Keywords

• all geometry
• single function
• multi parameter
• constrained optimization
• function or path
• mass, stiffness
• position of mass
• peak, RMS, average

The optimization module of SAM Professional offers constrained single-function multi-parameter optimization. Constraints are a combination of rules defined by the user to refuse specific solutions. The user defined expressions offer an unlimited area to describe these rules. Simple default constraints like x,y positions, masses or gear ratios are available via short user interface interactions.

As an example SAM can optimze the mechanism such that a certain linkage point follows a predefined path as good as possible. Parameters for this process are multiple x,y postions of nodes, choosen by the user. SAM runs the optimization fully automated and at the end presents the best solution.

Another application is to minimize the peak or RMS value of the driving torque by adding a compensating mass and let SAM determine the optimal value of the mass and its position. In stead of minimizeing the torque, the torque curve can be compared with a user defined profile as a reference.

The goal for optimization can be the minimization or maximization of a variety of properties (peak, RMS, average, …) or the difference between the actual and the target behaviour of a mechanism, such as:

• Trajectory of a node (with of without prescribed timing)
• Any motion or force quantity (as function of time or another quantity)

SAM seeks the optimum by modifying the following properties within user-defined ranges:

• geometry of mechanism
• element properties, such mass, spring constant, transmission ratio and mass position

SAM offers two optimization process modes:

• fully automated, SAM builds the best solution
• manual, the user can observe separate intermediate solutions

SAM uses a combination of a pure Monte-Carlo technique and an evolutionary algorithm, which makes a good deal between performance and perfect convergation. The video section of this website shows clear examples of optimization.