Adaptive Impedance Control Method for Dynamic Contact Force Tracking of Robotic Excavators

Robotic excavators commonly are used in industrial and construction tasks to improve efficiency and shorten construction periods, but they have high energy consumption and vibration and shock problems, the greatest of which is impact phenomenon in contact with construction environment. A perfect construction task with low vibration and high precision can be achieved only by skilled operators, and requires very intense concentration. Due to the urgent labor shortage caused by the pandemic, tight schedules, and increasingly complex construction projects, it is important for construction management to have an intelligent control method that combines the force and position of excavators in the construction progress. This study developed an adaptive impedance control method to realize coordinated control of force and position. An adaptive impedance control was designed to adjust the impedance parameters indirectly. Three different simulations were conducted to compare the force tracking performance of the classic impedance control and the proposed adaptive impedance control, namely, environmental location changes, environmental stiffness changes, and dynamic force tracking. Blended contact surfaces were designed to validate the performance of the control algorithms. Results show that the proposed adaptive impedance control effectively improved the force tracking accuracy. This paper offers an original contribution to the intelligent control method of excavator construction, and will be of use to operators, especially in large ground, mine, earthquake, and other complex ground construction sites. In addition, the research also provides construction manager and other practitioners with an impedance control method in construction project management that can save labor cost, improve production efficiency, and accelerate the transformation to a digital and intelligent construction industry.