Shun-ichi Hata

Feedback Control of Manipulator Using Machine Vision for Robotic Apple Harvesting

The challenges in developing a fruit harvesting robot are recognizing the fruit in the foliage, detaching the fruit from the tree, and the coordination of the vision system and the hand system. This paper presents the development of a feedback control of manipulator using machine vision. To measure the distance of the fruit from the camera, the laser ranging sensor is used. The detected fruit should be in the center of the image for its distance to be measured, so the camera should be positioned using the manipulator to position the fruit in the center of the image. A feedback control using machine vision is used for this positioning procedure. Two controllers are considered; threeposition on-off controller and proportional controller with variable gain. Both controllers were implemented in a simulation. Simulation results showed that both controllers were able to guide the manipulator to position the fruit in the center of the image.

Automatic detecting system of apple harvest season for robotic apple harvesting

The objective of this research was to develop the automatic detecting system of apple harvesting season for the robotic apple harvest. The farmers check the fruit color, when they harvest the apple fruits. The fruit color is the most important function to decide the suitable fruit harvest time. This detecting system should be installed to the apple harvesting robot. The color of apples that were suitable season to harvest and earlier season to harvest, were measured and comp aired using the spectrophotometer. The harvest season apple showed chromatic red color, and the earlier apple fruit of harvest included the yellow portions on its surface. The harvest season apple’s color and earlier apple’s color were well separated based on the Munsell color system, the L*a*b* color space and XYZ color system. The threshloding which detect the apples at the harvest time would be produced based on the evaluation of these color system. In addition, the chlorophyll contents (SPAD values) of apple tree leaves were also investigated during the apple cultivation. The highest SPAD values showed in the beginning of September. This was the just after the fruition season. The values were, then, decreasing until the harvest season. The variance of chlorophyll contents of apple tree leaves was also used for detecting the suitable harvest season of apples.

Plasma cyclic nucleotide responses to insulin-induced hypoglycaemia and methacholine in patients with hyperthyroidism

Abstract. The effect of insulin‐induced hypoglycaemia and methacholine on plasma cAMP and cGMP levels was studied in normal volunteers, hyperthyroid and hypothyroid patients. A significant positive correlation existed between the maximal increase in plasma cAMP and the maximal decrease in plasma glucose in normals during insulin‐induced hypoglycaemia. Therefore, the plasma cAMP response is considered to be dependent on the degree of hypoglycaemia, rather than the dose of insulin. The cAMP response to hypoglycaemia was significantly higher in hyperthyroid patient, and was lower in patients with hypothyroidism than in normals. The cAMP response of the hyperthyroid patients was normalized when their hyperthyroidism was controlled after 3 months of treatment. The plasma level of cGMP was slightly elevated during hypoglycaemia, but there was no significant difference between controls and hyperthyroid patients. The cGMP response to methacholine, which is probably mediated by cholinergic receptors, was significantly potentiated in hyperthyroid patients. The cAMP response, which is presumably dependent on endogenous catecholamines secreted during metha‐choline‐induced hypotension, was also enhanced in hyperthyroid patients. It is likely that β‐adrenergic receptor responses and cholinergic receptor responses are both enhanced in hyperthyroidism.

Development of Continuous Soil Sampling Machine System

The continuous soil sampling machine system was designed and developed. This is used for making the soil map for the suitable crop cultivation and management. The advantage of this system is that the actual soil is sampled for the analysis. The concept of this machine system is that the machine system travels during the soil sampling. The target traveling velocity is set to more than 1.0 m/s. This soil sampling machine system consists of three parts which are the rotary, the soil transport line and the can transport line. The tractor drives this system. The operation of this system is as followed; The rotary tills the field and throws backward the pulverized soil to the soil transport line. The soil transport line transports the soil to the can that takes the soil. The motion of the can transport line is controlled and the soil is sampled at constant interval or at pre-scheduled locations. The motion of the can transport line is driven by the one-chip microcomputer, named as PIC, based on the GPS data. As the results of the experiment, this soil sampling machine system showed a good performance in taking the pulverized soil.

Plasma cyclic 3′,5′-guanosine monophosphate and cyclic 3′,5′-adenosine monophosphate response to methacholine in man

Cholinergic agents are known to induce increases in tissue and plasma levels of cyclic GMP in experimental animals. We observed that i.m. injection of methacholine, a cholinergic agent, caused significant increases in plasma cyclic GMP and cyclic AMP in man.

Development of Mapping System of Crop Growth

The method how to get the information of the crop in the growing stages is one of the important things in the Precision Agriculture. For example, the obtaining information of the crop’s dry matter and the height at the site specific in the field leads to make the decisions of the amount of the fertilizers and the further crop management schedule. The remote sensing technology is needed for the measurement of the information because of the low tasks and the real time sensing. The goal of this research is to determine and estimate the crop growing status from the images. The crop status was measured and estimated using the vision system. The crop size could be estimated from the captured image. The algorithm to montage the entire crop row image from the continuous digital captured images was developed. The accuracy of the montage image showed good performance. The growing of the crops within the crop rows was also estimated comparing two montage images. This was able to use for the evaluation of the trend of crop growing in each growing stages.

Theoretical analysis of a wheel driven root crop harvester

Abstract A prototype of a wheel driven trailer was developed to simulate a wheel driven trailed root crop harvester. The mobility of the prototype tractor-trailer system was improved by driving the trailer wheels by a mounted engine. A mathematical model to predict the mobility and the stability of the system was developed. The model was validated by field experiments conducted in plowed, rotary tilled and untilled fields. The model was found to predict performance with a high accuracy. Parameter studies were conducted to investigate the effects of several design parameters, such as the peripheral velocity ratio (Rs), the weight of the trailer (m1), the trailers C.G. location (LL) and the height of a hitch point (h), on the mobility and the stability of the system.

Studies of the Relationship Between Renin Secretion and the Sympathetic Nervous System Responsiveness in Man

: In recent years many investigators have reported the role of the sympathetic nervous system and the catecholamines in the regulation of renin secretion. It has been recently reported that plasma dopamine-beta-hydroxylase (DBH) excreted through the mechanism of the exocytosis with noradrenaline from the sympathetic postganglionic nervous endings is a mirror of the function of the sympathetic nervous system. In this investigation, blood pressure, urinary catecholamine excretion, plasma DBH activity and plasmsa renin activity (RPA) have been determined in normal individuals during the mecholyl test and insulin-induced hypoglycaemia. In the mecholyl test, plasma DBH activity and PRA markedly increased in five males who showed prominent responses of systolic blood pressure to mecholyl (S type) and changed slightly in eight males who showed minimal responses of systolic blood pressure to mecholyl (N type). It showed that there was a significant relationship between the maximal percent increases from their respective control values of plasma DBH activity and those of PRA following mecholyl. In insulin-induced hypoglycaemia, plasma DBH activity, blood pressure and PRA remarkably increased following a large dose of insulin administration (0.15 u/kg). In a dose of 0.1 u/kg, there was no significant increase of plasma DBH activity and blood pressure. PRA singificantly increased but was lower than a large dose of insulin. Also, it showed that their was a significant relationship between maximal percent increases from their respective control values of plasma DBH activity and those of PRA following insulin administration. These data indicate a close correlation between changes in plasma DBH activity and those of PRA during mecholyl and insulin-induced hypoglycaemia and lend additional support to the concept of sympathetic nervous system mechanism of renin secretion.

Crop-Row Detector for Automatic Guidance Systems

Abstract The purpose of this study is to develop a crop-row detector that can be applied to row-following control systems. In this report, the feasibility of a new method for detecting crop rows and the practicability of a trial row-following control system are discussed. Results indicate that the crop-row detector is both accurate and quick enough for practical use. In addition, the trial row-following control system appeared to work profitably at low traveling speeds.