Field of the Invention
The present invention relates to a dynamics calculation method, a program and a recording medium used for a mechanism analysis simulation or the like. The present invention relates, more particularly, to a dynamics calculation method and a non-transitory recording medium that records a program suitable for use in dynamics calculation of a body made up of components connected through a movable axis and components connected through a fixed axis.
Description of the Related Art
Conventionally, when designing a machine product provided with an operation mechanism, mechanism analysis simulations are performed using a calculating machine such as a computer for confirming operation of the product in advance. In a mechanism analysis simulation, a movement of a whole product is simulated by performing dynamics calculation according to forward dynamics based on a dynamics model (also referred to as “simulation model”). A designer of the product (hereinafter referred to as “user”) can analyze not only operation of the product but also interference between components included in the product and a force applied to each component by performing a mechanism analysis simulation.
In the case of a multi-axis robot constructed by connecting many components through a movable axis or fixed axis, displacement/speed/acceleration of each component varies depending on, for example, torque input to each axis, and attitude in a time sequence is determined. However, since an actual movement of the multi-axis robot is affected by gravity/inertia or the like, it is difficult for a user to design a product by predicting such an affected movement. Thus, a link mechanism analysis apparatus and a link mechanism indirect data calculation apparatus are being proposed which perform simulations to confirm operation of a multi-axis robot having a link mechanism and confirm interference with a peripheral environment (Japanese Patent Publication No. 3361007). This apparatus simulates an overall movement by performing dynamics calculation using an amount of drive or drive force as an input parameter regarding a link mechanism.
When performing a simulation using a computer, a user needs to construct a simulation model in advance by connecting many components through a movable axis or a fixed axis on a computer. A simulation model having a high degree of reusability is used when performing a simulation of a product such as a multi-axis robot system in particular in which replacement of components, change of component positions, change of a combination of components or the like frequently takes place. This model is convenient because components making up the multi-axis robot system are subdivided in advance and the user can thereby easily construct a simulation model in many patterns by only changing a combination of components as required.
However, conventionally, the more the components are subdivided to increase the degree of reusability, the more noticeably the convenience as a simulation deteriorates. That is, when the components are subdivided, the number of components combined to construct a simulation model increases. Dynamics calculation has a feature that the amount of calculation increases according to the number of components. For this reason, when a simulation model formulated by combining many components is used, the processing load placed on dynamics calculation increases, consequently increasing a time required from the start of a simulation to the result output, resulting in poor usability.
The present invention has been implemented in view of the above-described problems and it is an object of the present invention to provide a dynamics calculation method, a program and a recording medium capable of performing high accuracy dynamics calculation without increasing a processing load when performing dynamics calculation based on a dynamics model formulated by combining many components.