ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Electrohydraulic powered Actuator

1. ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Electrohydraulic powered Actuators Prepared by: Oscar Delgado Dept. of Electrical and Computer Engineering Utah State University E: oscar.delgado_vargas@aggiemail.usu.edu F: (435)797-3054 (ECE Dept.) 3/7/2009

2. Outline • Reference list • To probe further • Major applications • Basic working principle illustrated • A typical sample configuration in application • Major specifications • Limitations • Purchasing Information ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Reference list • Robert Bishop, Mechatronics Handbook, CRC press. http://www.engnetbase.com//books/774/0066ch20.pdf • Hindwarsh John, Renfrew Alasdair. Electrical machines and Drive Systems. Third Edition. 2000. • www.wikipedia.com • machinedesign.com/article/electrohydraulic-actuators • http://www.woodward.com/turbine/steam/steam2/actuators.cfm ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. To explore further • http://www.freshpatents.com/-dt20090212ptan20090041599.php • Flowcontrol.globalspec.com/LearnMore/Flow_Transfer_Control/...Actuators.../Hydraulic_Electrohydraulic_Valve_Actuators. • findarticles.com/p/articles/mi_m0FZX/is_3_74/ai_n24963512 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

5. Major applications • The application of electronic controls to fluid power systems resulted in electrohydraulic control systems. Electrohydraulics has been widely used in aerospace, industrial, and mobile fluid power systems. • Electrohydraulic controls have some advantages over other types of control. First, an electrohydraulic system can be operated over a wide range of speeds, and its speed can be controlled continuously. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

6. Major applications • More important, an electrohydraulic system can be stalled or operated under very large acceleration without causing its components to be damaged. One example of an application is on steam turbines where isochronous control, load sharing, or other functions are required. Another application is on positioning steam and fuel-control valves requiring low/high force linear inputs. http://www.woodward.com/turbine/steam/steam2/actuators.cfm Fig. No. 1 TG-13E E/H Actuator Fig. No. 2 UG-UG/40 E/H Actuators ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Basic Working Principle • An electro-hydraulic actuator includes an electric motor that drives a hydraulic pump to move fluid from a reservoir to a hydraulic actuator. When the electric motor is driven in a first rotational direction, the hydraulic fluid moved by the hydraulic pump extends a rod of the actuator. Fig. No. 3. Electrohydraulic Scheme http://www.engnetbase.com//books/774/0066ch20.pdf ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Basic Working Principle • When the electric motor is driven in a second rotational direction, opposite to the first rotational direction, the hydraulic fluid moved by the hydraulic pump retracts the rod of the actuator. Fig. No. 4. Electrohydraulic actuator block diagram http://www.engnetbase.com//books/774/0066ch20.pdf ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

9. Typical Sample Configuration • A typical sample configuration of an electrohydraulic actuator is as turbine and engine control. One example is a proportional actuator for positioning steam and fuel-control valves requiring low/high force linear inputs. This actuator provide one inch of linear movement of valves for steam or gas turbines. The configuration of this actuator is as follows: • Output—linear, 25 mm (1") max stroke, 10.7 kN (2400 lbf) maxInput Power—552 to 8274 kPa (80 to 1200 psig), external supply oil. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

10. Typical Sample Configuration • Another sample configuration is a proportional electrohydraulic actuator which is design to control diesel and gas engines or steam and industrial gas turbines, and particularly is well suited for use in control systems requiring a rotary mechanical output that is proportional to electrical input. Fig. No. 5 TM-55P Proportional Actuator Output—rotary, 45 degrees, 75 J (55 ft-lb) max, position feedback = redundant RVDT/LVDT Input Power—2758 to 6895 kPa (400 to 1000 psig), external supply oil. http://www.woodward.com/turbine/steam/steam2/actuators.cfm ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

11. Major Specifications • Specifications changes on the kind of application required to the actuator, however the major specifications are as follows: - Output Shaft - Work Capacity - Output Force - Hysteresis - Operating Temperature - Drive speed and rotation - Linearity ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

12. Output Shaft • Is the shaft that transmits torque from the actuator to an engine or other device to be controlled by the electrohydraulic actuator. • Typically is a hardened 17-4 stainless steel 0.625-inch (15.88 mm) round, with one-inch square (645 mm²) 17-4 stainless steel rod end attached by 0.375-inch (9.52 mm)/24-threads/inch threads. Optional rod end features 0.625-inch (15.88 mm) slot with 0.500-inch (12.70 mm) hole to pin linkage to valve. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

13. Work Capacity • Is the energy(work) required by the output shaft to do a full travel angle. Standard UG-ACTUATOR 19.4 J (14.3 ft-lb) in the increase direction; 23.3 J (17.2 ft-lb) in the decrease direction. 20 ft-lb UG-ACTUATOR 27.2 J (20 ft-lb) in both directions. Remote UG-ACTUATOR 27.2 J (20 ft-lb) when supplied with 2760 kPa (400 psi); pressurized oil must be supplied to the actuator. Fig. No. 6 UG Maximum work capacity http://www.woodward.com/pdf/ic/37511.pdf ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

14. Output Force • Is the maximum output force required by the electrohydraulic actuator to apply a motion on the output shaft. This parameter varies depending on the application and the load to move. A typical output force parameters for a electrohydraulic (Remote proportional) actuator is (ref. http://www.macmhydraulic.com/products/Dynex/ dynexrpaspecs.pdf) : • 60 lb (0,27 kN) at 200 psi (15 bar) • supply pressure; • 1200 lb (5,33 kN) at 3000 psi • (210 bar) supply pressure. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

15. Hysteresis • Hysteresis is a phenomena with a lot of definitions , electric hysteresis occurs when applying a varying electric field, and elastic hysteresis occurs in response to a varying force. For actuators, hysteresis is sort of a "guard band" around the desired set point of the system. Is a band of tolerance between the maximum and minimum value, avoiding big changes that can cause serious damage on devices. • Usually for electrohydraulic actuators the typical value for the hysteresis is within 3% of the maximum stroke of the shaft. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

16. Operating Temperature • At elevated temperatures a electrohydraulic actuator can fail catastrophically, but even if it doesn't, its electrical and magnetic characteristics frequently undergo intermittent or permanent changes. • Manufacturers of electrohydraulic actuators specify a maximum operating temperature for their products. • This range for a typical electrohydraulic actuator is: –29 to +93 °C ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

17. Drive speed and Rotation • The drive speed and rotation specification is the speed driven by the actuator’s pump. • Actuators are available with either high or low speed pump. • High speed pump: 600 to 1300 rpm. • Low speed pump: 350 to 1000 rpm. Drive operates in one direction only. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

18. Linearity • Linearity is specified as a percentage of full scale (maximum valid input), or as a percentage of the electrohydraulic actuator reading. • For electrohydraulic actuators, the typical value of the linearity is 2.5% of the full stroke. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

19. Limitations The limitations of an electrohydraulic actuator are: • Can leak. • Requires position feedback for repeatability. • Some designs good in compression only. • Expensive. • Large and bulky. • Highly complex. • Requires special engineering. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

20. Purchasing Information • There are diverse types of electrohydraulic actuators depending on which application . The following are purchasing information for electrohydraulic actuator for engine and steam control. This information was obtained from the Woodward web page (www.woodward.com). • UG-40 Actuator (20ft-lb)………………US$6950.00 • PG Actuator …………………………….US$6,505.00 • PGPL Actuator………………………….US$6,438.00 • EHPS Power Servo Actuator….....……...US$21,378.00 This products could be purchased in any of the Woodward distributors around the world (ref. www.woodward.com) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators