Automation can address labor shortage and enhance worker safety in construction. However, workers continue to perform majority of the work at construction sites that can be automated. Construction machinery require force control for automation, which can absorb external shocks and provide appropriate forces along with environmental forces. This study proposes a force-controlled excavator that fulfills these requirements by replacing the hydraulic system with a series elastic actuator (SEA). Few studies have applied SEA to large high-output construction machinery. We designed the structure of the SEA to deliver high output power in a compact form that can be mounted on an excavator. A 2.5-T class excavator equipped with this SEA is designed, which achieved a force resolution of 15–35 N at the tip. The effectiveness of this excavator in automating a major portion of the manual work is demonstrated.

Safety can be listed as one of the most important aspects of every working environment, from the low risky to the most dangerous one. Construction sites can be clearly identified among the riskiest working fields, mainly because several complex and fast maneuvers are executed in a very crowded, dynamic and uncertain scenario. Specifically referring to construction machines, typical operations such as digging, earthmoving, heavy weights loading/unloading, etc. become incredibly risky if the machine stability is not guaranteed by the operator. To this purpose, this paper proposes a practical implementation of a dynamic fall prediction system for excavators based on the concept of the Zero Moment Point (ZMP). A commercially available excavator has been dynamically modelled and equipped with a set of sensors to reconstruct the state of the machine. When the proposed system is running, an alarm rings if a critical condition is reached, thus allowing the operator to avoid risky and potentially harmful situations.

TerraSAR-X is an operational and advanced SAR-satellite system for scientific and commercial applications that was launched on June 15th, 2007. DLR acquired the quadratic TerraSAR-X data in the Dual Receive Antenna Campaign in this year for scientific purpose. This study applies four-component decomposition with rotated coherency matrix which is a very efficient methodology for target detection and terrain classification.

The research of image-based control for nonholonomic mobile robots is a recent topic of mobile robots. There are few researches about image-based control of mobile robots with central catadioptric cameras. A central catadioptric camera is very effective to keep target objects in the camera field of view because of its wide area view. In this paper, a new image-based path following control method for a nonholonomic mobile robot with a central catadioptric camera is proposed in the image parameter space. It is confirmed by several simulation, indoor and outdoor experiments that the designed system has high performance and robustness in real world.