

Articles
by
Affiani Machmudah 
Total Records (
2 ) for
Affiani Machmudah 





Affiani Machmudah
and
Setyamartana Parman


This study addresses a pointtopoint of an arm robot motion planning in complex
geometrical obstacle considering all kinematics and dynamics constraints. A
continuous function of a seventh degree polynomial is utilized as a joint angle
path. The path planning optimization objective is to minimize a joint angle
traveling distance under avoiding collision constraint. After the best path
has been discovered, the trajectories will be optimized with an objective is
to minimize the total traveling time and the torque under the maximum velocity,
the maximum acceleration, the maximum jerk and the maximum torque constraints.
Three Degree of Freedom (3DOF) planar robot will be utilized to simulate the
proposed method. The computational strategy utilizing a Genetic Algorithm (GA)
will be presented. There is no information regarding the region of the feasible
seventh degree polynomial joint angle path so that the GA should search it first.
At the first computation where the population is generated randomly, all individuals
commonly collide with obstacles. It needs a requirement to escape from zero
fitness. After the feasible individual has been discovered, the GA should evolve
this individual to find the best one with the highest fitness value. Results
show that the feasible joint angle path which is very smooth in the motion has
succeeded to be found. The trajectories are also discovered successfully without
exceeding the constraint values. 





Setyamartana Parman
,
Bambang AriWahjoedi
,
Edward Halawa
and
Affiani Machmudah


Attitude maneuvers of a Communication Technology Satellite
(CTS)like spacecraft using constantamplitude thrusters is of great importance.
The spacecraft consists of a rigid main body and two symmetrical solar panels.
When the panels are large, they cannot be treated as rigid bodies anymore. They
are supposed to behave structural flexibility. To discrete their motion, the
finite element method is followed. Under constantamplitude thrusts, steadystate
attitude angle oscillations may occur in large amplitude after the maneuvers.
Since, the spacecraft should point to the earth precisely, these oscillations
must be reduced into small permissible values. To reduce residual attitude angle
oscillations, Proportional Derivative (PD) based constantamplitude input shaping
logic is proposed to determine time locations of thruster switching. Then, under
such inputs, attitude maneuvers of the spacecraft are simulated numerically.
Results of simulations show that the precise orientation of the satellite can
be achieved. 





