The need for automated material handling inside the factory has been steadily increasing, especially due to implementation of intelligent manufacturing for better productivity and product quality. Automated material handling devices include logistics robots, automated guided vehicles, industrial robots, collaborative robots, and pick-and-place devices. This study focuses on the development of a low-cost logistics robot that works effectively within a simulated smart factory environment. A nominal PID controller is implemented to guide the robot to follow the line painted on the factory floor. The tracking error information is generated by four down-facing infrared sensors and is fed into the controller. The line-following performance is significantly improved with augmentation of a model-based friction compensator. Optimization of battery power depending on the remaining charge status enhances the reliability. All hardware/software development is supported by the Arduino platform. The step-by-step movement and performance of the logistics robot is verified inside the simulated smart factory environment that includes a robot arm, three conveyors, and two processing stations.

Since IBM introduced the first hard disk drive (HDD) with 5 MB capacity in 1956, tremendous advances have been achieved in HDD technology and business. The areal density has increased 650 million times in the last 60 years. To implement the digital servo systems for high capacity HDD, elaborate servo patterns should be written on the disk surface during manufacturing processes. This process is called servo track writing (STW). When the servo track pitch reaches 50 nano-meter, the position error resolution should be less than 5 nano-meter for the drive servo and STW operations. The STW technology is in the realm of nano-mechatronics and should address precision motion control and manufacturing issues. Initially, all STW process were conducted inside the clean-room using special STW equipment. With ever-increasing track density, as well as the STW time and manufacturing costs, the industry has developed the STW technology that could move the STW operation to the outside of the clean-room and eliminate special equipment. Many innovative STW technologies have been invented and successfully implemented such as conventional STW, multi-disk writers, printed magnetic printing STW, spiral STW and spiral-seeded STW. With the successful implementation of these state-of-the-art technologies, HDD production has become more efficient and flexible.

The International System of Units (acronym: SI) is founded on seven base units (meter, kilogram, second, ampere, kelvin, mole, and candela) corresponding to seven base quantities (length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity). SI was formally established in 1960 by the 11th CGPM. It has been revised from time to time in response to requirements of users and advances in science and technology. However, the most significant revision is going to be done in November 2018 by the 26th CGPM. Four base units (kilogram, ampere, kelvin, and mole) will be given new definitions linking them to exactly defined values of Planck constant, elementary charge, Boltzmann constant, and Avogadro constant, respectively. In this paper, historical background for the revision of SI is described and scientific principle of redefinition is explained. The procedure used to redefine meter from the speed of light in a vacuum is used as an example. After this revision, uncertainties of many other fundamental constants will be eliminated or reduced. From May 20, 2019 (World Metrology Day), the revised SI will come to practice.