The biological energy research has been paid attention by lots of researchers nowadays. Many kinds of energy crops have been studied to produce liquid fuel. Miscanthus, as one of the most potential candidate, is been experimentally planted in Illinois of US. The biomass feedstock production, which is a subsystem of Energy Biosciences Institute project, has the engineering solution. So, a new gantry-like vehicle had been developed for crop close proximity monitoring. The growth information of Miscanthus can be collected by this vehicle which is equipped a multi-spectral camera. The close measurement increases the spatial and temporal resolution of the crop remote sensing data significantly, compared to aerial remote sensing system. The vehicle is 3 meters long by 3 meters wide and by 3 meters high which is able to rise up to 4 meters in response to the variation of the height of the Miscanthus. The customized four-wheel-steering and four-wheel-driving mechanism of the vehicle had been designed and built. It makes the vehicle flexible to move in the Miscanthus farm. The control system of the vehicle had been developed in both hardware and software. The pre-harvest sampling data of the crop derived by the multi-spectral sensor are used to establish a crop growth model to predict the optimum harvest window for quality assurance biomass feedstock.