Defining a Winch Assembly

A winch assembly is simply a set of connectors connected to a winch. Such an assembly is defined by the command 


     ASSEMBLY WINCH, WINCH_NAME, EL(1), ........, EL(i) -OPTIONS

Here, WINCH_NAME is the name you wish to give to the winch assembly, and EL(i) are previously defined connector element names. The connector elements must be either B_CAT elements, H_CAT elements, or the element connecting the boom to the hook on a tip-hook assembly.

Here the options are either 


     -WINCH FULL_WEIGHT, MAX_TORQUE, S_MOMENT, D_MOMENT,  \
     TOT_LENGTH, FULL_GYRADIUS, FULL_RADIUS

or 


     -VELOCITY, V_SET, V_MULT

The first of these define the mechanical properties of the winch and alternatively the second defines the velocity of the winch as a function of time. Here, FULL_WEIGHT is the weight (feet or meters) of the drum plus the wire.The next three values define either the maximum applied torque, MAX_TORQUE, maximum applied torque or two moments applied by a brake. S_MOMENT is the static moment due to the brake and D_MOMENT is a factor which when multiplied by the square of the angular velocity is the dynamic moment due to the brake All three of these are in bforce-blength. The last three values are: the total length of wire on the drum, the radius of gyration of the drum plus wire when full, and the radius of gyration of the drum plus the wire when the winch is full in feet or meters.

The -VELOCITY option defines the velocity of the winch as a function of time. Here V_SET is the name of a CT_LENGTH "curve" that defines the rate of change of length (feet or meters/sec) of the line and V_MULT is a factor by which the curve will be multiplied.

Once an assembly has been initialized, the values can be altered with the internal command: 



     &CONNECTOR,  :CONN_SEL  -L_DYNAMIC, ACTION, MULT, BOUND

where :CONN_SEL selects the winches to be altered. Here ACTION must be either MOTOR, BRAKE or the name of a CT_LENGTH "curve" that defines, For the first of these, the MAX_TORQUE will be multiplied by MULT and the winch motor will be turned on and the brake will be released. For the second, S_MOMENT and D_MOMENT will but multiplied by MULT and winch motor will be turned off and the brake will be engaged. For the last action, the velocity curve will be multiplied by MULT. Here, BOUND is a bound on the line length. If MULT is greater than zero (letting out line) the BOUND is an upper bound on the line length. If MULT is less than zero (letting in line) the BOUND is an lower bound on the line length.