Vehicle Dynamics Associated with Submarine Rescue 



This hovering and mating operation puts the DSRV in a new 

 and growing class of submersibles which because of their missions, 

 are required to hover, work, search, and otherwise maneuver at 

 low speeds. This requirement for low speed, high angle of attack 

 maneuverability is far outside the range of operation of the conven- 

 tional fleet type submarine and consequently analysis designed to 

 predict the dynamic behavior of conventional submarines is not com- 

 pletely applicable to the prediction of motions of the DSRV and other 

 submersibles of the same class. The adequate prediction of the 

 DSRV dynamics requires six degrees of freedom and a simulation 

 capable of predicting the forces and moments at high angles of attack 

 wherein the vehicle will experience lateral forces equal in magnitude 

 to the axial forces* To be useful, the simulation must be precise 

 enough for use in the design of the automatic control system. The 

 operational environment is also quite different from that normally 

 simulated in that the vehicle must hover and maneuver in currents 

 at near zero forward speed and in the presence of the disabled sub- 

 marine which causes considerable disturbances to the flow field. 

 This paper, which is divided into three general parts, presents one 

 approach to the simulation of the dynamics of a highly maneuverable 

 submersible. The first part describes the simulation of the free- 

 streami vehicle dynamics or the' dynamics outside the Influence of 

 the distressed submarine. The second section deals with the Inter- 

 action forces and moments caused by the presence of the distressed 

 submarine and Includes a discussion of a test program conducted to 

 measure these forces and moments. The third section describes 

 the application of the resulting equations of motion In conducting a 

 man- In- the -loop simulation of the DSRV motions during the mating 

 maneuver. 



The equations of motion were developed at LMSC and pro- 

 grammed on a Renmlngton Rand li03A computer. They were used 

 to determine the preformance characteristics of the vehicle to be 

 used In design studies and to provide equations of motion for use In 

 the control systenn development. The Interaction forces were 

 measured In the 12-foot variable pressure wind tunnel at the Ames 

 Research Center In Mountain View, California, Tests of this nature 

 were necessary due to the lack of data on Interaction forces and the 

 possibility that these forces would provide a significant Influence on 

 the vehicle and control system design. The manned simulation was 

 performed at the Marine Systems Division of the Sperry Rand 

 Corporation to provide demonstration of the ability to manually con- 

 trol the DSRV within the limits necessary for mating and to deter- 

 mine operational limits for this mode of operation. 



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