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

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KIN_TYP_12 – Tripod kinematics 1:
Tripod kinematics
KIN_TYP_12 – Tripod kinematics 2:
Vector representation of strut kinematics
KIN_TYP_12 – Tripod kinematics 3:
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 of column / joint 3 to column / joint 1

1.0 E-4°

HD10

9

Angle of column / joint 3 to column / joint 2

1.0 E-4°