scholarly journals Monotone Temporal Planning: Tractability, Extensions and Applications

2014 ◽  
Vol 50 ◽  
pp. 447-485 ◽  
Author(s):  
M. Cooper ◽  
F. Maris ◽  
P. Régnier
Keyword(s):  
Polynomial Time ◽  
Temporal Information ◽  
Planning Problem ◽  
Temporal Planning ◽  
Concurrent Execution ◽  
Difference Constraints ◽  
Potential Applications ◽  
Polynomially Solvable ◽  
Solvable Class ◽  
Planning Problems

This paper describes a polynomially-solvable class of temporal planning problems. Polynomiality follows from two assumptions. Firstly, by supposing that each sub-goal fluent can be established by at most one action, we can quickly determine which actions are necessary in any plan. Secondly, the monotonicity of sub-goal fluents allows us to express planning as an instance of STP≠ (Simple Temporal Problem with difference constraints). This class includes temporally-expressive problems requiring the concurrent execution of actions, with potential applications in the chemical, pharmaceutical and construction industries. We also show that any (temporal) planning problem has a monotone relaxation which can lead to the polynomial-time detection of its unsolvability in certain cases. Indeed we show that our relaxation is orthogonal to relaxations based on the ignore-deletes approach used in classical planning since it preserves deletes and can also exploit temporal information.

Operational Planning Using Mixed Integer Programming

1988 ◽  
Vol 64 (6) ◽  
pp. 485-488 ◽  
Author(s):  
H. Douglas Walker ◽  
Stephen W. Preiss
Keyword(s):  
Planning Process ◽  
Cost Savings ◽  
Mathematical Structure ◽  
Timber Harvesting ◽  
Operational Planning ◽  
Mixed Integer ◽  
Forest Planning ◽  
Planning Problem ◽  
Process Data ◽  
Planning Problems

A mathematical model was constructed and used to help plan five-year timber harvesting and delivery activities from an industrially managed public forest in Ontario. Harvest systems, harvest levels, and wood flows from compartments within the forest to various mills and delivery points were scheduled to minimize costs. The mathematical structure of the model may suggest applications to related forest planning problems. The model was useful in addressing the planning problem, and model results were used within the company's planning process. Data accuracy problems precluded assessing definitively the expected cost savings resulting from model use.

A direct approach to solving trajectory planning problems using genetic algorithms with dynamics considerations in complex environments

Robotica ◽  
2014 ◽  
Vol 33 (3) ◽  
pp. 669-683 ◽  
Author(s):  
Fares J. Abu-Dakka ◽  
Francisco J. Valero ◽  
Jose Luis Suñer ◽  
Vicente Mata
Keyword(s):  
Trajectory Planning ◽  
Direct Method ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Computational Time ◽  
Planning Problem ◽  
Complex Environments ◽  
Operational Parameters ◽  
Algorithm Efficiency ◽  
Planning Problems

SUMMARYThis paper presents a new genetic algorithm methodology to solve the trajectory planning problem. This methodology can obtain smooth trajectories for industrial robots in complex environments using a direct method. The algorithm simultaneously creates a collision-free trajectory between initial and final configurations as the robot moves. The presented method deals with the uncertainties associated with the unknown kinematic properties of intermediate via points since they are generated as the algorithm evolves looking for the solution. Additionally, the objective of this algorithm is to minimize the trajectory time, which guides the robot motion. The method has been applied successfully to the PUMA 560 robotic system. Four operational parameters (execution time, computational time, end-effector distance traveled, and significant points distance traveled) have been computed to study and analyze the algorithm efficiency. The experimental results show that the proposed optimization algorithm for the trajectory planning problem of an industrial robot is feasible.

scholarly journals A comprehensive approach for managing feasible solutions in production planning by an interacting network of Zero-Suppressed Binary Decision Diagrams

2015 ◽  
Vol 2 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Keita Takahashi ◽  
Masahiko Onosato ◽  
Fumiki Tanaka
Keyword(s):  
Production Planning ◽  
Production Scheduling ◽  
Binary Decision Diagrams ◽  
Solution Space ◽  
Product Lifecycle Management ◽  
Planning Problem ◽  
Decision Diagrams ◽  
Binary Decision ◽  
Feasible Solutions ◽  
Planning Problems

Abstract Product Lifecycle Management (PLM) ranges from design concepts of products to disposal. In this paper, we focus on the production planning phase in PLM, which is related to process planning and production scheduling and so on. In this study, key decisions for the creation of production plans are defined as production-planning attributes. Production-planning attributes correlate complexly in production-planning problems. Traditionally, the production-planning problem splits sub-problems based on experiences, because of the complexity. In addition, the orders in which to solve each sub-problem are determined by priorities between sub-problems. However, such approaches make solution space over-restricted and make it difficult to find a better solution. We have proposed a representation of combinations of alternatives in production-planning attributes by using Zero-Suppressed Binary Decision Diagrams. The ZDD represents only feasible combinations of alternatives that satisfy constraints in the production planning. Moreover, we have developed a solution search method that solves production-planning problems with ZDDs. In this paper, we propose an approach for managing solution candidates by ZDDs' network for addressing larger production-planning problems. The network can be created by linkages of ZDDs that express constraints in individual sub-problems and between sub-problems. The benefit of this approach is that it represents solution space, satisfying whole constraints in the production planning. This case study shows that the validity of the proposed approach.

scholarly journals USEFULNESS OF THE CONSTRAINED PLANNING PROBLEM IN A MODEL OF MONEY

2008 ◽  
Vol 12 (4) ◽  
pp. 503-525 ◽  
Author(s):  
Joydeep Bhattacharya ◽  
Rajesh Singh
Keyword(s):  
Government Policy ◽  
Optimal Policy ◽  
Policy Choice ◽  
Planning Problem ◽  
Equilibrium Concept ◽  
Limited Communication ◽  
Monetary Economy ◽  
Optimal Policies ◽  
Set Up ◽  
Planning Problems

In this paper, we study a decentralized monetary economy with a specified set of markets, rules of trade, an equilibrium concept, and a restricted set of policies and derive a set of equilibrium (monetary) allocations generated by these policies. Next we set up a simpler constrained planning problem in which we restrict the planner to choose from a set that contains the set of equilibrium allocations in the decentralized economy. If there is a government policy that allows the decentralized economy to achieve the constrained planner's allocation, then it is the optimal policy choice. To illustrate the power of such analyses, we solve such planning problems in three monetary environments with limited communication. The upshot is that solving constrained planning problems is potentially an extremely “efficient” (easy and quick) way of deriving optimal policies for the corresponding decentralized economies.

Parameter self-adaptation in biped navigation employing nonuniform randomized footstep planner

Robotica ◽  
2010 ◽  
Vol 28 (6) ◽  
pp. 929-936 ◽  
Author(s):  
Zeyang Xia ◽  
Jing Xiong ◽  
Ken Chen
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Back Propagation ◽  
Planning Problem ◽  
Navigation Problem ◽  
Probability Threshold ◽  
Self Adaptation ◽  
The Relationship ◽  
Planning Problems ◽  
Key Parameter

SUMMARYIn our previous work, a random-sampling-based footstep planner has been proposed for global biped navigation. Goal-probability threshold (GPT) is the key parameter that controls the convergence rate of the goal-biased nonuniform sampling in the planner. In this paper, an approach to optimized GPT adaptation is explained by a benchmarking planning problem. We first construct a benchmarking model, in which the biped navigation problem is described in selected parameters, to study the relationship between these parameters and the optimized GPT. Then, a back-propagation (BP) neural network is employed to fit this relationship. With a trained BP neural network modular, the optimized GPT can be automatically generated according to the specifications of a planning problem. Compared with previous methods of manual and empirical tuning of GPT for individual planning problems, the proposed approach is self-adaptive. Numerical experiments verified the performance of the proposed approach and furthermore showed that planning with BP-generated GPTs is more stable. Besides the implementation in specific parameterized environments studied in this paper, we attempt to provide the frame of the proposed approach as a reference for footstep planning in other environments.

scholarly journals Multiquery Motion Planning in Uncertain Spaces: Incremental Adaptive Randomized Roadmaps

2019 ◽  
Vol 29 (4) ◽  
pp. 641-654
Author(s):  
Weria Khaksar ◽  
Md Zia Uddin ◽  
Jim Torresen
Keyword(s):  
Motion Planning ◽  
Minimum Distance ◽  
Planning Problem ◽  
Grid Structure ◽  
Discrete Time System ◽  
Environment Map ◽  
Sample Classification ◽  
Adjustment Strategy ◽  
Hybrid Sample ◽  
Planning Problems

Abstract Sampling-based motion planning is a powerful tool in solving the motion planning problem for a variety of different robotic platforms. As its application domains grow, more complicated planning problems arise that challenge the functionality of these planners. One of the main challenges in the implementation of a sampling-based planner is its weak performance when reacting to uncertainty in robot motion, obstacles motion, and sensing noise. In this paper, a multi-query sampling-based planner is presented based on the optimal probabilistic roadmaps algorithm that employs a hybrid sample classification and graph adjustment strategy to handle diverse types of planning uncertainty such as sensing noise, unknown static and dynamic obstacles and an inaccurate environment map in a discrete-time system. The proposed method starts by storing the collision-free generated samples in a matrix-grid structure. Using the resulting grid structure makes it computationally cheap to search and find samples in a specific region. As soon as the robot senses an obstacle during the execution of the initial plan, the occupied grid cells are detected, relevant samples are selected, and in-collision vertices are removed within the vision range of the robot. Furthermore, a second layer of nodes connected to the current direct neighbors are checked against collision, which gives the planner more time to react to uncertainty before getting too close to an obstacle. The simulation results for problems with various sources of uncertainty show a significant improvement compared with similar algorithms in terms of the failure rate, the processing time and the minimum distance from obstacles. The planner is also successfully implemented and tested on a TurtleBot in four different scenarios with uncertainty.

scholarly journals Generalized Contraflow for Evacuation Planning Problem

2018 ◽  
Vol 1 (1) ◽  
pp. 38-49
Author(s):  
Urmila Pyakurel
Keyword(s):  
Polynomial Time ◽  
World Wide ◽  
Approximation Scheme ◽  
Evacuation Planning ◽  
Planning Problem ◽  
Polynomial Time Approximation Scheme ◽  
Lossy Networks ◽  
Approximation Solution ◽  
Time Approximation ◽  
Pseudo Polynomial Time

The research in evacuation planning has been very much motivated due to the rapidly increased number of disasters world wide. It supports to remove the evacuees from dangerous areas to safe areas. Contraflow reconfiguration during evacuation make traffic smooth by reversing the required road directions from dangerous areas to safe areas that improve both flow and speed significantly. On lossy network, the generalized maximum dynamic contraflow and generalized earliest arrival contraflow problems have been solved efficiently with pseudo-polynomial time. This paper focuses in analytical solutions on generalized contraflow for evacuation planning problem. The problems are considered on two terminal lossy networks. We solve the generalized maximum static contraflow problem in pseudo-polynomial time and compute its approximation solution in polynomial time. Moreover, we present a fully polynomial time approximation scheme (FPTAS) to compute an approximate generalized maximum dynamic contraflow solution.

scholarly journals Compilation-Based Approaches to Parallel Planning: An Empirical Comparison

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Kristýna Pantůčková ◽  
Roman Barták
Keyword(s):  
Programming Language ◽  
Constraint Satisfaction ◽  
Constraint Satisfaction Problem ◽  
Automated Planning ◽  
Boolean Satisfiability ◽  
Planning Problem ◽  
Empirical Comparison ◽  
Boolean Satisfiability Problem ◽  
International Planning ◽  
Planning Problems

Automated planning deals with finding a sequence of actions, a plan, to reach a goal. One of the possible approaches to automated planning is a compilation of a planning problem to a Boolean satisfiability problem or to a constraint satisfaction problem, which takes direct advantage of the advancements of satisfiability and constraint satisfaction solvers. This paper provides a comparison of three encodings proposed for the compilation of planning problems: Transition constraints for parallel planning (TCPP), Relaxed relaxed exist-Step encoding and Reinforced Encoding. We implemented the encodings using the programming language Picat 2.8, we suggested certain modifications, and we compared the performance of the encodings on benchmarks from international planning competitions.

scholarly journals Computing Hierarchical Finite State Controllers With Classical Planning

2018 ◽  
Vol 62 ◽  
pp. 755-797 ◽  
Author(s):  
Javier Segovia-Aguas ◽  
Sergio Jiménez ◽  
Anders Jonsson
Keyword(s):  
Planning Problem ◽  
Finite State ◽  
Finite Set ◽  
Planning Problems

Finite State Controllers (FSCs) are an effective way to compactly represent sequential plans. By imposing appropriate conditions on transitions, FSCs can also represent generalized plans (plans that solve a range of planning problems from a given domain). In this paper we introduce the concept of hierarchical FSCs for planning by allowing controllers to call other controllers. This call mechanism allows hierarchical FSCs to represent generalized plans more compactly than individual FSCs, to compute controllers in a modular fashion or even more, to compute recursive controllers. The paper introduces a classical planning compilation for computing hierarchical FSCs that solve challenging generalized planning tasks. The compilation takes as input a finite set of classical planning problems from a given domain. The output of the compilation is a single classical planning problem whose solution induces: (1) a hierarchical FSC and (2), the corresponding validation of that controller on the input classical planning problems.

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