performance in a track-type tractor comprising: a track speed sensor that provides track speed of the track-type tractor; a slope sensor that provides a slope of the track-type tractor; a processor coupled to each of the track speed sensor and the slope sensor, a torque sensor coupled to the processor that provides information used by the processor to develop a drawbar pull value; a memory coupled to the processor that stores executable code that cause the processor to use a ground speed, the track speed, the slope, and the drawbar pull value to develop the optimum performance in terms of an input corresponding to a current operating state, and to generate a current value of performance; and a device that receives the optimum performance and the current value of performance for use in adjusting an operating state of the track-type tractor to improve performance. ### Claim 8 (depends on 7) The system of claim 7, wherein the memory further stores a cycle power performance equation in terms of the input corresponding to the current operation state for use in evaluating optimum performance in terms of the input. ### Claim 9 (depends on 8) The system of claim 8, wherein the input corresponding to current operating state is track speed. ### Claim 10 (depends on 8) The system of claim 8, wherein the memory further stores code that cause the processor to iteratively solve the cycle power performance equation for a range of track speeds to determine the optimum performance. ### Claim 11 (depends on 10) The system of claim 10, wherein the code that cause the processor to iteratively solve the cycle power performance equation to determine the optimum performance comprises code that cause the processor to: set a value of an input variable to an initial value; solve the cycle power performance equation to develop a result; increment the value of the input variable by a step size, solving the cycle power performance equation and comparing current and previous results; i) identify that a peak output value has passed; ii) set the value of the input variable to a previous value; iii) increment the value of the input variable by a new iteration step size smaller than a previous step size, solving the cycle power performance equation and comparing current and previous results; repeat i, ii, and iii to determine the peak output value of the cycle power performance equation at a current step size below a threshold iteration step size; store the peak output value as the optimum performance of the track-type tractor; and store the value of the input variable corresponding to the peak output value as an optimum operating state of the track-type tractor. ### Claim 12 (depends on 9) The system of claim 9, wherein the memory further stores code that cause the processor to: model operating conditions to develop a shear modulus factor; generate an adjusted nominal pull-slip curve with the shear modulus factor; and estimate slip as an inverse function of the adjusted nominal pull-slip curve as a function of drawbar pull in order calculate the ground speed from slip and the track speed. ### Claim 13 (depends on 8) The system of claim 8, further comprising a ground speed sensor that provides the ground speed of the track-type tractor. ### Claim 14 (depends on 13) The system of claim 13, wherein the memory further stores a cycle power performance equation: CyclePower = ( D   B   P - RollRes - mg   sin   θ Pitch )  v GndSpd  1 1 + v gndspd v rev  d cycle d carry + ( T Load + T spread )  v gndspd d carry . ### Claim 15 (depends on 14) The system of claim 14, wherein the memory further stores code that cause the processor to iteratively solve the cycle power performance equation for a range of track speeds to determine the optimum performance. ### Claim 16 A method of determining optimum performance in a track-type tractor, the method comprising: receiving inputs from the track-type tractor related to a current operating condition and a current operating state; calculating a current performance based on the current operating condition and the current operating state; iteratively solving a cycle power performance equation: CyclePower = ( f DBPcurve - 1  ( v trk ) - RollRes - mg   sin   θ Pitch )  v trk  ( 1 - slip / 100 ) 1 + v trk  ( 1 - slip / 100 ) v rev  d cycle d carry + ( T Load + T spread )  v trk  ( 1 - slip / 100 ) d carry over a range of values of track speed to determine a peak value of the cycle power performance equation, wherein the peak value corresponds to an optimum performance of the track-type tractor; normalizing the current performance to the optimum performance to produce a normalized performance; providing the normalized performance and the optimum performance to a device associated with adjusting the current operating state to improve or maintain a performance of the track-type tractor; and adjusting the current operating state of the track-type tractor via the device. ### Claim 17 (depends on 16) The method of claim 16, wherein receiving inputs from the track-type tractor comprises receiving a slope of the track-type tractor, a track speed, and data used to calculate drawbar pull. ### Claim 18 (depends on 17) The method of claim 17, wherein receiving inputs from the track-type tractor further comprises receiving a ground speed of the track-type tractor. ### Claim 19 (depends on 16) The method of claim 16, wherein iteratively solving the cycle power performance equation comprises: setting a value of an input variable to an initial value; solving the cycle power performance equation to develop a result; incrementing the value of the input variable by an iteration step size, solving the cycle power performance equation and comparing current and previous results; i) identifying that a peak output value has passed; ii) setting the value of the input variable to a previous value; iii) incrementing the value of the input variable by a new iteration step size smaller than a previous step size, solving the cycle power performance equation and comparing current and previous results; repeating i, ii, and iii to determine the peak output value of the cycle power performance equation at a current iteration step size below a threshold iteration step size; storing the peak output value as the optimum performance of the track-type tractor; and storing the value of the input variable corresponding to the peak output value as an optimum operating state of the track-type tractor.