S 6 th h o I n r t t e C r o n u a r t i s o e n a o l n P E l a x n t r e e t High Temperature Mechanisms m High Temperature Mechanisms a r e y E P n A Breakthrough Development r o v b i r e o n W m o e r n k t s s h T o p e , c h A n Jerri Ji t l o a l n o t g a Honeybee Robotics Spacecraft Mechanisms Corporation i , e G s e New York, NY o r g i a 0 6 / 2 2 1 0 - 2 0 2 8 Page 1 Overview S • Introduction 6 th h o I n r t t e C • High Temperature Mechanisms r o n u a r t i s o e – High Temperature Switched Reluctance Motor n a o l n P E l – High Temperature Drill a x n t r e e t m – High Temperature Brushless DC Motor & Resolver a r e y E P n r o v b • Summary & Conclusions i r e o n W m o e r n k t s s h T o p e , c h A n t l o a l n o t g a i , e G s e o r g i a 0 6 / 2 2 1 0 - 2 0 2 8 Page 2 Introduction • The extreme high temperature /high pressure environments on S 6 th h o I Venus are unique compare with other NASA Solar System n r t t e C r o exploration mission, environment condition is 460C, 90 bar, 97% n u a r t i s CO2 at the Venus surface, sulphuric acid clouds at 50 km o e n a o l n P • No exist off-the-shelf motors or known R&D prototype motors are E l a x n t r capable of operating under Venus surface conditions for any e e t m a r e appreciable amount of time y E P n r o v • Two types of high temperature motor have been developed by b i r e o n W Honeybee Robotics: m o e r n k t s – HT Switched Reluctance Motor s h T o p e , • Completed Phase I & II study (2.5 years) c h A n t l o a l n • Final prototype was used to actuate a high temperature drill o t g a i , e G – HT DC Brushless Motor and Resolver s e o r • Completed 6 month study (Phase I) g i a • Next generation BLDC motor along with high temperate 0 sample acquisition scoop and high temperature joint are 6 / 2 2 1 0 under development in Phase II study - 2 0 2 8 Page 3 Switched Reluctance Motor • The switched reluctance motor is a direct current, brushless electric S 6 th motor. h o I n r t t e • It has salient poles on both the rotor and stator, but only the stator C r o n u carries windings. The rotor has no windings, magnets, or cage a r t i s o e n winding. a o l n P • Both the rotor and the stator are built up from a stack of magnetic- E l a x n t alloy, salient-pole laminations. r e e t m a r e • The operating principle of SRMs is based on the tendency of a rotor y E P n pole pair to align with the energized stator pole pair. r o v b i r e o n W m o e r n k t s s h T o p e , c h A n t l o a l n o t g Rotor a i , e G s e Stator o r g i a Stator 0 Windings The four current phases 6 / 2 2 1 are listed as A, B, C and 0 - 2 0 2 D, with A-A’, etc., being a 8 pole pair. Page 4 Switched Reluctance Motor • The SRM design uses materials and components selected based on S 6 th the requirement to survive above 460°C, at earth atmosphere. h o I n r t t e C r o n u a r t i s o e n a o l n P E l a x n t r e e t m a r e y E P n r o v b i r e o n W m o e r n k t s s h T o p e , c h A n t l o a l n o t g a i , e G s e o r g i a 0 6 / 2 2 1 0 - 2 0 2 8 Page 5 Switched Reluctance Motor • The prototype motor performance is mainly driven by the S 6 th requirements of future Venus drilling and sampling systems (weight- h o I n r t t on-bit, auger rotation speed, etc.) and robotic arms (payload mass, e C r o reaction loads, positioning requirements, etc.) n u a r t i s o e • It has been operated non-continuously for over 20 hours at Venus- n a o l n like conditions (460°C temperature, mostly CO2 gas environment) P E l a and is still functioning properly. x n t r e e t m a r e y E P n r o v b i r e Speed/Torque Gradiant at 48V Torque/Current Gradiant48V o n W m o 6.00 e 9000 r n k t s s 8000 h 5.00 T o p 7000 e , c h A ) 4.00 s ) 6000 n t p M l o a m P A 5000 l n R ( o ( 3.00 t t g d n a e e 4000 i r , e e r p u G s S C 2.00 3000 e 2000 o r 1.00 g i 1000 a 0 0.00 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Torque (Oz-In) 0 Torque (Oz-In) 6 / 2 2 1 0 - 2 0 2 8 Page 6 HT Switched Reluctance Motor • Since the Maxon RE-25 motor has been used to actuate various S 6 th prototype drills system developed by Honeybee Robotics and a flight h o I n r t t version of the Maxon RE-25 is the largest motor used on the Mars e C r o Exploration Rover mission, some of the Maxon motor’s performance n u a r t i s o characteristics provide a reasonable comparison for high e n a o l temperature motor. n P E l a • All test data are from motor test controlled by a custom controller x n t r e e t m which we are still optimizing. a r e y E P n Maxon SRM r o v b i r e RE-25 * Prototype o n W Characteristics Units m o e Range Range r n k t s s at 25°C at 460°C h T o p e , c Applied Voltage V 4.5 - 48 20 - 48 h A n t l o a l n Maximum Speed Rpm 5500 7500 o t g a i , e G No-Load Speed rpm 4790 - 5500 7000-7500 s e o r No-Load Current mA 7 - 80 1000-1200 g i a Stall torque mNm 119 - 144 200 – 250 0 6 / 2 2 1 0 Motor Characteristics Comparison of Existing Maxon RE-25 to Current SRM Prototype - 2 0 2 *Maxon DC Motor, RE-25 mm,” 8 http://test.maxonmotor.com/docsx/Download/catalog_2008/Pdf/08_077_e.pdf Page 7 High Temperature Drill • The prototype high temperature drill S 6 th h can operate with low thrust reaction o I n r t t e in low gravity environment. C r o n u a r t i • Overall envelope is 6.8 inch x 4.3 s o e n a inch x 18.8 in with 10 inches of drill o l n P E l stroke. (system was designed to fit a x n t r e e existing test chamber). t m a r e y E • Two high temperature switched P n r o v b reluctance motors were integrated i r e o n W into the system to actuate the Z and m o e r n Auger axes. Both were driven by k t s s h T the custom controller Honeybee has o p e , c h developed using sensorless control A n t l o a l n algorithm. o t g a i , e G • All components of the drill including s e o gears, bearings and bushings were r g i selected based on the requirement a to survive above 460°C, at earth 0 atmosphere. 6 / 2 2 1 0 - 2 0 2 8 Page 8 High Temperature Drill S 6 th h o I n r t t e C r o n u a r t i s o e n a o l n P E l a x n t r e e t m a r e y E P n r o v b i r e o n W m o e r n k t s s h T o p e , c h A n t l o a l n o t g a i , e G s e o r g i a 0 6 / 2 2 1 0 - 2 0 2 8 Page 9 High Temperature Drill • The high temperature drill conducted three drilling tests at Venus-like S 6 th conditions (460°C temperature, mostly CO2 gas environment) h o I n r t t successfully drilled into chalk to 6 inches deep in each test.