The number of new vehicle models

One of the biggest challenges in today’s automotive production environment is the incorporation of multiple vehicles at the same plant in much higher densities than in the past. Since the demand for new vehicles is increasing every year, OEMs are adding new models and variants by increasing the production capacity of their existing plant.

Driven by the need to increase production capacity and shorten cycle time, manufacturers in numerous industries are taking advantage of various automation technologies. One of these automation technologies is Robotics. Automakers and automotive related industries particularly implement greater use of robots in their BIW assembly line, as their assembly lines are quite complex. Robots automate the production of various components and simplify most of the tasks on assembly line.

Consequently, to successfully apply robotics technology in BIW assembly line, there lay a stronger need for effective analysis and design tools. Robotic simulation is one of the digital manufacturing techniques that help to visualize entire robotic workcells and sort out any problems before investing in costly equipment. Robotic simulation is widely utilized in the automotive industry as their BIW assembly line involves multiple robots, tooling fixtures, humans, etc. that needs to be validated and optimized prior to system build to ensure that it will yield the desired results. Cost savings, safety and user interaction are some of the advantages that makes robotic simulation a valuable tool in the manufacturing industry.

Why Robotic simulation?

Robotic simulation is a technique of building a model of a real or proposed robotic workcell so that the robot’s behavior may be studied. It aims at visualizing and optimizing the performance of a robot in a manufacturing cell, and can help in validating layouts, cycle time estimates, balance multi robot lines, optimize floor space, and check tooling and fixture designs. Everything from cycle time to robot reach to tool validation is performed in simulation. Robotic simulation:

  • » Accelerates new product introduction (NPI)
  • » Ensures a working process
  • » Provides tremendous scope for optimization
  • » Facilitates collaboration amongst design, digital manufacturing engineers, and shop floor
  • » Eliminates costly mistakes
  • » Saves time

About BIW assembly line

Product BOM of the BIW skeleton consists of more than thousands components, which can be broadly divided in four major groups –

  • » Underbody assembly (assembly of motor compartment, front/rear floor, rear compartment, rocker)
  • » Closures (sub assemblies of doors, decklid, hood , fenders)
  • » Inner framing (assembly of bodyside inner, roof bow, shelf, rear-end)
  • » Outer framing (assembly of body side outer, roof, motor rail extension)

All these major components of vehicle body are assembled through robotic operations like material handling, geo spot welding, respot welding, arc welding, nut/ stud welding, clinching, dispensing, pedestal operations, vision system, hemming, tabbing etc.

Essential capabilities of Robotic Simulation in BIW assembly

The core activities of robotic simulation in BIW assembly are:

  • » Validate and optimize the Process
  • » Validate and optimize the Tools
  • » Validate and optimize Plant Layout
    1. Validate and Optimize the Process
      Robotic simulation is a powerful tool that helps in simulating the entire process and verifying that the robots can perform all the desired tasks efficiently. Automotive workcells usually have multiple robots that have to be sequenced properly to optimize cycle times and minimize interference zone wait times.
      A typical automotive BIW has several thousand weld spots to create the assembly from the individual sheetmetal stampings, and a significant amount of time goes in determining an optimum weld spot distribution between the robots. Robotic simulation addresses the early planning phase of spot-welding design process. It facilitates optimum weld spot sequence and distribution of weld points to multiple stations in a simulation environment. Similarly, other processes like material handling, dispensing and arc welding process sequences can also be validated and optimized through robotic simulation. The robotic simulation team works in close collaboration with the processing team to design and validate all processes in a 3D model. The simulation team analyzes alternate scenarios to identify a process with optimum cycle times. By simulating robot motions during design, the team verifies whether the robots will be able to achieve the required motions without interference and arrive at a realistic cycle time and throughput.