Mathematical model for bale-density prediction in large steel roller-type round balers during bale rolling.

To realize the intelligent production of straw bales and improve their economy, the density of straw bales in the working process of large-scale steel roller-type round balers must be measured in real time. Therefore, this study analyzes the forces acting on steel rollers and bales in the bale rolling process, constructs a mathematical model to predict the density of molded bales, and proposes a method for dynamically measuring the density of bales in a round bale machine. Sunflower straw was selected as the test material, and a bale density model validation test was conducted at a test stand. The results showed that the accuracy of the measured bale density of the data acquisition system ranged from 93% to 97%, verifying that the mathematical model for bale density prediction had good accuracy. This study provided an effective strategy for round baler design.

Study on Contact Stress Distribution Characteristics and Damage of Plug Seedlings Based on Flexible Pressure Sensor.

At present, there is a problem that the growth quality is reduced due to damage to the plug seedling pot during the transplanting process. In this study, the pressure distribution measurement system was used to measure the contact area of plug seedlings when they collided with the ground. The effects of seedling age and forward speed on the characteristics of contact stress distribution and potting damage were investigated through a single-factor experiment. The results were comprehensively considered based on the single-factor test, and the Box-Behnken test was used to optimize the design. The matrix loss rate was used as the evaluation index to determine the optimal parameter combination for transplanting: the tray specification was 72, the seedling age was 30 d, and the forward speed was 1.25 km·h-1. This study can provide a reference and technical support for further research on pot damage in plug seedling transplanting. The optimized parameters can provide practical guidance for reducing pot damage and improving growth quality during transplanting plug seedlings.