Precision farming and agricultural practices that take into consideration the protection of the environment have brought forward a number of research challenges. The scale of sampling and the precision required by such new agricultural practices are often higher than those required by traditional agriculture, increasing production costs. Methods and devices for on-the-go measurements are being developed to equip agricultural vehicles to support these practices. The proposed project was guided by the demand for research on autonomous vehicles and mobile agricultural robots to support the implementation of field measurements. The proposal sought to improve the gantry structure and the navigation system of a mobile agricultural robot developed in a partnership between Embrapa Instrumentation and the Mechanical Engineering Department of the University of São Paulo's São Carlos School of Engineering.