Jeffrey Dahl

A general framework for automatic CAD-guided tool planning for surface manufacturing

Surface manufacturing is widely used in industry. Automatic CAD-guided tool planning has many applications in surface manufacturing, such as spray painting, spray forming, rapid tooling, cleaning and polishing. According to the material quantity requirements, these tasks can be categorized into two groups: the material uniformity problem and coverage problem. A general framework is developed to automatically generate trajectories of a free-form surface for these tasks. A given task is first transformed into one of the groups. Based on the CAD model of a free-form surface, constraints and tool model, a trajectory for a free-form surface is generated. Velocity optimization is discussed to optimize the material quantity. Simulations are performed to verify the developed framework. This framework can also be extended to other applications.

CAD-GUIDED SPRAY GUN TRAJECTORY PLANNING OF FREE-FORM SURFACES IN MANUFACTURING

Automatic trajectory generation for spray painting is highly desirable for todays automotive manufacturing. Generating paint gun trajectories for free-form surfaces to satisfy paint thickness requirements is still highly challenging due to the complex geometry of free-form surfaces. In this paper, a CAD-guided paint gun trajectory generation system for free-form surfaces has been developed. The system utilizes the CAD information of a free-form surface to be painted and a paint gun model to generate a paint gun trajectory to satisfy the paint thickness requirements. The paint thickness deviation from the required paint thickness is optimized by modifying the paint gun velocity. A paint thickness verication method is also provided to verify the generated trajectories. The results of simulations have shown that the trajectory generation system achieves satisfactory performance. This trajectory generation system can also be applied to generate trajectories for many other CAD-guided robot trajectory planning...

Optimal spray gun trajectory planning with variational distribution for forming process

Automated chopper gun trajectory planning for spray forming is highly desirable for todays automotive manufacturing. Generating chopper gun trajectories for free-form surfaces to satisfy thickness requirements is still highly challenging due to the complexity of problems. Automated trajectory planning for constant material distribution has been widely studied. However, achieving a variational (non-uniform) material distribution has not been addressed. A CAD-guided chopper gun trajectory planning system with non-uniform material distribution for free-form surfaces is presented. A multi-objective constrained optimization problem is formulated. The simulation results have shown that this system achieves performance required by production applications. This trajectory planning algorithm can also be applied to generate trajectories for other CAD-guided robot trajectory planning applications.

Optimizing material distribution for tool trajectory generation in surface manufacturing

Surface manufacturing is widely used in industry. Automatic CAD-guided tool planning has many applications in surface manufacturing, such as spray painting, spray forming and indirect rapid tooling. Generating tool trajectories for freeform surfaces to satisfy the given requirements is still highly challenging due to the complex geometry of free-form surfaces and the spray gun model. A CAD-guided tool trajectory generation system for free-form surfaces has been developed in our previous work. A material distribution model is also presented. Because of the irregular shape of automotive parts, the spray width may not be a constant. Also the path integration for a part with multiple patches may need the spray width to be changed. This will increase the material distribution deviation. In this paper, algorithms are developed to minimize the material distribution deviation because of the change of the spray width. The material distribution requirements can then be satisfied

Development of automated chopper gun trajectory planning for spray forming

Automated chopper gun trajectory planning (CGTP) for spray forming is highly desirable for todays automotive manufacturing. Generating chopper gun trajectories for free‐form surfaces to satisfy material distribution requirements is still highly challenging due to the complexity of the problems. In this paper, a user‐friendly software for automated CGTP has been developed. The CGTP software can take different formats of the CAD models of parts. A chopper gun trajectory is generated based on the CAD model of a part, chopper gun model, and constraints. A part is partitioned into patches to satisfy the given constraints. A trajectory integration algorithm is developed to integrate the trajectories of the patches to form a trajectory for the part. The CGTP software has been tested by Ford Motor Company and achieved satisfactory results.

Robot trajectory integration for painting automotive parts with multiple patches

Automatic trajectory generation for spray painting is highly desirable for todays automotive manufacturing. Generating a trajectory for a surface with only one patch is widely studied to satisfy the paint thickness constraints. However, a complex surface has to be divided into several patches to satisfy the paint thickness and paint gun orientation constraints. Trajectory generation for a surface with multiple patches has not been addressed yet. In this paper, optimization processes are developed to optimize the paint thickness on a surface which consists of several patches. Optimization results are presented. Simulations are performed to verify the optimized parameters. Verification results is consistent with the optimization results.

Analysis of system performance for robotic spray forming process

Automatic chopper gun trajectory generation for spray forming is highly desirable for todays automotive manufacturing. Generating chopper gun trajectories for free-form surfaces to satisfy the given requirements is still highly challenging due to the complex geometry of free-form surfaces and the spray gun model. A CAD-guided chopper gun trajectory generation system for both uniform and nonuniform material distribution of free-form surfaces has been developed in our previous work. A material distribution model is also presented. To verify the developed algorithms, experiments were performed. In this paper, the experimental results are presented and compared with the simulation results. The results demonstrate that the developed trajectory generation system can be applied to generate trajectories for free-form surfaces such that the material distribution requirements can be satisfied. Also, the material distribution model can be used to compute the material distribution for free-form surfaces. This trajectory generation method can also be applied to generate trajectories for many other CAD-guided robot trajectory planning applications.

Chopper Gun Trajectory Optimization for Spray Forming in Automotive Manufacturing

Automatic chopper gun trajectory generation for spray forming is highly desirable for today’s automotive manufacturing. Generating chopper gun trajectories for free‐form surfaces to satisfy thickness requirements is still highly challenging due to the complex geometry of free‐form surfaces. A CAD‐guided chopper gun trajectory generation system for free‐form surfaces has been developed in our previous work. A complex surface has to be divided into several patches to satisfy the given constraints. Optimization algorithms are developed to integrate the trajectories of patches to form a trajectory for the free‐form surface. A thickness verification method is also provided to verify the generated trajectories. The results of experiments and simulations have shown that the trajectory generation system achieves satisfactory performance. This trajectory generation method can also be applied in many other CAD‐guided robot trajectory planning applications.

OPTIMAL TOOL TRAJECTORY INTEGRATION IN SURFACE MANUFACTURING

Abstract Automated CAD-guided tool planning has many applications in surface manufacturing, such as spray painting, spray forming, rapid tooling, cleaning and polishing. In our previous work, a general framework has been developed to automatically generate trajectories for a free-form surface for these tasks. Because of the complicated geometry of a free-form surface, it maybe partitioned into multiple patches. After trajectories for all patches are generated, they must be connected to form a complete trajectory. In this paper, the algorithm for automated optimal trajectory connection is developed and the optimal trajectory connection is formulated as an integer programming problem. Experimental tests have been carried out on automotive parts and the results validate the developed approach. This framework can also be extended to other applications such as material deposition using plasma gun.