Noboru Noguchi
Bio-production Engineering, Research Faculty of Agriculture, Hokkaido University

The plant factory is a facility that aids the steady production of high-quality vegetables all year round by artificially controlling the cultivation environment (e.g., light, temperature, humidity, carbon dioxide concentration, and culture solution), allowing growers to plan production. By controlling the internal environment, plant factories can produce vegetables about two to four times faster than by typical outdoor cultivation. In addition, more than 80 % water for cultivation can be saved by adopting the plant factory. But, to successfully control the environment within the plant factory, a skilled grower is still needed to decide various set-points for the cultivation environments, in particular, for a sunlight-type plant factory. Since the system disturbances of a sunlight-type plant factory such as sun light, wind, outdoor temperature, and humidity etc. are larger than a fully artificial light-type plant factory, an intelligent system replacing the skilled grower for environmental control is badly needed to ensure high yield and quality. To achieve this intelligent system for environmental control, the crucial technology is Speaking Plant Approach (SPA) with environmental control and cultivation systems. It is obviously important to measure physiological responses of the plant using sensors and then use that information for environmental control. It is, however, difficult to sufficiently address these tasks because plant responses are quite complex and uncertain, but intelligent control techniques can facilitate such tasks. The presentation introduces the concepts of the SPA, an intelligent control technique using the SPA, and their applications for optimizing cultivation.