Comprehensive System Identification of Ducted Fan UAVs - Cal Poly

Table 3.16 – Actuator Linkage GeometriesSERVOVOLTHORN-HORN(in)SERVOHORN(in)POTHORN(in)CENTER-CENTER(in)MINHORN SERVO INPUT POTMAXMIN(deg)MAX(deg)MIN(10 3 )MAX(10 3 )MINMAXSERVOw/POT @90°DS8417JR94091DS368HS12MGCS-10BB5 3.482 0.994 0.975 3.460 -40° 60° -40.741 34.174 -50 50 1810 3728 91.268°6 3.482 0.994 0.975 3.460 -40° 60° -40.741 34.174 -50 50 1809 3727 91.268°5 3.688 0.757 0.669 3.719 -60° 68° -46.419 30.644 -40 40 1851 3895 87.653°6 3.688 0.757 0.669 3.719 -60° 68° -46.419 30.644 -40 40 1854 3882 87.653°5 3.527 0.495 0.468 3.539 -45° 60° -48.610 32.539 -50 50 2102 4086 88.611°6 3.527 0.495 0.468 3.539 -45° 60° -48.610 32.539 -50 50 2102 4085 88.611°5 3.51 0.509 0.469 3.544 -55° 50° -43.471 39.408 -50 50 1880 3870 86.170°6 3.51 0.509 0.469 3.544 -55° 50° -43.471 39.408 -40 40 1987 3670 86.170°5 3.67 0.504 0.468 3.652 -45° 60° -43.814 39.785 -50 50 1930 3963 92.077°6 3.67 0.504 0.468 3.652 -45° 60° -43.814 39.785 -50 50 1935 3969 92.077°The most non-linear case was observed for the HS12MG where problems with thehorns also resulted in binding and interference at larger deflections. For this reason, themaximum commanded deflection was limited to 80% of the maximum actuatordeflection when testing this actuator.The potentiometer apparatus was located next to Allied Aerospace’s HILsimulation test stand. This utilized the ADC and DAC capabilities of the vehiclehardware to feed the actuators the Pulse Width Modulation (PWM) from the stimulusfiles prepared in accordance with CIFER flight test techniques.The two primary measurements required for the CIFER identification were thesweep commanded into the actuator and the potentiometer reading as a result of theactuator moving. Because of the nature of the recording equipment, calibration factorswere required to convert the input and output signals to degrees. These calibration factorswere determined using the geometries shown in Table 3.16 and are presented in Table3.17.- 60 -