KIN_TYP_12 – Tripod kinematics

Kinematic structure

The strut kinematic structure (referred to as “tripod”) consists of 3 translatory axes in a non-Cartesian arrangement. Strut pairs parallel to each other carry the tool holder platform. Tool orientation is constant.

Axis configuration in the NC channel

Axis identifier

X, Y, Z (Z1, Z2, Z3)

Axis index

0, 1, 2

Kinematic structure

 

Tool axes

Workpiece axes

NC axes

X, Y, Z

-

Tripod kinematics
Tripod kinematics
Vector representation of strut kinematics
Vector representation of strut kinematics
Offset dimensions of strut kinematics
Offset dimensions of strut kinematics

The parameter HD8 is used to toggle between an ideal (1) and non-ideal (0) tripod. An ideal tripod has an angle of 120° between all columns. A non-ideal tripod must be defined by the angles HD9 and HD10.
The third angle between columns is calculated as follows:

W_Z1Z2 = 360° - HD9 – HD10 = 360° - W_Z2Z3 – W_Z1Z3

Offset data of kinematics

HD offset

param[i]

Description

Unit

HD1

0

Tool offset Z

1.0 E-4 mm

HD2

1

Tool offset Y

1.0 E-4 mm

HD3

2

Tool offset X

1.0 E-4 mm

HD4

3

Z axis offset machine origin

1.0 E-4 mm

HD5

4

Radius to connecting line of the joint centre points on the drive columns (large circle)

1.0 E-4 mm

HD6

5

Radius to connecting line of the joint centre points on the holder platform (small circle)

1.0 E-4 mm

HD7

6

Strut length to each joint centre point

1.0 E-4 mm

HD8

7

Switch to switch over to non-ideal tripod
0 : ideal tripod
1 : non-ideal tripod and enable HD9 / HD 10

[ - ]

HD9

8

Angle column / joint 3 to column / joint 1

1.0 E-4°

HD10

9

Angle column / joint 3 to column / joint 2

1.0 E-4°