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Table 3 The comments of the symbols

From: Obstacle avoidance planning of space manipulator end-effector based on improved ant colony algorithm

System CM

The system’s center of gravity

\(\sum {\text{I}}\)

The inertial coordinate system

B 0

Base of the system

B i (i = 1,2…,7)

The ith link

\(J_{i}\)

The ith joint

\(C_{i}\)

Gravity center of B i

\({\varvec{a}}_{i}\)

Position vector from J i to C i

\({\varvec{b}}_{i}\)

The distance from C i to \(J_{i + 1}\)

\({\varvec{b}}_{0} \in {\mathbf{R}}^{3}\)

Position vector from CM of base to joint 1

\({\varvec{r}}_{b} \in {\varvec{R}}^{3}\)

Position vector of the center of mass (CM) of base

\({\varvec{r}}_{i} \in {\varvec{R}}^{3} \left( {i = 1,2, \ldots ,7} \right)\)

Position vector of CM of link \(i\)

\({\varvec{r}}_{g} \in {\varvec{R}}^{3}\)

Position vector of the system

\({\varvec{r}}_{e} \in {\varvec{R}}^{3}\)

Position vector of end-effector

\({\varvec{p}}_{i} \in {\varvec{R}}^{3}\)

Position vector of joint \(i\)

\({\varvec{p}}_{i}\)

Position vector of \(J_{i}\)

\(\alpha_{i - 1}\)

The link corner of manipulator

\(a_{i - 1}\)

The length of common vertical line from the joint shaft \(i - 1\) to i

d i

The link offset

θ i

The ith joint angle

\({\varvec{\varTheta}} \in {\varvec{R}}^{n}\)

Joint angle vector

m i

Mass of link i

l i

Length of the ith link

I

Movement inertia of the links