Rotatory Inverted Pendulum Using Arduino

 

ROTATORY INVERTED PENDULUM USING ARDUINO

Ankur Rai

Elton Monteirro

Dept.of Electrical an Electronic! En"ineerin"  NMAMIT#Nitte  NMAMIT#Nitte Uupi# Inia $NM%&EE''()n*a*it.in

 Abstract   —

an inverted pendulum is a pendulum that has its center of mass above its pivot point. It is often implemented with the pivot point mounted on a cart that can move horizontally and may be called a cart and pole as sh show own n in the ph phot oto. o. Mo Most st ap appl plic icat atio ions ns li limi mitt the the pendulum to 1 degree of freedom by affixing the pole to an axis axis of ro rotat tation ion.. Whe Where reas as a normal normal pendulum pendulum is stable when hanging downwards, an inverted pendulum is inherently unstable, and must be actively balanced in order to remai order remain n uprigh upright t this can be done done eit either her by applying a tor!ue at the pivot point, by moving the pivot poin pointt hori horizo zont ntal ally ly as part part of a fe feed edba bac" c" syst system em,, changing the rate of rotation of a mass mounted on the pendu pendulum lum on an axis axis para parall llel el to the the pi pivo vott axis axis an and d thereby generating a net tor!ue on the pendulum, or by os osci cill llat ating ing the the piv pivot ot poin pointt vert vertic ical ally ly.. #h #hee in inve vert rted ed pendulum is a classic problem in dynamics and control theory and is used as a benchmar" for testing control strategies.

I. I NTRODU,TION  A penul penulu* u* i! an in-er in-erent entl l !ta !ta/le /le ! !!te !te* * !in !ince ce if no e0ternal force! are applie to it 1ill co*e to re!t -an"in" irectl it! pi2ot point. T-i! i! al!o calle t-e e3uili/riu* !tate of t-e penulu*.

4i" % A Si*ple Penulu*

Dept.of Electrical an Electronic! En"ineerin" NMAMIT#Nitte NMAMIT#Nitte Uupi# Inia   $NM%&EE'+')na*a*it.in  $NM%&EE'+')na*a*it.in 

T-e in2erte penulu* con!i!t! of t-e !a*e ele*ent! a! t-e  penulu* /ut place up!ie o1n. o1n. 5-ere tt-ee nor*al  penulu* i! in-erentl !ta/le !ta/le !ince it "oe! to1ar e3uili/riu* if no e0ternal input! are pro2ie# t-e in2erte  penulu* i! in-erentl un!ta/le un!ta/le !ince it! e3uili/riu*  po!ition i! i!rupte if no e0ternal e0ternal input i! pro2ie to keep it in place.

4i" + In2erte Penulu* A co**on 1a to 2i!uali6e an in2erte penulu* i! to t-ink  of a per!on /alancin" a !tick on t-e pal* of t-eir -an. If no correction i! applie / *o2in" t-e -an# t-en t-e !tick 1ill ine2ita/ ine2 ita/l l fall o2er. T-i! *ean! t-at an !! !!te* te* 1-i 1-iccre!e re!e*/ */le le!! t-e t-e -an -an7! 7!ti tick ck7! 7!! !te te* * i! in nee nee of ac acti ti2e 2e *oni *o nito tori rin" n" an an  co cont ntro roll to keep keep it !t !ta/ a/le le.. T-e T-e *a8o *a8or  r  ifference fro* t-i! to t-e in2erte penulu* t-at 1ill /e u!e in t-i! paper i! t-at it i! re!tricte to *o2e*ent aroun a !in"le a0i! 1-erea! t-e !tick can fall in all irection! fro* it! !tanin" po!ition.

 

4i" & 9roo* Stick 9alancin" T-e in2erte penulu* -a! /een a cla!!roo* e0a*ple in control en"ineerin" en"ineerin" for *an ear! !ince it *ake! for a "oo e0erci!e in *an of t-e !kill! neee in a cour!e on t-e !u/8ect.  

ar* an t-e *otor keep! t-e in2erte penulu* upri"-t / *o2in" t-e 1-eel! analo"ue! to "eneratin" tor3ue at t-e  pi2ot point >1-ic- in t-e !i*ple e0a*ple of keepin" a !tick   place in t-e pal* of our upri"-t con!i!t in *o2in" t-e -an /ack an fort-?. In t-i! ca!e t-e rocket /o i! e3ui2alent to t-e penulu* ar* an t-e tor3ue i! applie at /a!e of t-e rocket 2ia t-e rocket en"ine!. Ser2o *otor i! a !i*ple electrical *otor # controlle 1it- t-e -elp of !er2o*ec-ani!*. If t-e *otor a! controlle e2ice# a!!ociate 1it- !er2o*ec-ani!* i!  i! D, *otor # t-en it i! co**onl kno1n D, Ser2o Motor. If t-e controlle *otor i! operate / A,# it i! calle A, Ser2o Motor. T-ere are !o*e !pecial tpe! of application of electrical *otor 1-ere rotation of t-e *otor i! re3uire for 8u!t a certain an"le not continuou!l for lon" perio of ti*e. 4or t-e!e application!#  are re3uire 1it- !o*e !pecial !o*e !pecial  !pecial tpe! of *otor  are arran"e*ent 1-ic- *ake! t-e *otor to rotate a certain an"le for a "i2en electrical input >!i"nal?. 4or t-i! purpo!e !er2o *otor co*e! into picture. T-i! i! nor*all a !i*ple D, *otor 1-ic- i! controlle for !pecific an"ular rotation 1itt-e -elp of aitional !er2o*ec-ani!* >a tpical clo!e loop fee/ack control !!te*?.

4i" $ Rotar In2erte Penulu* So*eti*e! t-e penulu* i! attac-e to a cart# ot-er ti*e! to So*eti*e! a ro 1-ic- i! it!elf attac-e to a *otor# an ot-er ti*e! !till t-e penulu* it!elf i! attac-e to t-e a0le of a *otor. No *a *atte tterr -o1 t-e in in2er 2erte te pe penu nulu* lu* ! !!te !te* * i! /uilt /uilt tt-ee  pro/le* i! t-e !a*e: it 1ill /e in-erentl un!ta/le an t-erefo t-er efore re !o*e !o*e for* for* of control control *u!t /e i*ple*e i*ple*ente nte in orer to *ake !ure t-at t-e t -e penulu* re*ain! in t-e 2ertical upri"-t po!ition in!tea of fallin" ue to "ra2it an ot-er  i!tur/ance!.

4i" ( Ser2o Motor 

4i" @ Gro!copic Sen!or MPU initiali6e Serial.println>initiali6e MP MPU?K U?K   *pu.initiali6e>?K Serial.println>*pu.te!t,onnection>?,onnecte:,onnecti on faile?K   initiali6e !er2o!

Al"orit-* for t-e I*ple*entation of t-e S!te* Step %: Po1er up t-e e2ice Step +: Initiali6e t-e li/rarie! Step &: Set t-e !er2oF! at initial po!ition Step $: ,-eck 1-et-er "ro!cope i! rea Step ;: 5ait for t-e "ro!cope interrupt Step %'?K  2oi loop>?    rea !en!or 2alue!   *pu."etMotionQa0#Qa#Qa6#Q"0#Q"#Q"6?K  

2alC*ap>7a#7%('''#%('''#'#%(?K

 

2al%C*ap>a0#7%('''#%('''#'#%(?K

 

output of !er2o *!er2o.1rite>2al?K

Pro"ra* Structure /uilt in li/rarie! HinclueSer2o.-J Hinclue5ire.-J HinclueI+,e2.-J HinclueMPU