# US 11,078,937 B2 · Performance enhancement of controllers for varying temperature conditions in hydraulic actuators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,937 B2 - Document ID: US11078937B2 - Status: Granted - Kind: B2 - Application number: 16/716,590 - Filed: 2019-12-17 - Published: 2021-04-22 - Granted: 2021-08-03 - Earliest claimed: 2019-10-17 - Assignees: Hamilton Sunstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Ashish Vijay; Harish Venkatesha; Anil Prasad Josyula - Web page: https://patentgrep.com/patent/US11078937B2 ## CPC - F15B 21/045: Compensating for variations in viscosity or temperature - F15B 21/087: {Control strategy, e.g. with block diagram} - F15B 15/2884: {using sound, e.g. ultrasound} - G01K 11/24: of the velocity of propagation of sound - F15B 2211/6336: representing a state of the output member, e.g. position, speed or acceleration - F15B 2211/66: Temperature control methods - F15B 2215/00: Fluid-actuated devices for displacing a member from one position to another - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) ## Abstract Provided are embodiments for a system including an adaptive controller, wherein the system includes a hydraulic actuator including a fluid medium, and a sensor that is disposed on the hydraulic actuator, wherein the sensor is configured to obtain sensor data of the actuator. The system also includes a processor configured to calculate an ultrasonic velocity in the fluid medium using the sensor data, wherein the processor is further configured to determine a temperature of the fluid medium based at least in part on the calculated velocity, and a controller coupled to the actuator, wherein the controller is configured to control the actuator based at least in part on the calculated velocity and determined temperature. Also provided are embodiments for a method for operating the adaptive controller. ## Claims ### Claim 1 A system including an adaptive controller, the system comprising: a hydraulic actuator comprising a fluid medium; a sensor that is disposed on the hydraulic actuator, wherein the sensor is configured to obtain sensor data of the actuator; and a processor configured to calculate an ultrasonic velocity in the fluid medium using the sensor data, wherein the processor is further configured to determine a temperature of the fluid medium based at least in part on the calculated velocity; and a controller coupled to the actuator, wherein the controller is configured to control the actuator based at least in part on the calculated velocity and determined temperature, wherein the controller further comprises a speed-temperature lookup table (LUT) and a temperature-PI controller LUT to determine the command signal. ### Claim 2 (depends on 1) The system of claim 1, wherein the sensor is an ultrasonic position sensor. ### Claim 3 (depends on 1) The system of claim 1, wherein the actuator comprises a stepped target which is used to measure a duration of a pulse to traverse the fluid medium to and from the target. ### Claim 4 (depends on 3) The system of claim 3, wherein the sensor data comprises a first duration for a first pulse to traverse the fluid medium to the stepped target and a second duration for a second pulse to traverse the fluid medium to the stepped target. ### Claim 5 (depends on 4) The system of claim 4, wherein the first duration is measured from a first location of the stepped target and the second duration is measured from a second location of the stepped target, wherein the first location is at a different distance from the sensor as the second location. ### Claim 6 (depends on 1) The system of claim 1, wherein the calculation for the ultrasonic velocity is calculated according to the following equation: Speed ⁢ ⁢ ( @ k ) = T ⁢ ⁢ 2 ⁢ ( @ k ) - T ⁢ ⁢ 1 ⁢ ( @ k ) h wherein T1 is a first duration for a pulse signal to traverse the fluid medium; T2 is a second duration for a pulse signal to traverse the fluid medium, k is the current temperature of the fluid medium; and h is a height of the stepped target of the actuator. ### Claim 7 (depends on 1) The system of claim 1, further comprising a dual-sensor arrangement configured to obtain first sensor data and second sensor data. ### Claim 8 A method for controlling a hydraulic actuator, the method comprising: obtaining sensor data of an actuator; calculating an ultrasonic velocity in a fluid medium of the actuator based at least in part on the sensor data; determining a temperature of the fluid medium based at least in part on the calculated velocity; referencing a speed-temperature lookup table (LUT) and a temperature-PI controller LUT to determine a command signal to control the actuator; and controlling the actuator based at least in part on the calculated velocity and determined temperature. ### Claim 9 (depends on 8) The method of claim 8, wherein the sensor data is obtained using an ultrasonic position sensor. ### Claim 10 (depends on 8) The method of claim 8, wherein the actuator comprises a stepped target which is used to measure a duration of a pulse to traverse the fluid medium to and from the target. ### Claim 11 (depends on 10) The method of claim 10, wherein the sensor data is obtained by sending a first pulse across the fluid medium to the stepped target to determine a first duration and sending a second pulse across the fluid medium to the stepped target to determine a second pulse. ### Claim 12 (depends on 11) The method of claim 11, wherein the first duration is measured from a first location of the stepped target and the second duration is measured from a second location of the stepped target, wherein the first location is at a different distance from the sensor as the second location. ### Claim 13 (depends on 8) The method of claim 8, wherein the calculation for the ultrasonic velocity is calculated according to the following equation: Speed ⁢ ⁢ ( @ k ) = T ⁢ ⁢ 2 ⁢ ( @ k ) - T ⁢ ⁢ 1 ⁢ ( @ k ) h wherein T1 is a first duration for a pulse signal to traverse the fluid medium; T2 is a second duration for a pulse signal to traverse the fluid medium, k is the current temperature of the fluid medium; and h is a height of the stepped target of the actuator. ### Claim 14 (depends on 8) The method of claim 8, further comprising using a first sensor and a second sensor in a dual-sensor arrangement to obtain first sensor data and second sensor data.