1. TOP
  2. Research & Development
  3. Technology of Hitachi Zosen
  4. Control System

Control System

Hybrid Power Generation System

Even today, diesel engine generators are the mainstream of power supply systems in small, independent grids such as on remote islands. Such places, however, require a system that realizes reductions in both environmental burdens and fuel costs. Hitachi Zosen Corporation proposes a hybrid power generation system that combines diesel engines with natural energy such as solar power (Figure 1). The strong points of our diesel engine are that it operates continuously at a lower load of 10% and that it runs on bio-fuels such as palm oil.
On the other hand, the power output of natural energy fluctuates greatly depending on weather conditions such as sunshine and the wind. This power fluctuation may have a bad influence on the quality of electric power (voltage and frequency) and may even cause a power failure, particularly in a small-scale grid. Therefore, we are developing a control system that will level out the fluctuating output of natural energy with a minimal use of batteries and an appropriate use of the diesel engine, and thereby maintain the quality of electric power across the hybrid power generation system.

<Precision Laboratory, Technical Research Institute>

Figure 1 Hybrid power generation system

The Development of Food Sorting Equipment

We developed food-sorting equipment that removes foreign objects that are mixed with food by applying the image processing technology.
The inspection object of this equipment is foods such as marine products and vegetables.
The foods have various colors and forms, and contain many kinds of foreign objects. Therefore, inspection is more difficult than a general industrial product inspection. For example, the form of dried young sardines is complicated; they are neither a simple round shape nor a quadrangle. The color elements of dried young sardines are similar to that of wood chips.
We analyzed the form and color features of dried young sardines and foreign objects, and developed an algorithm capable of identification an instant. The speed of the conveyor belt of this equipment is 100 m/min, and the throughput reaches 200kg/h at the maximum.

<Precision Technology Group, Technical Research Institute>

The Development of Food Sorting Equipment

The inspection object

Real-time Tsunami Monitoring by GPS Tsunami Meter

GPS Tsunami Meter aims to mitigate the Tsunami disasters by in early times detecting and announcing the incidence of Tsunamis to coastal areas before those arrivals. For this purpose, GPS Tsunami Meter utilizes floating buoy as observation instrument, in which GPS antenna is attached on the top of the buoy body. Real -Time Kinematic GPS positioning method serves as a core technique for observing tsunamis. The concept of GPS Tsunami Meter is depicted in Figure.1. This system has received The Invention Prize at the National Commendation for Invention in 2010. ("GPS Tsunami Monitoring System" PAT. No. 3803177)
Various period waves are included in observation raw data of GPS Tsunami Meter. In order to separate tsunamis from raw data in quasi real time, Digital Filter (Finite Impulse Response Filter) technique and Harmonic Analysis technique are applied for eliminating short period waves and long period waves such as tide-level variations. Observation raw data and filtered data that include tsunamis are shown in Figure.2.

<Precision Technology Group, Technical Research Institute>

Fig.1 Concept of GPS Tsunami Meter

Fig.2 Hydraulic model experiment

Development of APC Controller for Vacuum Chamber Penduroll Valve

In semiconductor fabrication equipment, reactive gas is supplied to a vacuum chamber with a prescribed degree of vacuum, where etching processing is done on the surface of the wafer. The vacuum chamber in this equipment has a gas supply system and a gas exhaust system, with a turbo pump and a variable conductance valve upstream of the turbo pump. The valve aperture is adjusted to maintain the target pressure in the chamber (Figure 1). In manufacturing processes such as for semiconductors, the pressure controller (Adaptive Pressure Controller, or APC) is indispensable.
VTEX Corporation has been marketing as a set its own exhaust conductance adjustment valve (Penduroll valve) and an overseas-manufactured APC controller for eight years. However, in view of the demand for speedy technical support and enhanced performance and functionality, VTEX Corporation and Hitachizosen Corporation have jointly developed in-house an APC controller for Penduroll valves.

<Precision Technology Group, Technical Research Institute>

Fig.1 APC controller

Continuous Observation System Using GPS Precise Positioning Technique

The GPS precise positioning technique has come to be used widely for various purposes such as monitoring of crustal movement, a disaster recovery site (Figure 1), and huge structures under construction. The observation data from GPS receivers installed in some observation stations are sent to an analysis center through a relay station. At the analysis center, the precise coordinates of the observation stations are calculated in real time by using RTNet software, which has been developed by GPS Solutions, Inc. The calculated coordinates can be viewed over the Internet by an authorized customer (Figure 2).

Previously, it was necessary to use the dual-frequency GPS receiver, which is expensive, for the above purpose. We have developed a compensation technique to eliminate the ionospheric influence; the technique involves the use of observation data from a nationwide network of GPS stations operated by the Geospatial Information Authority of Japan. As a result of the elimination of the ionospheric influence, the single-frequency GPS receiver, which is economical, can be used. Moreover, we are developing a trend estimation filter for eliminating observation noise from the positioning result and are devising a technique for displacement detection.

<Precision Technology Group, Technology Group, Technical Research Institute>

Figure 1 Monitoring of a Disaster Recovery Site

Figure 2 Web Browser Monitor

Automatic and Continuous Analysis System of Heavy Metals in Fly Ash

The soot and dust, which we call "fly ash," from a municipal solid waste treatment facility include toxic heavy metals in high concentrations, and therefore, they should be treated for enhancing their anti-scattering properties and preventing the elution of metal particles. Additionally, the concentrations of toxic heavy metals in fly ash vary depending on the composition of the waste and the operating conditions of the furnace and gas treatment equipment. Hence, monitoring changes in the concentrations of heavy metals in fly ash is very important for not only ensuring conformance to leaching regulations but also monitoring the operating conditions.

We have developed an automatic continuous analysis device for the analysis of concentrations of heavy metals in fly ash. An X-ray analysis system and a very simple sampling machine that helps in handling fly ash powder without difficulty are used. The appearance of the device and a schematic of the installation of the device in a facility are shown in figure 1, and the accuracy of the analysis is shown in figure 2. This technique is applicable to other materials, for example, bottom ash and slag, for determining the heavy metal concentrations.

By using the developed device, we can improve the safety and reliability of furnaces and gas treatment equipment

<Environmental Solution Technology Group, Technical Research Institute>

Figure 1 Schematic of the installation of the device in a facility

Figure 2 Degree of analysis accuracy