The Motion-Overlap Scheme for Reducing the Time between Continuous Scans of Wafer Stage for Step-and-Scan Lithography

2011 ◽  
Vol 121-126 ◽  
pp. 110-115
Author(s):  
Hai Hong Pan ◽  
Lin Chen ◽  
Yun Fei Zhou
Keyword(s):  
Motion Planning ◽  
Production Efficiency ◽  
Planning Method ◽  
Continuous Exposure ◽  
Theoretical Derivation ◽  
Scanning Direction ◽  
Exposure Field ◽  
Simulation Results ◽  
Transitional Time ◽  
Exposure Process

During the exposure process of a step-and-scan lithography, the transitional time between continuous scans does not produce production efficiency in which no scanning occurs. To minimize the transitional time and therefore to improve the productivity we introduce the motion-overlap scheme, which inserts a step-move between the overrun phase and the phase before exposure of next field along the scanning direction for wafer stage during the continuous exposure process. The simulation results show that the motion-overlap scheme enables the total time of two continuous scans of four different exposure field sizes reduce 8.28%, 7.11%, 5.87% and 4.53%, respectively, compared with the conventional motion planning method. This indicates that the theoretical derivation of motion-overlap planning method is effective.

Motion Planning Method for Two Stacker Cranes in an Automated Storage and Retrieval System

2012 ◽  
Vol 6 (6) ◽  
pp. 792-801 ◽  
Author(s):  
Hisato Hino ◽  
◽  
Yoshimasa Kobayashi ◽  
Toshimitsu Higashi ◽  
Jun Ota ◽  
...  
Keyword(s):  
Motion Planning ◽  
Retrieval System ◽  
Vertical Direction ◽  
Binary Search ◽  
Planning Method ◽  
Storage And Retrieval ◽  
Standard Task ◽  
Simulation Results ◽  
Automated Storage ◽  
Task Conditions

In this paper, a motion planning method for two stacker cranes in an Automated Storage and Retrieval System (AS/RS) is proposed. For the cranes to operate cooperatively, they must perform tasks while avoiding collisions. In addition, the requirements, which include fast operation and short calculation time, must be satisfied, along with a specific mechanical constraint on the motion of the stacker cranes. For these problems, an approach is proposed in which a motion is generated on two levels. On the first, collision is avoided by using constraint on trajectories. A trajectory generated on this level ensures the shortest travel time. If a collision cannot be avoided on the first level, the system shifts to the second, in which heuristics are used for collision avoidance. The proposal is for highspeed heuristics based on a binary search. The effectiveness of the proposed algorithm is shown through simulations. The simulation results indicate that, in a layout of 60 racks in the horizontal direction and 10 in the vertical direction under standard task conditions, the method has an efficiency of 1.91 with respect to a single crane system and 1.66 seconds for the motion planning of one task when a computer with a 3.0 GHz CPU is used.

scholarly journals Motion Planning for Mobile Robot with Modified BIT* and MPC

2021 ◽  
Vol 11 (1) ◽  
pp. 426
Author(s):  
Puyong Xu ◽  
Ning Wang ◽  
Shi-Lu Dai ◽  
Lei Zuo
Keyword(s):  
Model Predictive Control ◽  
Mobile Robot ◽  
Motion Planning ◽  
Objective Function ◽  
Free Path ◽  
Predictive Control ◽  
Planning Method ◽  
Robot Motion ◽  
Robot Motion Planning ◽  
Simulation Results

In this paper, a mobile robot motion planning method with modified BIT* (batch informed trees) and MPC (Model Predictive Control) is presented. The conventional BIT* was modified here by integrating a stretch method that improves the path points connections, to get a collision-free path more quickly. After getting a reference path, the MPC method is employed to determine the motion at each moment with a given objective function. In the objective function, a repulsive function based on the direction and distance of the obstacles is introduced to avoid the robot being too close to the obstacle, so the safety can be ensured. Simulation results show the good navigation performance of the whole framework in different scenarios.

Iterative Transportation by Multiple Mobile Robots Considering Unknown Obstacles

2009 ◽  
Vol 21 (1) ◽  
pp. 44-56
Author(s):  
Kousuke Inoue ◽  
◽  
Jun Ota ◽  
Tamio Arai ◽  
Keyword(s):  
Reinforcement Learning ◽  
Motion Planning ◽  
Mobile Robots ◽  
Efficient Method ◽  
Planning Method ◽  
Configuration Spaces ◽  
Path Generation ◽  
Final Phase ◽  
Simulation Results ◽  
Environmental Exploration

The focus in this paper is on a planning method for an iterative transportation task performed by mobile robots in environments including unknown obstacles. This task requires the acquisition of environmental information, the generation of the appropriate path network based on the acquired information, and the formation of a group of robots on the planned path network. To achieve an efficient method of transportation, a motion planning architecture is proposed that includes three phases, i.e., environmental exploration, path generation, and learning of formation. In the first phase, robots cooperatively explore the environment using a learned visibility graph while transporting. Next, a network of transportation paths consisting of 1- and 2-lane paths is generated using two kinds of configuration spaces. In the final phase, every robot learns a behavior strategy by reinforcement learning to acquire an efficient formation of transportation. The simulation results indicate the effectiveness of the proposed architecture.

Autonomous Motion Planning in Pedestrian Space Considering Passenger Comfort

2020 ◽  
Vol 32 (3) ◽  
pp. 580-587
Author(s):  
Hiroshi Yoshitake ◽  
◽  
Kenta Nishi ◽  
Motoki Shino
Keyword(s):  
Numerical Simulation ◽  
Motion Planning ◽  
Elderly People ◽  
Planning Method ◽  
Passenger Comfort ◽  
Autonomous Motion ◽  
Simulation Results ◽  
Pedestrian Space

In this study, we proposed an autonomous motion planning method for improving passenger comfort while ensuring safety, particularly with respect to mobility scooters used by elderly people. We proposed a trajectory planner for restricting vehicle behaviors with large accelerations and jerks by selecting a safe trajectory from a set of preset trajectories. Then, based on this trajectory planner, we developed an autonomous motion planning method with four different driving modes, and evaluated the effectiveness of the method through a numerical simulation. The simulation results demonstrated that the proposed method increased comfort without compromising on safety.

Speed regulation control of tractors’ new dual-flow transmission system based on slip rate resistance classification

2021 ◽  
pp. 095440702110105
Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Production Efficiency ◽  
Sliding Mode ◽  
Slip Rate ◽  
Speed Control ◽  
Working Environment ◽  
Vehicle Speed ◽  
Speed Change ◽  
Simulation Results

Fluctuations in operation resistance during the operating process lead to reduced efficiency in tractor production. To address this problem, the project team independently developed and designed a new type of hydraulic mechanical continuously variable transmission (HMCVT). Based on introducing the mechanical structure and transmission principle of the HMCVT system, the priority of slip rate control and vehicle speed control is determined by classifying the slip rate. In the process of vehicle speed control, the driving mode of HMCVT system suitable for the current resistance state is determined by classifying the operation resistance. The speed change rule under HMT and HST modes is formulated with the goal of the highest production efficiency, and the displacement ratio adjustment surfaces under HMT and HST modes are determined. A sliding mode control algorithm based on feedforward compensation is proposed to address the problem that the oil pressure fluctuation has influences on the adjustment accuracy of hydraulic pump displacement. The simulation results of Simulink show that this algorithm can not only accurately follow the expected signal changes, but has better tracking stability than traditional PID control algorithm. The HMCVT system and speed control strategy models were built, and simulation results show that the speed control strategy can restrict the slip rate of driving wheels within the allowable range when load or road conditions change. When the tractor speed is lower than the lower limit of the high-efficiency speed range, the speed change law formulated in this paper can improve the tractor speed faster than the traditional rule, and effectively ensure the production efficiency. The research results are of great significance for improving tractor’s adaptability to complex and changeable working environment and promoting agricultural production efficiency.

ADD-RRV for motion planning in complex environments

Robotica ◽  
2021 ◽  
pp. 1-18
Author(s):  
Peng Cai ◽  
Xiaokui Yue ◽  
Hongwen Zhang
Keyword(s):  
Principal Component Analysis ◽  
Motion Planning ◽  
Configuration Space ◽  
Principal Component ◽  
Component Analysis ◽  
Planning Method ◽  
Complex Environments ◽  
Local Configuration ◽  
Narrow Passage

Abstract In this paper, we present a novel sampling-based motion planning method in various complex environments, especially with narrow passages. We use online the results of the planner in the ADD-RRT framework to identify the types of the local configuration space based on the principal component analysis (PCA). The identification result is then used to accelerate the expansion similar to RRV around obstacles and through narrow passages. We also propose a modified bridge test to identify the entrance of a narrow passage and boost samples inside it. We have compared our method with known motion planners in several scenarios through simulations. Our method shows the best performance across all the tested planners in the tested scenarios.

New repetitive motion planning scheme with cube end-effector planning precision for redundant robotic manipulators

Robotica ◽  
2021 ◽  
pp. 1-22
Author(s):  
Limin Shen ◽  
Yuanmei Wen
Keyword(s):  
Theoretical Analysis ◽  
Motion Planning ◽  
Robotic Manipulators ◽  
Robotic Manipulator ◽  
Repetitive Motion ◽  
End Effector ◽  
Difference Formula ◽  
Planning Scheme ◽  
Simulation Results ◽  
The Difference

Abstract Repetitive motion planning (RMP) is important in operating redundant robotic manipulators. In this paper, a new RMP scheme that is based on the pseudoinverse formulation is proposed for redundant robotic manipulators. Such a scheme is derived from the discretization of an existing RMP scheme by utilizing the difference formula. Then, theoretical analysis and results are presented to show the characteristic of the proposed RMP scheme. That is, this scheme possesses the characteristic of cube pattern in the end-effector planning precision. The proposed RMP scheme is further extended and studied for redundant robotic manipulators under joint constraint. Based on a four-link robotic manipulator, simulation results substantiate the effectiveness and superiority of the proposed RMP scheme and its extended one.

Research on autonomous exploration motion planning method of mobile robots for unstructured scenarios

2021 ◽  
Author(s):  
Xuehao Sun ◽  
Shuchao Deng ◽  
Baohong Tong ◽  
Shuang Wang ◽  
Shuai Ma ◽  
...  
Keyword(s):  
Motion Planning ◽  
Mobile Robots ◽  
Planning Method ◽  
Autonomous Exploration
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