OK so I'm brand new to the hole robotics and programing thing.
I have been doing a lot of reading on programing and how it works and are slowly starting to
understand it. But it has been prity slow going for me. What you got to under stand is that
I'm not a real computer person unlike a lot of the readers on this forum, but i am trying to be.
My first question of what will probably be many questions to come. Is it really this simple.
Now i have the code for the Phantom X (AKA 6 leged robot) and i am wondering if it is realy as
simple as i think it is to change it to a 8 leg robot code. Or am i just being naive about this
and i need to spend a lot more time reading about things.
OK for my first example i would like to show.
================================================== ==============================================
#define LEG_COUNT 6
/* Body
* We assume 4 legs are on the corners of a box defined by X_COXA x Y_COXA
* Middle legs for a hexapod can be different Y, but should be halfway in X
*/
#define X_COXA 60 // MM between front and back legs /2
#define Y_COXA 60 // MM between front/back legs /2
#define M_COXA 100 // MM between two middle legs /2
/* Legs */
#define L_COXA 52 // MM distance from coxa servo to femur servo
#define L_FEMUR 82 // MM distance from femur servo to tibia servo
#define L_TIBIA 140 // MM distance from tibia servo to foot
================================================== ==============================================
*first thing that comes to attention is the define leg count. simply change that to 8.
*now on to the body. so i now have a new set of legs that need to be plumed in. Now X= front legs
and back legs that making our mid legs Y. Is it as simple as this
x= front legs
xy=mid legs
yx=mid legs
x=back legs
#define X_COXA 60 // MM between front and back legs /2
#define Y_COXA 60 // MM between front/back legs /2
#define XY_COXA 100 // MM between two middle legs /2
#define YX_COXA 100 // MM between two middle legs /2
I hope i have not lost you yet with the questions.
Now the next part of the code seems pretty ezy.
--------------------------------------------------------------------------------------------------
/* Servo IDs */
#define RM_TIBIA 18
#define RF_COXA 2
#define LR_TIBIA 11
#define LF_FEMUR 3
#define RF_TIBIA 6
#define RM_FEMUR 16
#define RM_COXA 14
#define RR_COXA 8
#define LF_TIBIA 5
#define LF_COXA 1
#define LR_FEMUR 9
#define RR_FEMUR 10
#define LM_TIBIA 17
#define RF_FEMUR 4
#define LM_FEMUR 15
#define RR_TIBIA 12
#define LM_COXA 13
#define LR_COXA 7
--------------------------------------------------------------------------------------------------
In this part of the code it shows each of the 18 servos that are used and where they are used on
the hex. Can i just simply duplicate all the mid leg servos and then change the servo number to
the right one. So it would look like this.
24 servos
/* Servo IDs */
#define RM_TIBIA 18
#define RF_COXA 2
#define LR_TIBIA 11
#define LF_FEMUR 3
#define RF_TIBIA 6
#define RM_FEMUR 16
#define RM_COXA 14
#define RR_COXA 8
#define LF_TIBIA 5
#define LF_COXA 1
#define LR_FEMUR 9
#define RR_FEMUR 10
#define LM_TIBIA 17
#define RF_FEMUR 4
#define LM_FEMUR 15
#define RR_TIBIA 12
#define LM_COXA 13
#define LR_COXA 7
#define LM_COXA 19
#define RM_COXA 20
#define LM_FEMUR 21
#define RM_FEMUR 22
#define LM_TIBIA 23
#define RM_TIBIA 24
----------------------------------------------------------------------------------------------
/* Actual positions, and indices of array. */
extern ik_req_t endpoints[LEG_COUNT];
#define RIGHT_FRONT 0
#define RIGHT_REAR 1
#define LEFT_FRONT 2
#define LEFT_REAR 3
#define RIGHT_MIDDLE 4
#define LEFT_MIDDLE 5
----------------------------------------------------------------------------------------------
Above is the original code. Mine would simply be.
/* Actual positions, and indices of array. */
extern ik_req_t endpoints[LEG_COUNT];
#define RIGHT_FRONT 0
#define RIGHT_REAR 1
#define LEFT_FRONT 2
#define LEFT_REAR 3
#define RIGHT_MIDDLE 4
#define LEFT_MIDDLE 5
#define RIGHT_MIDDLE 6
#define LEFT_MIDDLE 7
I gess that's about it for the first part of questions.
Below i pasted the original code that is unchanged
-------------------------------------------------------------------------------------------
/************************************************** ****************************
* Inverse Kinematics for 4/6 legged bots using 3DOF lizard legs
*
* Auto-Generated by NUKE!
* http://arbotix.googlecode.com
*FRONT VIEW ^ ==0 0==
* /\___/\ | | 0==[___]==0 |
* / \ Z | |
*
* TOP VIEW
* \ / ^
* \_____/ |
*___| |___ X
* |_____|
* / \ Y->
* / \
************************************************** ***************************/
#ifndef NUKE
#define NUKE
#define LEG_COUNT 6
/* Body
* We assume 4 legs are on the corners of a box defined by X_COXA x Y_COXA
* Middle legs for a hexapod can be different Y, but should be halfway in X
*/
#define X_COXA 60 // MM between front and back legs /2
#define Y_COXA 60 // MM between front/back legs /2
#define M_COXA 100 // MM between two middle legs /2
/* Legs */
#define L_COXA 52 // MM distance from coxa servo to femur servo
#define L_FEMUR 82 // MM distance from femur servo to tibia servo
#define L_TIBIA 140 // MM distance from tibia servo to foot
/* Servo IDs */
#define RM_TIBIA 18
#define RF_COXA 2
#define LR_TIBIA 11
#define LF_FEMUR 3
#define RF_TIBIA 6
#define RM_FEMUR 16
#define RM_COXA 14
#define RR_COXA 8
#define LF_TIBIA 5
#define LF_COXA 1
#define LR_FEMUR 9
#define RR_FEMUR 10
#define LM_TIBIA 17
#define RF_FEMUR 4
#define LM_FEMUR 15
#define RR_TIBIA 12
#define LM_COXA 13
#define LR_COXA 7
/* A leg position request (output of body calcs, input to simple 3dof solver). */
typedef struct{
int x;
int y;
int z;
float r;
} ik_req_t;
/* Servo ouptut values (output of 3dof leg solver). */
typedef struct{
int coxa;
int femur;
int tibia;
} ik_sol_t;
/* Actual positions, and indices of array. */
extern ik_req_t endpoints[LEG_COUNT];
#define RIGHT_FRONT 0
#define RIGHT_REAR 1
#define LEFT_FRONT 2
#define LEFT_REAR 3
#define RIGHT_MIDDLE 4
#define LEFT_MIDDLE 5
extern BioloidController bioloid;
/* Parameters for manipulating body position */
extern float bodyRotX; // body roll
extern float bodyRotY; // body pitch
extern float bodyRotZ; // body rotation
extern int bodyPosX;
extern int bodyPosY;
/* Parameters for gait manipulation */
extern int Xspeed;
extern int Yspeed;
extern float Rspeed;
extern int tranTime;
extern float cycleTime;
extern int stepsInCycle;
extern int liftHeight;
extern int step;
/* Gait Engine */
extern int gaitLegNo[]; // order to move legs in
extern ik_req_t gaits[]; // gait position
/* convert radians to a dynamixel servo offset */
int radToServo(float rads);
/* select a gait pattern to use */
void gaitSelect(int GaitType);
#include "gaits.h"
/* find the translation of the coxa point (x,y) in 3-space, given our rotations */
ik_req_t bodyIK(int X, int Y, int Z, int Xdisp, int Ydisp, float Zrot);
/* given our leg offset (x,y,z) from the coxa point, calculate servo values */
ik_sol_t legIK(int X, int Y, int Z);
/* ties all of the above together */
void doIK();
/* setup the starting positions of the legs. */
void setupIK();
#endif
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