# US 2010/0168940 A1 · Position control system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0168940 A1 - Document ID: US20100168940A1 - Status: Published application - Kind: A1 - Application number: 12/344,633 - Filed: 2008-12-29 - Published: 2010-07-01 - Earliest claimed: 2008-12-29 - Assignees: Universal City Studios LLC - Inventors: Steven Morris KING - Web page: https://patentgrep.com/patent/US20100168940A1 ## CPC - B61L 25/021: {Measuring and recording of train speed} - A63G 7/00: Up-and-down hill tracks; Switchbacks - B60L 3/10: Indicating wheel slip {; Correction of wheel slip} - B61C 15/12: by reducing the driving power - B60L 2200/26: Rail vehicles - Y02T 10/72: Electric energy management in electromobility - Y02T 90/16: Information or communication technologies improving the operation of electric vehicles - B61L: GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC (brakes or auxiliary equipment B61H, B61K; point or crossing construction E01B) - A63G: MERRY-GO-ROUNDS; SWINGS; ROCKING-HORSES; CHUTES; SWITCHBACKS; SIMILAR DEVICES FOR PUBLIC AMUSEMENT - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - B61C: LOCOMOTIVES; MOTOR RAILCARS (vehicles in general B60; frames or bogies B61F; special railroad equipment for locomotives B61J, B61K) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method for determining slippage of at least one wheel of at least one vehicle having a motor and a processor that communicates velocity commands to the motor for varying a velocity of the vehicle is presented. The method includes determining an actual velocity of the vehicle over regular intervals; comparing, over regular intervals, the actual velocity of the vehicle to the expected velocity from the magnitude of the velocity commands to determine whether there is slip of the wheel of the vehicle; and reducing the magnitude of the velocity commands to equal approximately the actual velocity of the vehicle where there is slip of the wheel. A system and circuit carrying out the method are also presented. ## Claims ### Claim 1 A method for controlling a plurality of vehicles each having wheels located on a fixed path, the method comprising: mounting a processor on each vehicle; mounting a vehicle sensor device to each vehicle; using each processor and each vehicle sensor device to determine an actual velocity of each vehicle while each vehicle is moving along the path; and using a position control correction module to compare each vehicle's actual velocity to each vehicle's velocity commands to determine if wheel slip is occurring and to decrease the magnitude of vehicle velocity commands where wheel slip occurs. ### Claim 2 (depends on 1) The method of claim 1, wherein the position control correction module is further configured to ramp up the magnitude of vehicle velocity commands after wheel slip is eliminated along the fixed path. ### Claim 3 (depends on 1) The method of claim 1, wherein the position control correction module is further applied to compensate for changes in vehicle velocity because of wheel deterioration. ### Claim 4 (depends on 1) The method of claim 1, wherein the position correction module comprises a cosine algorithm. ### Claim 5 (depends on 4) The method of claim 4, wherein the cosine algorithm corrects velocity error accumulation. ### Claim 6 (depends on 1) The method of claim 1, wherein each vehicle comprises an entertainment vehicle and the path comprises a track having a pair of rails. ### Claim 7 A ride control system for controlling a plurality of vehicles on a path, the ride control system comprising: a path processor; and a vehicle processor supported by each vehicle; a vehicle driving and stopping system in circuit with each vehicle processor; and a vehicle sensor device in circuit with each vehicle processor; wherein each vehicle processor is configured to communicate with the path processor and to use the vehicle sensor device to identify an actual velocity of a particular vehicle and further to use a position control correction module and a vehicle driving and stopping system to correct for variation in spacing between vehicles. ### Claim 8 (depends on 7) The system of claim 7, wherein the position control correction module is configured to compensate for changes in vehicle spacing caused by wheel slip along the fixed path. ### Claim 9 (depends on 8) The system of claim 8, wherein the position control correction module is further applied to compensate for changes in vehicle velocity caused bywheel deterioration. ### Claim 10 (depends on 7) The system of claim 7, wherein the position control correction module comprises a cosine algorithm. ### Claim 11 A method for determining slippage of at least one wheel of at least one vehicle having a motor and a processor that communicates velocity commands to the motor for varying a velocity of the vehicle, the method comprising: determining an actual velocity of the vehicle; comparing the actual velocity of the vehicle to the expected velocity from the magnitude of the velocity commands to determine whether there is slip of the wheel of the vehicle; and reducing the magnitude of the velocity commands to equal approximately the actual velocity of the vehicle where there is slip of the wheel. ### Claim 12 (depends on 11) The method of claim 11 further comprising ramping up the magnitude of the velocity commands once no wheel slip occurs. ### Claim 13 (depends on 11) The method of claim 11 wherein the at least one vehicle comprises a plurality of vehicles located on a fixed path.