Makoto Shiozaki

Piezo-actuator shock absorber damping force controlling system having abnormality detection function

A shock absorber system for controlling the damping forces of shock absorbers comprising a drive apparatus for operating a piezo-actuator which is constructed by laminating a plurality of piezoelectric elements. The drive apparatus comprises a high-voltage generation circuit for generating a high voltage and a charging and discharging circuit for applying the high voltage, generated by the high-voltage generation circuit, to the piezo-actuator and for discharging an electric charge charged in the piezo-actuator due to the application of the high voltage thereto, the charging and discharging results in expansion and contraction of the piezo-actuator. Also included in the drive apparatus is an abnormality detection circuit for detecting a charging current or a discharging current passing through a charging or discharging current passage coupled to the piezo-actuator at the time of charging or discharging by the charging and discharging circuit. The abnormality detection circuit determines an abnormality of the drive apparatus when the detected charging current or discharging current is below a predetermined value.

Development of a fully Capable Electronic Control System for Diesel Engines

Introduced herein is an electronic control system for controlling an in-line fuel injection pump by the use of microcomputers and a servo mechanism for high precision positioning of a control rack is introduced. In the system a new control method of atmospheric pressure compensation is applied. The method maintains steady engine performance under any atmospheric pressure. A digital servo based on the modern control theory is employed as a servo mechanism for positioning the control rack in the fuel quantity control so that capability of the servo system is enhanced.