An Agricultural Robot for Multipurpose Operations in a Greenhouse

A multipurpose robot was designed to perform several tasks such as spraying and weeding in a greenhouse. Several operations were conducted by adding or removing sensing component(s), replacing actuator(s) and switching control software, with little or no change of the platform. A sliding mode control was applied to control motion of the robot in light of its kinematic model. Vision based algorithms were developed for navigation and operations of row planting crops, taking operations of spraying water and weeding by machine as examples. A vertical projection method was applied to calculate a guidance line for navigation. Preliminary tests were conducted to assess both guidance and operations of spraying and weeding in a greenhouse with green vegetable, respectively. Results showed that the robot traveled with a maximum lateral error of 47 mm, and sprayed with a productivity of 16-20 plants/min. Also, weeding action was taken in time. The designed robot has adaptability and versatility because the different operations can be achieved on the same platform.