Dynamics and control of the tether elevator/crawler system

Dynamic multibody modeling for tethered space elevators

“…Lorenzini et al [6] considered an elevator/crawler system for controlling the gravity level onboard a space station. Their system considered two tethers, one deployed above the station and another deployed below the station.…”

“…However, even in the absence of such strong materials, smaller scale space elevators have applications that extend beyond transport to geosynchronous orbit. Examples include conducting microgravity experiments from the space station [5,6], retrieving satellites without retrieving the full tether, or for capturing noncooperative satellites [7,8].…”

Mission-function control of tethered satellite/climber system

“…The model assumed for SE in [20,21] was a rigid ribbon, which included libration of SE, but did not consider bending at the climber position, although bending occurs for a flexible tether because of the Coriolis force. Instead of the rigid ribbon model, more suitable models for treating bending of tether at the climber position are two bar model [22][23][24][25], three-bar model [26], and multibody model [27,28]. Kojima et al [24] studied the effect of climber moving constant velocity on the dynamic behavior of a two-bar modelled TSS.…”

“…However, as mentioned above, tether models in [20,21] were rigid ribbons, thus they did not reflect to the fact that the tether can bend at the climber position due to the Coriolis effect of the traveling climber. Considering that the tether can bend at the climber position, Misra et al [22] presented three simple climbing procedures, Modi et al [23] presented a linear quadratic regulator (LQR)-based thruster control, and Lorenzini et al [26] presented a modified hyperbolic tangent control law with the addition of a constant velocity phase.…”

Modeling of tethered satellite formations using graph theory

“…Several potential applications have been investigated in the literature. An elevator system for a space station using tethers was investigated in [2] and space elevators connecting Earth and space were suggested in [3]. Tether systems were proposed as atmospheric probes in [4], for interferometer missions [5], for space webs [6], and tethers are being considered for solar sail electric propulsion [7].…”