Help to my hexapod walk and implement basic tripod gait

Lynxmotion Legged Robots
1

hi guyz,
I have been working on my hexapod from past 1.5Yrs . I have developed a custom servo controller for the bot and finished with body parts and assembly. Now , the main headache is how do i use my inverse kinematic equations to implement gaits like tripod ?. I have used DH-algo to solve inverse kinematics which is for “a leg” , which works as follows : given the (X,Y,Z) of the tip of a leg that touches ground I get all 3 angles. I do this for all 6 legs.

So , In how many steps(points along the trajectory) do i divide the tripod gait?

I have got this idea currently in my mind :
Lets assume i divide the gait it in 3 steps.

  1. Lift 3 legs up
  2. move the 3 legs touching ground so the bot moves forward
  3. Place other 3 legs down which we lifted in step1
    Goto step 1 and repeat it for other set of 3 legs

Now I pre-calucate the angles and get the angle difference between each step. Then I use linear interpolation to get a smooth and slow movement of servos.

I know this is not the way to do it … so asking you guyz to help me with this.

2

You should study the Phoenix “gait tables”. Define as many or few steps as you need.

Alan KM6VV

3

could you plz give me a link to it ?

4

lynxmotion.com/images/html/proj102.htm

5

Beat me to it!

Alan KM6VV

6

ahh now i get my hexapod walking using 12 step(modded) tripod … but I have hardcoded that :frowning:
@Zenta and @Xan : could you shed more light on how you are using IK/FK so that it performs all complex moves? I mean how do u use the IKBody function => What all u fed to it as parameters and what does it spit out & finally how do use the calculated results from IKBody ? … I fear my IK calculations are wrong… I m terribly confused on “how to use IK for hexapod”