Driving unit design and motion analysis for a spiral propulsion mechanism in wetlands

Abstract

Environmental problems related to wetlands have attracted strong concern around the world during past decades. Mobile mechanisms of many kinds have been developed to satisfy demands of environmental investigation of wetlands. However, few researchers have studied spiral propulsion mechanisms. Our previous work showed that the spiral can move forward between gaps of plants, giving only very slight damage to plants. It is introduced to be used to carry measurement devices in wetlands when investigating the current state of wetlands. This paper addresses the development and performance analysis of spiral driving units, which rotate the spiral by gripping its circumference and moving it forward or backward. A method to analyze the attitude angle and traveling distance of the spiral without a center axle is proposed. The kinematic relations between the driving unit and spiral are established on the premise of data from a motion capture system. Experimental results for driving units of two kinds are discussed, with emphasis on attitude stability, technical feasibility, and repeatability. Results show that the proposed driving units can drive the spiral to rotate forward along the desired direction as expected.

Keywords

• spiral
• screw
• wetlands
• kinematic
• driving unit
• mechanism
• motion capture system