Vol. 85, No. 6
Abstract
Research on Control of Robot Tractor in Cyber-Physical-System
[Keywords: robot tractor, cyber-physical-system (CPS)，autonomous driving, latency compensation, kinematic model, vision sensor]
To control the steering of a robot with the help of a cloud computing infrastructure, there is a delay due to the network and the enormous quantity of calculations. So, in this study, we sought to develop a method that estimates lateral error with delay based on the geometric model and using the estimated value for steering control. The lateral error estimated by this delay compensation method was accu- rate to 0.04 m, providing adequate estimation accuracy. In addition, when a machine vision-based steer- ing control system was deployed in the cloud and delay compensation was implemented, displacement accuracy was improved by 76%. These findings indicate the efficiency of the transmission delay com- pensation system based on the robot’s geometric model.
Examining Load on the Top Plate of a Combine for Multi-crops during the Harvesting of Feed Corns through Rosette Analysis and DEM
[Keywords: combine harvester, triaxial strain gauges, collision, feed corn, numerical analysis, threshing section, DEM, load, rosette analysis]
Combines for multi-crops might have insufficient strength on the top plate of the threshing section during corn harvesting. This study examined the load on the top plate through rosette analysis and DEM. The results showed that the average von Mises stresses peaked at slightly forward position of the middle of the top plate, reaching a maximum stress of 88.5 MPa on the front side. The load direc- tion approximately followed the circumferential direction of the threshing drum. The safety factor of the top plate was 1.34-2.19 when a von Mises stress of 201 MPa was measured. DEM analysis showed that large loads resulting from sandwiched collisions were concentrated on the front side; this finding is consistent with the rosette analysis.
Analysis of Electricity Demand during Nighttime Cooling and Establishment of Year-Round Energy Management Indices in a Solar-Light Plant Factory
[Keywords: solar-light plant factory, heat pump, nighttime cooling, electric energy demand analysis, energy conservation, energy management, energy management index]
Investigations conducted in a solar-light plant factory cultivating tomatoes using air-source heat pumps revealed that nighttime cooling could be performed with less monthly electricity consumption and monthly electricity demand than those of heating. We proposed an energy management index
(daily area intensity)，calculated monthly for one year, to evaluate the electricity consumed to main- tain the required temperature environment in the cultivation facility. Moreover, we proposed an index
(daily saleable yield intensity)，calculated for each month in the harvest period, to evaluate the com- patibility between increasing the saleable yield and reducing electricity consumption. The electricity consumption per unit area and electricity consumption per unit saleable yield during cooling were approximately 40 ％ and 12 ％ of those during heating, respectively.
Consideration for Utilization of Danger-experience-type Materials in Agricultural Safety Education
[Keywords: virtual reality, danger-experience-type, agricultural safety, education, safety awareness]