Laser Beam Control Mechanisms
- Paper number
IAC-05-C3.2.10
- Author
Mr. Christian Schaefer, Kobe University, Japan
- Year
2005
- Abstract
Since laser and photovoltaic (PV) technology improved in the last years, Laser Power Transmission (LPT) becomes more attractive for wireless power transmission applications. Total energy transmission efficiencies of 10In the last two years, several LPT experiments were demonstrated. A laser was directed to a mobile receiver (a vehicle or a plane) to demonstrate a possible application for this technology. Possible scenarios applying LPT could be an energy transmission between satellite – satellite, satellite – rover or power station – rover on a planet or a moon. As relative velocities are important in possible applications, beam deflection and steering plays an important role in LPT technology. To improve in these techniques, an experimental setup is planed where a rover will be constantly powered by a transmitter station over km distances. The purpose is to meet all requirements for the lunar polar mission. This paper describes the experimental setup emphasizing at the beam deflection principle and the control mechanisms. Several beam deflection principles, such as mechanical piezo - mirrors or galvano mirrors, can be applied in order to get control of the laser beam with relative high resolution and low response time. Non-mechanical beam steering is desired but still suffers of too high losses and small angles or tiny structures. A finding process allocates the target by hitting the attached laser reflectors. In controling the beam divergence, the spotsize can automatically be adjusted to the size of the PV area. The control mechanisms are desired not to use visual data because by using large distances in space, very big optical elements have to be implemented to reach high resolutions. Subsequently the beam’s position at the receiver is determined by measuring the intensity profile on the PV area. Important parameters for control mechanisms are the tracking speed and the precision. As the laser beam has to hit the photovoltaic area as precisely as possible to ensure a constant energy flow, non-linear control processes have to be applied due to the gaussian intensity profile of the laser beam spot. The control mechanism can be supported by an estimator which predicts the position of the receiver in using previous values. The deviation of predicted and given values can be used for changing the estimator’s parameters as well as to adapt the control mechanism.
- Abstract document
- Manuscript document
IAC-05-C3.2.10.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.