Hirohisa Sakai

Development of a robot control method for curved seal extrusion for high productivity in an advanced Toyota production system

Recent Japanese enterprises have been promoting global production to realize uniform quality worldwide and production at optimal locations for survival amid severe competition. The authors considered the necessity of including the above method in the strategic application of the Toyota production system (TPS), and clarified Advanced TPS as the global production by manufacturing technology. In the future, reformation of the production workshops transformed by robotics and IT will be necessary in order to keep the same quality worldwide and production at optimum locations. Thus manufacturing technology had to be improved for mass production by developing the latest robot control methods. So far, the authors have established a robot control method for global production called RCM-EPC. RCM-EPC contains a three-core robot control method with (i) locus and speed control of the external point (-LSC), (ii) simulation for optimizing the operation position (-SOP) and (iii) constant speed control for robot movement (-CSC). Furthermore robots are applied to several applications in order to improve productivity and achieve a high-quality appearance. In particular, the authors here introduce an up-to-date glass-integrated curved seal extrusion (CSE), which is a new technology for use in manufacturing: the automobile-window mole as an example for Toyota – one of the most advanced automotive manufacturing enterprises in the world. With the demonstration of a 50% reduction in manufacturing costs using Advanced TPS, the authors have achieved high productivity and quality assurance in global production.

The robot reliability design and improvement method and the advanced Toyota production system

Purpose – To demonstrate the theory and effectiveness of reliability‐improvement countermeasures for line equipment, specifically industrial robots for automotive production engineering.Design/methodology/approach – Suggests an efficient method of life‐cycle maintenance. The defects of industrial robots are analysed using Weibull analysis.Findings – From the analysis, a strategy of countermeasures is framed for component screening, reliability design and lifetime estimation.Originality/value – This method has been implemented worldwide in Toyotas factories, and has produced a better operating life cycle for industrial robots.

Estimation of robot's life expectancy based on deterioration model and development of a CAE system

The burden of robot maintenance in the car industry (e.g. overhaul) is increasing drastically year after year. Although inspection and maintenance are indispensable in view of preventive maintenance, it is most important to accurately know the life expectancy of mechanical parts constituting a robot in order to execute the inspection and maintenance operations at the minimum investment. We therefore discuss the fact that the wear of gears is a dominant life expectancy factor of mechanical parts and we make observations on wear phenomenon in view of tribology. Based on the observations, we propose wear estimation models with improved lubrication and the improvement is applied to actual robots. In addition, we integrated the models with the robot off-line programming system and developed a CAE system capable of estimating the robot life expectancy at the time of preparation of robot teaching data.

Verification of Process Layout CAE System TPS-LAS at Toyota

Recent Japanese enterprises have been promoting “global production” in order to realize “uniform quality worldwide and production at optimal locations” in an environment of severe competition. In recent years, digital engineering and computer simulation concepts have expanded to include, not only product quality, but also the quality of business processes and company management, while the scope of business administration activities has been widened. Considering the production environment surrounding the manufacturing enterprise, the authors have established a strategic manufacturing technology for Lean Production called TPS-LAS (Toyota Production System-Process Layout Analysis Simulation) by using Process Layout CAE System. At this stage of the investigation, this paper concentrates on verifying the effectiveness of the authors’ proposed TPS-LAS in Toyota’s manufacturing technology.