Recognition and 3D positional estimation of apples during harvesting from a robotic platform in a moving vehicle are still challenging. Fruit clusters, branches, foliage, low resolution, and different illuminations are unavoidable and cause errors in different environmental conditions. Therefore, this research aimed to develop a recognition system based on training datasets from an augmented, complex apple orchard. The recognition system was evaluated using deep learning algorithms established from a convolutional neural network (CNN). The dynamic accuracy of the modern artificial neural networks involving 3D coordinates for deploying robotic arms at different forward-moving speeds from an experimental vehicle was investigated to compare the recognition and tracking localization accuracy. In this study, a Realsense D455 RGB-D camera was selected to acquire 3D coordinates of each detected and counted apple attached to artificial trees placed in the field to propose a specially designed structure for ease of robotic harvesting. A 3D camera, YOLO (You Only Look Once), YOLOv4, YOLOv5, YOLOv7, and EfficienDet state-of-the-art models were utilized for object detection. The Deep SORT algorithm was employed for tracking and counting detected apples using perpendicular, 15°, and 30° orientations. The 3D coordinates were obtained for each tracked apple when the on-board camera in the vehicle passed the reference line and was set in the middle of the image frame. To optimize harvesting at three different speeds (0.052 ms−1, 0.069 ms−1, and 0.098 ms−1), the accuracy of 3D coordinates was compared for three forward-moving speeds and three camera angles (15°, 30°, and 90°). The mean average precision (mAP@0.5) values of YOLOv4, YOLOv5, YOLOv7, and EfficientDet were 0.84, 0.86, 0.905, and 0.775, respectively. The lowest root mean square error (RMSE) was 1.54 cm for the apples detected by EfficientDet at a 15° orientation and a speed of 0.098 ms−1. In terms of counting apples, YOLOv5 and YOLOv7 showed a higher number of detections in outdoor dynamic conditions, achieving a counting accuracy of 86.6%. We concluded that the EfficientDet deep learning algorithm at a 15° orientation in 3D coordinates can be employed for further robotic arm development while harvesting apples in a specially designed orchard.

Developing countries in Asia widely use manual seed broadcasting methods due to a lack of appropriate seeding machinery. The agricultural sector is currently facing labor shortages and high labor costs, especially seasonal labor shortages for broadcasting and transplanting operations. However, the primary constraint in adopting existing broadcasting seeders for small-scale farmers in developing countries is the high initial purchase costs. Therefore, developing locally commercial accessible technology for small-scale farmers is an urgent requirement. In this regard, attempt was taken to develop a new low-cost 3D printed seeder that can be used for multi-crop seed broadcasting operations when integrated with an autonomous terrain vehicle. A new seed metering mechanism was proposed for seed broadcasting that can be controlled electronically from the autonomous terrain vehicle. Positional sensors based on the real time kinematics—global navigation satellite system (RTK-GNSS) were used to record positional information. The best observation was noted at a vehicle operational speed of 0.351 ms−1 and had a coefficient of variation (CV) referring to the distribution uniformity of seeds of 19% for green peas, 22% for cowpeas, and 25% for chickpeas. The developed seeder could spread multi-crop seeds and adjust the seed rates electronically at the different ranges of rotational speeds. Therefore, the use of 3D printed fabricated prototype seed broadcasting units with small-scale autonomous vehicles can be implemented to help in labor supplements and perform the broadcasting of different seeds.

Chilli (Capsicum annuum), one of the essential ingredients in Sri Lankan cuisine, is widely cultivated for producing dried chilli. The narrow conical-shaped chilli pods with wrinkled surface do not support much of the existing common mechanical feeding systems such as augers or bucket conveyorsin the chilli processing plants. Therefore, the objective of this study is to design and develop a robotic arm with a proper grabbing technique to feed chilli into the grinding mill. Furthermore, it is intended to install the developed robotic arm in an industrial level processing plant to test the feasibility of theindustrial application.The industrial robot designed in this study is primarily composed of three parts: the base, the arm and the wrist. These components connect with joints to form a unit. At the end of the wrist, an end-effector, which is a gripper for grasping chilli pods, is located.ATmega328 microcontroller, micro switches and DC motors were used to operate the robotic arm. The feeding rate is automatically controlled using a Hall Effect sensor. The robotic arm grabber was placed on top of the chilli containing trough (2.5m wide, 10.5m long, and 1.25m high) of an industrial level chilli processing plant.When operating, the grabber could grab 1.640±0.128 kg of chilli from the bulk in a single operation. The average time taken for one complete cycle of grabbing chilli, lifting the grabber, turning the arm on to the conveyer and releasing chilli on to the belt conveyor, varies from 20 s and 30 s depending on the height of chilli in the trough. The feeding rate varies from 440.6 kg/h and 218.66 kg/h when chilli is grabbed from the top and the bottom layers respectively. Therefore, this system can be recommended for maximum feeding rate of chilli up to 218.66 kg/h. Capacity can be increased by adding the same mechanism parallel or scaling up the existing system.