359 research outputs found
SDF-Pack: Towards Compact Bin Packing with Signed-Distance-Field Minimization
Robotic bin packing is very challenging, especially when considering
practical needs such as object variety and packing compactness. This paper
presents SDF-Pack, a new approach based on signed distance field (SDF) to model
the geometric condition of objects in a container and compute the object
placement locations and packing orders for achieving a more compact bin
packing. Our method adopts a truncated SDF representation to localize the
computation, and based on it, we formulate the SDF minimization heuristic to
find optimized placements to compactly pack objects with the existing ones. To
further improve space utilization, if the packing sequence is controllable, our
method can suggest which object to be packed next. Experimental results on a
large variety of everyday objects show that our method can consistently achieve
higher packing compactness over 1,000 packing cases, enabling us to pack more
objects into the container, compared with the existing heuristics under various
packing settings
A hybrid algorithm for the vehicle routing problem with three-dimensional loading constraints and mixed backhauls
In this paper, a variant of the vehicle routing problem with mixed backhauls (VRPMB) is presented, i.e. goods have to be delivered from a central depot to linehaul customers, and, at the same time, goods have to be picked up from backhaul customers and brought to the depot. Both types of customers can be visited in mixed sequences. The goods to be delivered or picked up are three-dimensional (cuboid) items. Hence, in addition to a routing plan, a feasible packing plan for each tour has to be provided considering a number of loading constraints. The resulting problem is the vehicle routing problem with three-dimensional loading constraints and mixed backhauls (3L-VRPMB)
Heuristics approaches for three-dimensional strip packing and multiple carrier transportation plans
In transport logistic operations, an efficient delivery plan and better utilisation of vehicles will result in fuel cost savings, reduced working hours and even reduction of carbon dioxide emissions. This thesis proposes various algorithmic approaches to generate improved performance in automated vehicle load packing and route planning. First, modifications to best-fit heuristic methodologies are proposed and then incorporated into a simple but effective “look-ahead” heuristic procedure. The results obtained are very competitive and in some cases best-known results are found for different sets of constraints on three-dimensional strip packing problems. Secondly, a review and comparison of different clustering techniques in transport route planning is presented. This study shows that the algorithmic approach performs according to the specific type of real-world transport route planning scenario under consideration. This study helps to achieve a better understanding of how to conduct the automated generation of vehicle routes that meet the specific conditions required in the operations of a transport logistics company. Finally, a new approach to measuring the quality of transportation route plans is presented showing how this procedure has a positive effect on the quality of the generated route plans. In summary, this thesis proposes new tailored and effective heuristic methodologies that have been tested and incorporated into the real-world operations of a transport logistics company. The research work presented here is a modest yet significant advance to better understanding and solving the difficult problems of vehicle loading and routing in real-world scenarios
Online 3D Bin Packing with Constrained Deep Reinforcement Learning
We solve a challenging yet practically useful variant of 3D Bin Packing
Problem (3D-BPP). In our problem, the agent has limited information about the
items to be packed into the bin, and an item must be packed immediately after
its arrival without buffering or readjusting. The item's placement also
subjects to the constraints of collision avoidance and physical stability. We
formulate this online 3D-BPP as a constrained Markov decision process. To solve
the problem, we propose an effective and easy-to-implement constrained deep
reinforcement learning (DRL) method under the actor-critic framework. In
particular, we introduce a feasibility predictor to predict the feasibility
mask for the placement actions and use it to modulate the action probabilities
output by the actor during training. Such supervisions and transformations to
DRL facilitate the agent to learn feasible policies efficiently. Our method can
also be generalized e.g., with the ability to handle lookahead or items with
different orientations. We have conducted extensive evaluation showing that the
learned policy significantly outperforms the state-of-the-art methods. A user
study suggests that our method attains a human-level performance
Volumetric Techniques for Product Routing and Loading Optimisation in Industry 4.0: A Review
Industry 4.0 has become a crucial part in the majority of processes, components, and related modelling, as well as predictive tools that allow a more efficient, automated and sustainable approach to industry. The availability of large quantities of data, and the advances in IoT, AI, and data-driven frameworks, have led to an enhanced data gathering, assessment, and extraction of actionable information, resulting in a better decision-making process. Product picking and its subsequent packing is an important area, and has drawn increasing attention for the research community. However, depending of the context, some of the related approaches tend to be either highly mathematical, or applied to a specific context. This article aims to provide a survey on the main methods, techniques, and frameworks relevant to product packing and to highlight the main properties and features that should be further investigated to ensure a more efficient and optimised approach
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