Authors: Xudong Wang, Zebin Han, Zhiyu Liu, Gan Li, Jiahua Dong, Baichen Liu, Lianqing Liu, Zhi Han
Organizations: State Key Laboratory of Robotics and Intelligent Systems, Shenyang Institute of Automation, Chinese Academy of Sciences · University of Chinese Academy of Sciences · North University of China · Southeast University · Mohamed bin Zayed University of Artificial Intelligence
Traditional language-conditioned manipulation agent sequential adaptation to new manipulation skills leads to catastrophic forgetting of old skills, limiting dynamic scene practical deployment. In this paper, we propose SkillsCrafter, a novel robotic manipulation framework designed to continually learn multiple skills while reducing catastrophic forgetting of old skills. Specifically, we propose a Manipulation Skills Adaptation to retain the old skills knowledge while inheriting the shared knowledge between new and old skills to facilitate learning of new skills. Meanwhile, we perform the singular value decomposition on the diverse skill instructions to obtain common skill semantic subspace projection matrices, thereby recording the essential semantic space of skills. To achieve forget-less and generalization manipulation, we propose a Skills Specialization Aggregation to compute inter-skills similarity in skill semantic subspaces, achieving aggregation of the previously learned skill knowledge for any new or unknown skill. Extensive experiments demonstrate the effectiveness and superiority of our proposed SkillsCrafter.
Figures & tables
Figure 1: The proposed Lifelong Robotic Manipulation task. (a) SkillsCrafter is able to evolve and learn new skills based on learned skills. It maintains a skill knowledge base that stores learned knowledge to allow for efficient learning of new skills using shared knowledge of old skills, and for performing any unknown skill in the open world using previously learned knowledge. (b) Skills catastrophic forgetting under lifelong learning settings. (c) Our SkillsCrafter has a better anti-forgetting performance.
Figure 2: Illustration of the three sets of observation. (a) Subspaces Consistency: The semantic space can be used to associate with the parameter subspace. (b) Different Layers across Various Skills: The importance of different layers is not the same for different skills. (c) Knowledge Decoupled: A tends to learn shared knowledge, while B to learn specific knowledge, naturally.
Figure 3: Illustration of the proposed SkillsCrafter pipeline. It includes (a) a Manipulation Skills Adaptation to achieve retaining the old skills knowledge while inheriting the shared knowledge between new and old skills to facilitate learning of new skills; (b) a Skills Specialization Aggregation to compute inter-skills similarity in skill-specific subspaces to achieve adaptive aggregation of skills knowledge; (c) a Skills Specified Inference to loads aggregated knowledge to achieve any skill manipulation inference.
Figure 4: Illustration of the experiment robotic skill tasks setting. We establish a total of 12 robotic simulator skills and 6 real-environment robotic skills for incremental learning.
Methods
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
Seq-FT (sequence fine-tune all)
0
0
0
0
0
0
0
0
0
0
0
0
12
4
4
80
8
8
6.4
LwF-LoRA ( Li and Hoiem 2017 )
0
4
0
4
0
4
0
0
0
0
0
0
8
12
0
84
4
0
6.7
EWC-LoRA ( Xiang et al. 2023 )
0
0
0
0
4
0
0
0
0
0
0
0
16
8
4
80
8
4
6.9
Dense MoLE ( Chen et al. 2024 )
4
24
4
12
8
8
8
0
4
0
0
8
24
20
28
80
8
8
13.8
Sparse MoLE ( Dou et al. 2024 )
16
32
8
8
12
4
8
4
4
8
0
4
28
16
24
76
4
4
14.4
MoLA ( Gao et al. 2024 )
12
20
12
8
16
8
12
4
0
4
4
12
44
24
24
80
0
8
16.2
Table 1: Test results (Skill-Wise Average Success Rate, ASR ↑ , %) of comparison experiment with LLCRM settings.
Methods
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
Seq-FT
100
100
100
100
100
100
100
100
100
100
100
100
88
96
95
5
85
88
92.0
LwF-LoRA
100
95
100
95
100
93
100
100
100
100
100
100
92
87
100
0
92
100
91.9
EWC-LoRA
100
100
100
100
93
100
100
100
100
100
100
100
83
91
95
0
85
94
91.2
Dense MoLE
93
71
91
86
86
86
85
100
86
100
100
90
75
78
68
0
85
88
81.5
Sparse MoLE
73
62
82
90
79
93
85
80
86
50
100
95
71
83
73
0
92
94
77.0
MoLA
80
76
73
90
71
86
77
80
100
75
75
85
54
74
73
0
100
88
75.4
Table 2: Test results (Skill-Wise Forgetting Rate, FR ↓ , %) of comparison experiment with LLCRM settings.
Figure 5: Illustration for some visualization examples.
Methods
GGM
SOT
INA
ASR %
FR %
Baseline
✗
✗
✗
5.8
92.8
SkillsCrafter w/o GGM
✗
✓
✓
46.9
26.5
SkillsCrafter w/o INA
✓
✓
✗
48.2
23.9
SkillsCrafter w/o SOT
✓
✗
✓
49.1
22.9
SkillsCrafter
✓
✓
✓
52.0
16.0
Table 3: Ablation study for skills shared/special knowledge.
Methods
IM
VM
AVG
TOP
ASR (%) ↑
FR (%)
SkillsCrafter w/ TOP
✗
✗
✗
✓
50.4
16.5
SkillsCrafter w/ Avg
✗
✗
✓
✗
44.4
26.3
SkillsCrafter w/ VM
✗
✓
✗
✗
48.9
20.2
SkillsCrafter
✓
✗
✗
✗
52.0
16.0
Table 4: Ablation study on skill knowledge aggregation.
Notations
Definitions
I
user language instruction
O
vision observation
V(O)
CLIP vision-encoder
S
multi-skills sequence set
{S1,S2,...,St−1}
old skills
St
current skill
Table 5: Some important notations and definitions.
Hyperparameters Name
Value
image size
128 × 128 × 3
per device train batch size B
16
learning rate
0.0001
num train epochs
4
computational bits
16
eval max steps
150
Table 6: Hyper-parameters used in SkillsCrafter.
No.
Skill in Simulator
Instruction Examples
1
open-drawer
“open the top drawer”, “open the middle drawer”, “open the bottom drawer”
2
slide-block
“slide the block to target”
3
put-money
“put the money away in the safe on the top shelf”, “put the money away in the safe on the bottom shelf”
4
sweep-dustpan
“sweep dirt to dustpan”
5
push-buttons
“push the maroon button”, “push the maroon button, then push the blue button”, “push the purple button”
6
turn-tap
“turn right tap”, “turn left tap”
Table 7: Details of Simulator & Real-world Manipulation Skills
Methods
GGM
SOT
INA
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
Baseline
✗
✗
✗
0
0
0
0
0
0
0
0
0
0
0
0
12
4
4
80
4
0
5.8
SkillsCrafter w/o GGM
✗
✓
✓
48
76
32
48
48
48
40
4
12
8
12
68
92
76
72
76
40
44
46.9
SkillsCrafter w/o INA
✓
✓
✗
52
72
28
52
52
48
44
12
12
12
8
72
84
80
80
84
32
44
48.2
SkillsCrafter w/o SOT
✓
✗
✓
56
80
40
60
52
44
48
8
16
8
8
68
84
80
72
76
36
48
49.1
SkillsCrafter
✓
✓
✓
56
80
36
64
48
52
44
12
20
12
12
72
92
84
80
80
40
52
52.0
Table 8: Ablation study for skills shared/special knowledge with ASR %.
Methods
GGM
SOT
INA
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
Baseline
✗
✗
✗
100
100
100
100
100
100
100
100
100
100
100
100
88
96
95
0
92
100
92.8
SkillsCrafter w/o GGM
✗
✓
✓
20
10
27
43
14
14
23
80
57
50
25
15
4
17
18
0
23
35
26.5
SkillsCrafter w/o INA
✓
✓
✗
13
14
36
38
7
14
15
40
57
25
50
0
13
13
9
0
38
35
23.9
SkillsCrafter w/o SOT
✓
✗
✓
7
5
9
29
7
21
8
60
43
50
50
15
13
13
18
5
31
29
22.9
SkillsCrafter
✓
✓
✓
7
5
18
24
14
7
15
40
29
25
25
10
4
9
9
0
23
24
16.0
Table 9: Ablation study for skills shared/special knowledge with FR %.
Methods
IM
VM
Avg
TOP
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
SkillsCrafter w/ TOP
✗
✗
✗
✓
60
80
44
76
56
52
48
16
24
12
16
72
92
88
80
80
4
8
50.4
SkillsCrafter w/ Avg
✗
✗
✓
✗
60
80
40
64
44
48
44
12
16
8
16
68
88
40
84
72
8
8
44.4
SkillsCrafter w VM
✗
✓
✗
✗
52
76
32
60
44
52
48
16
24
12
8
76
84
88
84
76
36
12
48.9
SkillsCrafter
✓
✗
✗
✗
56
80
36
64
48
52
44
12
20
12
12
72
92
84
80
80
40
52
52.0
Table 10: Ablation study for skills Knowledge aggregation with ASR %.
Methods
IM
VM
Avg
TOP
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
S17
S18
Avg.
SkillsCrafter w/ TOP
✗
✗
✗
✓
0
5
0
10
0
7
8
20
14
25
0
10
4
4
9
0
92
88
16.5
SkillsCrafter w/ Avg
✗
✗
✓
✗
0
5
9
24
21
14
15
40
43
50
0
15
8
57
5
-5
85
88
26.3
SkillsCrafter w VM
✗
✓
✗
✗
13
10
27
29
21
7
8
20
14
25
50
5
13
4
5
0
31
82
20.2
SkillsCrafter
✓
✗
✗
✗
7
5
18
24
14
7
15
40
29
25
25
10
4
9
9
0
23
24
16.0
Table 11: Ablation study for skills Knowledge aggregation with FR %.
Figure 6: A photograph of the proposed UR5 robotic system.
Figure 7: Illustration of the proposed UR5 robotic system.