Optimization of a Farm Seeding and Fertilizing Spring-Loaded Four-Bar Mechanism

A Sequential Quadratic Programming technique was utilized to synthesize optimal performance of a spring-loaded four-bar mechanism that, when actuated, lifts a farm tillage implement out of the soil. Maximum lift and magnitude of actuation force were significantly improved over a current design. Computer-aided design was used to confirm that interference design constraints were not violated during optimization. In-field performance of the mechanism when encountering an obstacle was verified using a dynamic model to realistically simulate the event.

This paper presents efforts to improve performance of a spring-loaded four-bar mechanism through the application of computer-aided design techniques. When actuated, the mechanism allows a seeding and fertilizing implement to pivot out of the soil to avoid damage by some obstacle. The manufacturer of this device sought to improve its performance by increasing vertical displacement and maintaining a near constant driving force during actuation. These improvements would have a positive impact on reliability and productivity of the implement. Computer-aided design techniques were used to evaluate the current design, optimize the design variables to meet design criteria, and simulate “in-field” performance.