Table 1 Precision comparison with other works.

From: Trimmed helicoids: an architectured soft structure yielding soft robots with high precision, large workspace, and compliant interactions

 

Method

Length (cm)

Actuation of each section

Section number

Error (mm)

Error/Length

Test data

Control Method

Data input

Li (2021)45

Closed-loop & Learning

Q-learning Pretrained with Simulator

Simulator and multi-iteration static points

63.0

3-Dofs of pneumatics

4

23 (200 s)

3.7%

Points to points

You (2017)46

 

Q-learning

Multi-iteration static points

63.0

2-Dofs of pneumatics

4

8 (2D)

1.3%

Centurelli (2021)47

Open-loop & Learning

Artificial Neural Network (ANN)

Static points

20

3 DoFs of pneumatics

1

10.6

5.3%

Trajectory tracking

Trust Region Policy Optimization (TRPO)

Static points and Dynamic trajectories

3.2

1.6%

Satheeshbabu (2019)48

Reinforce-ment Learning

Static points

31

3-Dofs of pneumatics

1

< 29.8

9.6%

Points to points

Chen (2016)49

K-nearest- Neighbors Regression (KNNR)

Dynamic trajectories

6.3

2 DoFs of tendon-driven and 1 DoF of screw-driven

1

2.15

3.4%

Trajectory tracking

Marchese (2014)50

Closed-loop

PID control

Geometry and captured trajectories

23.0

1 DoFs of pneumatics

6

7.1 (2D)

3.1%

Points to points

Liu (2017)28

Open-loop

Static model

Geometry and mechanics

25.5

3-Dofs of tendon-driven

1

3.8-9.5

1.5- 3.7%

Points to points

Our work

Inverse static model based on non-constant strain kinematics

Geometry and mechanics

87.7

3 DoFs of tendon-driven

3

4.8%

4.8%

Trajectory tracking