Humanoid robots deployed in industrial environments are required to perform load-carrying transportation tasks that tightly couple locomotion and manipulation. However, achieving stable and robust locomotion under varying payloads and upper-body motions is challenging due to dynamic coupling and partial observability. This paper presents a load-aware locomotion framework for industrial humanoids based on a decoupled yet coordinated loco-manipulation architecture. Lower-body locomotion is controlled via a reinforcement learning policy producing residual joint actions on kinematically derived nominal configurations. A kinematics-based locomotion reference with a height-conditioned joint-space offset guides learning, while a history-based state estimator infers base linear velocity and height and encodes residual load- and manipulation-induced disturbances in a compact latent representation. The framework is trained entirely in simulation and deployed on a full-size humanoid robot without fine-tuning. Simulation and real-world experiments demonstrate faster training, accurate height tracking, and stable loco-manipulation. Project page: https://lequn-f.github.io/LALO/
Figures & tables
Category
Dimension
Noise Scale
Phase Input
2
0
Projected gravity
3
±0.05
Angular velocity
3
±0.1
Joint positions
27
±0.02
Joint velocities
27
±0.5
Command
4
0
TABLE I: Observation space of the locomotion policy.
Fig. 1: Overview of the proposed load-aware humanoid loco-manipulation framework. Upper-body manipulation is generated by perception-driven kinematic control using 6D object pose estimation, while lower-body locomotion is governed by a residual reinforcement learning policy with height-conditioned offsets and history-based state estimation. Historical proprioceptive observations are encoded by a history-based state estimator to infer base velocity, base height, and a compact latent state capturing load- and manipulation-induced disturbances.
Reward term
Formulation
Weight (μi)
Linear velocity tracking
exp(−4∥[vx,vy]−[vx∗,vy∗]∥2)
1.2
Angular velocity tracking
exp(−4(ωz−ωz∗)2)
1.1
Base height tracking
exp(−50∣hb,rel−hb,rel∗∣)
2.0
Low-speed consistency
rls(vx,vx∗)⋅I(∣vx∗∣>0.1)
0.2
Orientation stabilization
exp(−10∥gproj,xy∥)
1.0
Velocity mismatch
0.5(exp(−10vz2)+exp(−5∥ωx,y∥))
0.5
TABLE II: Reward terms and weights used for training.
Parameter
Unit
Range
Operator
Ground Friction
–
[0.1, 3.0]
–
Restitution Coefficient
–
[0.0, 1]
–
External Push Velocity (XY)
m/s
[-0.5, 0.5]
additive
External Push Angular Velocity
rad/s
[0, 0.6]
additive
Base Mass Offset
kg
[-5.0, 10.0]
additive
Hand Mass Offset
kg
[-0.1, 0.3]
additive
TABLE III: Overview of Domain Randomization
Fig. 2: Multi-box detection and target 6D pose estimation. Blue boxes denote instances detected by YOLO-seg, the red box indicates the selected target, and the green wireframe shows the 6D pose estimated by FoundationPose.
Parameter Name
Value
Value loss coefficient
1.0
Number of Epochs
5
Clipping
0.2
Entropy Coefficient
0.003
Discount Factor
0.99
GAE Discount Factor
0.95
TABLE IV: PPO Training Hyperparameters
Fig. 3: Training convergence comparison of different offset and reference formulations. (a) Episode reward for tracking base height versus environment steps. (b) Mean episode length versus environment steps.
Fig. 4: Distribution of joint residual actions during steady-state walking.
Fig. 5: Prediction performance of the history-based state estimator. Comparison between commanded, ground-truth, and estimated states for (a) base velocity vx , (b) base velocity vy , and (c) base height. The estimator achieves low mean squared error under dynamic motion conditions.
Fig. 6: Real-world loco-manipulation experiments in an industrial box transportation scenario. (a–c) Box transportation without depalletizing: the robot transitions from unloaded walking to load-carrying locomotion, squats to a target height, places the box onto a rack while maintaining a crouched posture, and then stands up. (d–f) Transportation with depalletizing: the robot performs box depalletizing, walks while carrying a 5 kg payload, places the box at the designated location, and continues unloaded walking for the next task. The environment is a one-to-one reconstruction of an industrial factory setting and corresponds to the task scenario of the World Humanoid Robot Games.