hi andy, any progress about that document? we’re looking forward to see them:-)
Hi sorry about the delay, I’ve ended up doing more stuff with work and was away for a few days, will hopefully get chance to finish it this week.
Andy
all looking forward to see it:-) wish you success…
Here’s how you can solve the theta_f from equation 6. 8)
It could be more details, but writing down the equation in text is really time consuming. My respect goes to Umar for his time spent on writing down the lengthy equation.
img401.imageshack.us/img401/5768/trigonometrylinearcombijn7.jpg
img401.imageshack.us/img401/trigonometrylinearcombijn7.jpg/1/w742.png
hi tnay,
I am surprised to learn that eventually someone took the pain for looking into it. I really appreciate your concern.
The way you solved for theta(f) seems logical, i’ll work out my calculations on your methadology and will update the IK.
Thanks again buddy,
umar
Once you got theta(f), you can solve for theta(t) from equation 2,
Take row 2, column 4, you can easily solve theta(t).
This calculation is too intense for normal 8-bit microcontroller, may need several controller to compute the IK in realtime. I’m not familiar with SSC32. Can she handle it?
Then again, SSC32 is already loaded with hexapod walking gait, isn’t it?
Hi All,
I just wanted to update my work in my hexapod project I had been doing for the last few months.
I have reworked the whole IK and Gait routines in SimMehcanics, a Matlab mechanical Simulation toolbox which simulates a CAD Assembly imported from ProEngineer WildFire 4 in real time using Joint & Body Kinematics and Dynamics techniques. The Robot Kinematics model includes the IK routines driving each joint in the simulation.
Furthermore, I have reworked the gaits which have already been developed by many people here. In this respect Zenta’s PEP & Xan’s Phoenix Code has helped me alot in understanding the methodology behind gait sequences, so a big thanks to Zenta and Xan as an acknowledgment from this project.
Below is a video of the robot driven from Matlab Simulation showing some body moves and gait implementation.
Another modification includes the interfacing of PS2 joystick within the Matlab Simulation as user input controller. The PS2 controller is connected to the laptop via PS2-to-USB interface adapter and then read into matlab. PS2 controller provides excellent human interface control to drive the robot in diagonal and straight lines using the analogue sticks with different gaits and speed.
The last and the most important modification is the installment of 4.6A battery pack made from AA cells and positioning of the 2.8A lynxmotion battery pack inside the robot body, which really was a tough task to accomplish. To make it work, the SSC-32 board is screwed with the smallest spacers possible below the upper deck and a custom 2mm fibreglass plate is screwed below the SSC-32 which separates the SSC-32 from the battery, an essential thing to do for charging the battery within the robot body.
Finally, two bright LEDs for servo power and electronics power separately and a 3mm fiberglass plate screwed at the top to cover the wires and the AA battery pack. Future work may involve the dynamic simulation of the robot and probably some sensors integration.
Your comments,suggestions and compliments are welcomed 
Thanks
~Umar
~Umar
The quality of your movements is so smooth. It was fascinating to watch.
EDIT, fixed embarrassing typo
Thanks SN96 for the appreciation
cheers
Umar
Hi Umar,
I totally agree! Smooth moves!
Did you redo the IK calculations or are you using a IK model that’s already on the web?
Keep up the good work!
Xan
Thanks Xan for the appreciation.
I worked out the IK calculations using Denavit-Hartenburg Principle, “a technique which uses advanced matrices to solve serial/parallel manipulators”.So, the intermediate steps are different but the resulting equations are exactly the same as seen in your code or through zenta’s PEP. So, i believe there should not be much difference from the rest of the IK snippets available on web as well. However, DH-Rule holds high significance while determining the dynamics of a manipulator or rigid bodies and thus highly suggestible. I am looking forward to it as my future next immediate goal.
Xan, I must add that the “Timer” methodology you have added in your code for the GAIT part is the key to fluid like movements. And I really appreciate the efforts of the people who contributed in its implementation.
cheers!
Hi Umar,
tnay solved the IK question on the post Dec 01, 2008. Unfortunatelly now the second picture has already been deleted.
Could you or anybody upload it again? It would be a big help for me.
thank you in advance! Franz