Dongjie Zhao

Design and experiments of a football field bounce rate detector

At present, detection of football bounce rate on football fields is mainly based on manual method in China, which is labor intensive and has low detection accuracy. To solve this problem, based on the photoelectric sensor arrays, an optical detection method is proposed for measuring football field bounce rate. A football clamping mechanism has been theoretically analyzed and then a simple and reliable football holding device was developed to perform clamping and release. A control system of the football field bounce rate detector has been constructed based on modular design principles. The detector was completed on this basis, which can achieve gripping, lifting, releasing football and bounce rate calculation. Experiments showed that the errors of detection accuracy of this equipment are not more than 1%, fully satisfying the relevant national standards.

Cam Drive Step Mechanism of a Quadruped Robot

Bionic quadruped robots received considerable worldwide research attention. For a quadruped robot walking with steady paces on a flat terrain, using a cam drive control mechanism instead of servomotors provides theoretical and practical benefits as it reduces the system weight, cost, and control complexities; thus it may be more cost beneficial for some recreational or household applications. This study explores the robot step mechanism including the leg and cam drive control systems based on studying the bone structure and the kinematic step sequences of dog. The design requirements for the cam drive robot legs have been raised, and the mechanical principles of the leg operating mechanism as well as the control parameters have been analyzed. A cam drive control system was constructed using three cams to control each leg. Finally, a four-leg demo robot was manufactured for experiments and it showed stable walking patterns on a flat floor.

Design and Test of a Solanaceae Grafting Robot

A grafting robot based on cleft grafting method has been developed to improve efficiency of grafting solanaceae vegetables. This robot consists of four parts including a clamping manipulator and carrying, cutting, feeding mechanisms. These not only enable the robot to conveniently perform clamping, carrying, positioning, cutting, joining, and binding rootstock and scion, but also improve the grafting efficiency. The average success rates for cutting rootstock, cutting scion and conjugation are 98.7%, 99.0% and 59.6% respectively. The developed robot was able to perform steady operations, suggesting potential value for practical applications.

Design of a Sapling Branch Grafting Robot

The automatic sapling grafting methods and grafting robot technologies are not comprehensively studied despite the fact that they are urgently required in practice. For this reason, a sapling grafting robot is developed to implement automatic grafting for saplings. The developed grafting robot includes clipping mechanism, moving mechanism, cutting mechanism, binding mechanism, and Arduino MCU based control system, which is capable of clipping, moving, positioning, cutting, grafting, and binding saplings. Experiments show that the stock cutting efficiency is 98.4%, the scion cutting efficiency is 98.9%, the grafting efficiency is 87.3%, and the binding efficiency is 68.9%.