scarakins flip motion
09 Sep 2016 14:56 #80262
by Deckerjwd
Replied by Deckerjwd on topic scarakins flip motion
so the problem is that the math func is not able to return a value greater that 1 or -1 which = +/-180 so the joint 1 and joint 0 can never cross over because this would make a triangle with 1 side that = 0, since we can not divide by 0 the kin drive the joint 0 around so that it can make a triangle with a side greater than 0.
where this code is im not sure, i think it is line 136 though 144, i have change my code to read
acos cant return greater that pi [acos(-1)=3.14...] and if you feed it above 1 [acos(1)=0] you need to make it a negative. while this provides the math to cross 180 deg still looking for the limit that stops the kin from getting to 180 deg i can get close 179.99... but it flip if the step would take me over.
may give up and move arm off center so i never cross this point, but this project has been super fun and educational andypugh thx for all your input
where this code is im not sure, i think it is line 136 though 144, i have change my code to read
rsq = xt*xt + yt*yt;
/* joint 1 angle needed to make arm length match sqrt(rsq) */
cc = (rsq - D2*D2 - D4*D4) / (2*D2*D4);
if(cc < -1) q1 = acos(cc+1) + PM_PI;
else if(cc > 1) q1 = 0 - acos(cc-1);
else q1 = acos(cc);may give up and move arm off center so i never cross this point, but this project has been super fun and educational andypugh thx for all your input
Please Log in or Create an account to join the conversation.
Time to create page: 0.111 seconds