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Many automated guided golf cars using the electromagnetic guide technology are used in Japan to obtain more convenient and safer golf play. Now this technology is beginning to be used outside of the golf course as an on-demand people mover system. This paper presents an example of the engineering system of automated guided golf cars along for the 2 principles of automated guided vehicle. The first principle is “the steering control system including the automatic sensitivity adjustment function”, and the other principle is “the vehicle speed control system”.

YAMAHA Motor has developed and marketed a hybrid bicycle with an electric supplemental power source which generates assist power in proportion to the pedal torque by riders. The key function required for this assist power control system is that the variation of the assist ratio should be as small as possible over wide range of riding conditions. The assist power control system consists of mechanical and electrical components and requires a very tight quality control of each component if the design fails to be robust to disturbances such as pedal torque or vehicle speed. We applied the Taguchi method to this development and succeeded in selecting the optimum combination of component levels in the system.

A control system for auto driving of motorcycle using anthropomorphic robot has been developed to efficiently evaluate a motorcycle with high accuracy, the performance of which is becoming higher. For magnetostriction-type load sensor, which is absolutely necessary for this system, the strain gauge type load cell has been used conventionally. However, the detection sensitivity, strength, and responsibility have not been satisfied completely under engine vibration conditions. To solve this problem, a magnetostriction-type load sensor has been newly developed. As a result of the tests with actual machines, it is found that this magnetostriction-type load sensor satisfies the conditions necessary for the motorcycle drive control system and measurement system.

Recently, there have been many reports about developing control systems that actuate engines and brakes based on friction circle. We are researching the control system for motorcycles, which adds the return torque of throttle grip based on it for informing the limit of tire grip on the driving wheel. This throttle grip is a haptic display, offers haptic signals by controlling the motor connected to the throttle grip as a HMI. From the results of riding tests, the system was found helpful for riders to control the throttle grip as well as feeling easy about knowing the limit of tire grip. But it is known that the friction circle of a driving wheel depends on the normal force which changes by the gradient of road, acceleration and so on. The compensated control for changing the normal force by gradient was made to improve the throttle grip control system.

With the hope of efficient and sophisticated motorcycle engine development, an engine test bed that can simulate vehicle running conditions using an ultra-low inertia motor and high response load control system was constructed, and was applied to the development of engines. By combining an exhaust gas analyzer, an exhaust gas constant volume sampler (CVS), and a data processing system, mass emissions could be measured in various test cycles. This system's advantages for data repeatability and test efficiency compared with a chassis test using a vehicle were confirmed. An acceleration test was conducted to assess running performance, and good agreement with actual driving values was confirmed. In addition, by measuring and evaluating engine response to throttle manipulation, it was possible to evaluate driveability on the test bed. These test findings indicate that this test bed can simulate vehicle driving tests with the engine only and will be a useful tool in engine development.

A centralized control system utilizing optical communication has been developed. Except for the ignition system, almost all electrical functions are under the centralized control. As a method of simplifying wire harness, the time division multiplex communication system using optical communication is adopted. As a result, this new system has made it possible to reduce the number of wires in wire harness from 174 to 123, that of connectors from 60 to 50, and the weight of the wire harness from 1,600 g to 1,350 g. In addition, this system has allowed to reduce the control units (relays) from 11 to 2 (excluding the ignition system).

1 Research was conducted on reduction of circuit inductance for the purpose of reducing the surge voltage generated during switching by FET (field effect transistor / semiconductor device) in the power modules of motor controllers for golf carts (Fig. 1) and other electric vehicles. The motor control system is composed of the battery, the motor controller, the motor, and the wirings that connect them, and the inductance exists in them altogether. It became clear from simulation analysis and measurements from a prototype that only the inductance within the motor controller among these composition parts influences the surge voltage. And it became clear that there is a correlation between surge voltage and the sum of the inductance of the electrolytic capacitor inside the power module and the inductance of the circuit by which current is supplied from the electrolytic capacitor to the FET.