Datawell BV Hippy 40-MkII Manual Download Page 1

 

March 20, 2019 

 

Datawell Heave Pitch Roll Sensor

 

Manual

 

 

Hippy 40-MkII

 

 

from serial no. 18181 

Service & Sales 

Voltastraat 3 
1704 RP Heerhugowaard 
The Netherlands 

 +31 72 534 5298 

 +31 72 572 6406 

www.datawell.nl 

Summary of Contents for Hippy 40-MkII

Page 1: ...March 20 2019 Datawell Heave Pitch Roll Sensor Manual Hippy 40 MkII from serial no 18181 Service Sales Voltastraat 3 1704 RP Heerhugowaard The Netherlands 31 72 534 5298 31 72 572 6406 www datawell nl...

Page 2: ...2...

Page 3: ...13 7 Transportation 14 8 Specifications 15 8 1 General 15 8 2 Pitch roll 16 8 3 Heave 17 8 4 Acceleration 18 9 System check and calibration heave 19 9 1 Simple System check 19 9 2 Calibration 19 10 Sy...

Page 4: ...4 fig 1...

Page 5: ...asurements is a gravity stabilised platform with a natural period time of 40 seconds An accelerometer is mounted on this stabilised platform The sensor can accept any voltage between 10 and 30 V DC Ou...

Page 6: ...r for heave measurement 2 2 The heave is obtained by double integrating the acceleration Temporary offset of the platform caused by horizontal acceleration varying ship s speed leads to false accelera...

Page 7: ...ls A and B fixed to housing and perpendicular to each other A pickup coil C mounted on the stabilised platform horizontal plane measures the vertical components of H1 and H2 fig 2 and 3 The induced vo...

Page 8: ...of both planes Angle between both planes is Be H1 P the magnetic field vector generated parallel to the pitch axis OP1 the projection of OP on horizontal plane Component of H1 perpendicular to Vh PP1...

Page 9: ...p sin ROR1 sin cos For scale factor see specifications 8 2 angle between instrument plane and horizontal plane angle between pitch axis and rotation axis POP1 angle between pitch axis and horizontal p...

Page 10: ...Supply junction box terminal no 2 pitch junction box terminal no 3 roll junction box terminal no 4 Outputs heave junction box terminal no 5 acceleration junction box terminal no 6 common junction box...

Page 11: ...xis are indicated by V formed cuttings in the rim of the bottom flange Mount the instrument with arrow on text plate on lid in the direction of the bow of the ship see fig 10 V formed cuttings in lid...

Page 12: ...lane r in volts 10 sin 2 Output is positive if port side of ship is lifted The mast angle equal to angle between base plane and horizontal plane can be derived from both outputs according to 2 2 2 sin...

Page 13: ...0 seconds is s 400 radian s peak value of horizontal displacement m For sudden changes in ship s speed v m sec is v 60 radian Platform orientation 6 3 The pitch roll measurement is independent of the...

Page 14: ...r example when it is being hoisted may damage the accelerometer beyond repair The Hippy should not make more than six revolutions in two minutes Spinning may also lead to an entangled suspension of th...

Page 15: ...Any voltage between 10 30 V DC 180 mW Maximum source impedance 50 Input capacitance 470 F Maximum permissible voltage between output battery and chassis 380 V Supply unit is protected against reverse...

Page 16: ...an horizontal plane Eu 10 sin volts see fig 3 Bandwidth Low pass third order filter up to 1 Hz amplitude transfer within 1 linear phase shift equal to 0 06 seconds up to 5 Hz within 6 dB Scale accura...

Page 17: ...accuracy gain error 0 5 of measured value after calibration 1 0 of measured value after 3 year Zero offset Below 30 cm 300 mV typically 3 cm Zero stability See under 8 2 Pitch roll Noise Below 1 cm p...

Page 18: ...ange 10 m sec Output at terminal 6 is positive for upward acceleration Bandwidth Low pass third order filter up to 1 Hz linear phase shift equal to 0 06 sec up to 5 Hz within 6 dB Scale accuracy gain...

Page 19: ...ending the Hippy from springs e g extenders that can be bought in a sports shop The low mechanical losses of the resulting mass spring resonant system allow one to maintain a constant amplitude oscill...

Page 20: ...s to be 20 V 0 4 V The same applies for the roll output at roll angles of and 90 pitch axis vertical Zero offset Zero offset is equal to measured output if instrument is placed on horizontal plane Bas...

Page 21: ...21 fig 5...

Page 22: ...ition on top of the adjustment bolts A1 A2 A3 and A4 but with the bolts B unfixed yet Screw the bolts A1 and A3 down so that the instrument can rotate around the axis A2 A4 like a seesaw Press the ins...

Page 23: ...23 fig 6...

Page 24: ...e The fluid in which the stabilised platform is suspended however contains water which can diffuse very slowly through the wall of the sphere To prevent a 100 relative humidity and condensation two 65...

Page 25: ...25 fig 8...

Page 26: ...offset For example If radius of circle 2 cm Sensitivity of xy recorder 100 mV cm Sensitivity of Piro 174 mV Platform offset 2x100 174 1 15 If no xy recorder is available write pitch and roll output o...

Page 27: ...responding 0 via a straight line The pitch and roll outputs should be below 0 3 50 mV if sensitivity is standard The acceleration output should be below 0 1 m sec2 0 1 V If not in order remove green a...

Page 28: ...o the square of the frequency of the generator II Non standard sensitivity If the sensitivity is not standard there may be resistors between stand off s on pcb parallel to R157 and R158 R157a R158a R1...

Page 29: ...resistors except R22a have to be transferred For R22a a new value has to be calculated from the value of R22a in the old pcb as follows R22a new R22a old 78 KOhm Picking a value for R22a from the E 9...

Page 30: ...nd arrow under print pointing towards marking in the flange 2 Silicagel bags should not be in direct contact with pcb Place them in special compartments within bag see fig 6 Seal the polyethylene bag...

Page 31: ...ly checked through perspex lid on sphere If centre of rubber membrane is pointing upwards see fig 9 B level is sufficient In case the membrane touches division plate see fig 9 A fluid has to be added...

Page 32: ...first page manual 18001 Original 18003 Flattened flanges of can electronics changed 18033 Dimensions of housing changed Zero offset of acceleration changed into 1m sec MkII added 18121 Pcb 18 9A intr...

Page 33: ...33 15 Dimensions and connections fig 10...

Page 34: ......

Page 35: ...A 1 Appendix fig 8a...

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