Minimum Set Of Inertial Parameters Research Articles

Base parameters that can be identified from measured values and a control scheme for planer Torque-unit manipulator

A base parameter set which is defined to be a minimum set of inertial parameters that can determine dynamic model uniquely is shown for Torque-unit Manipulator (TUM) which has been proposed as a new design concept of manipulator. The elements of the base parameter set are also the parameters that can be identified independently from motion data and input data, i.e., measured values. The base parameters play very important role for dynamic modelling of manipulators such as model based control and simulation of the manipulator motion. The base parameters are given completely in closed from of linear combinations of the link inertial parameters. Also, a control strategy for all state variables of TUM is given by using the base parameters.

Determination of the symbolic base inertial parameters of planar mechanisms

Abstract The inertial information of a planar mechanical system is characterised using 4 inertial parameters per solid. Due to the kinematic constraints, this parametrisation turns out be redundant. In order to reduce the computational cost of the model and make it possible to estimate its inertial parameters, the model is usually written in terms of a minimum set of inertial parameters called base inertial parameters . These parameters completely determine the dynamics of motion (kinetics) of a mechanism and, since their contributions are independent to each other, their actual values can be estimated experimentally. The base inertial parameters expressions can be written as a linear combination of the inertial parameters and determining their symbolic expressions provides a deeper insight into their physical meaning. This paper presents a new algorithm to determine the symbolic expressions of the base inertial parameters of planar mechanisms. The approach is based on a very well known numerical method to obtain the base inertial parameters and on the fact that these parameters belong to a class of functions that lets us search for symbolic expressions matching with them. Since the symbolic expressions are a function of the geometric constants of the system, the presented algorithm constitutes a very valuable tool in design optimisation and it is also very interesting in dynamic parameter estimation, model reduction and other fields.

Base parameters for manipulators with a planar parallelogram link mechanism

A base parameter set which is defined to be a minimum set of inertial parameters whose values can determine the dynamic model of a kinematic chain uniquely has been shown in complete closed-form for manipulators with a planar parallelogram link mechanism. The exact number of the base parameters has also been shown. A base parameter set plays a fundamentally important role to identify the dynamic model and to control and simulate the manipulator motion. The results would cover most of the commercially available industrial manipulators with closed chain mechanisms.

Comments on "Direct calculation of minimum set of inertial parameters of serial robots"

The paper presented by Gautier and Khalil (see ibid., vol.6, no.3, p.368-73, 1990) gives a direct and efficient method of calculating most of the minimum inertial parameters of serial robots. Some parameters concerning the translational links between the first two rotational joints that are not parallel need particular calculation; partial results concerning the case where these links are either perpendicular or parallel are given in the above paper. This correspondence presents a direct solution of this particular case, such that all the minimum inertial parameters can be obtained directly without calculating the energy or the dynamic model of any link. >

Minimal Parametrization of Robot Dynamic Models*

This paper presents systematic rules for determining the minimum set of inertial parameters that are relevant for the dynamic model of serial and tree-like manipulators. In particular, it is shown, starting from the barycentric definition of inertial parameters, that a limited number of additional rules are necessary to obtain this minimum set. Moreover, the value of these parameters can be identified experimentally either from the dynamic model or from a reaction model that relates the robot motion to the reaction forces and torques transmitted to its bedplate.

Numerical calculation of the base inertial parameters of robots

AbstractThis article presents a new approach to the problem of determining the minimum set of inertial parameters of robots. The calculation is based on numerical QR and SVD factorizations and on the scaling procedure of matrices. It proceeds in three steps: eliminate standard inertial parameters which have no effect on the dynamic model, determine the number of base parameters, and determine a set of base parameters by regrouping some standard parameters to some others in linear relations. Different models, linear in the inertial parameters are used: a complete dynamic model, a simplified dynamic model, and an energy model. The method is general, it can be applied to open loop, or graph‐structured robots. The algorithms are easy to implement. An application for the PUMA 560 robot is given.

Minimum inertial parameters of robots with parallelogram closed loops

A symbolic method to determine the minimum set of inertial parameters of robots containing parallelogram closed loops is presented. The solution is obtained by determining the minimum inertial parameters of an equivalent tree structure. Then, the constraint equations of the closed loops are taken into account to get the global minimum inertial parameters. Direct general relations are obtained for the two steps.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Direct calculation of minimum set of inertial parameters of serial robots

The determination of the minimum set of inertial parameters of robots contributes to the reduction of the computational cost of the dynamic models and simplifies the identification of the inertial parameters. These parameters can be obtained from the classical inertial parameters by eliminating those that have no effect on the dynamic model and by regrouping some others. A direct method is presented for determining the minimum set of inertial parameters of serial robots. The method permits determination of most of the regrouped parameters by means of closed-form relations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Base parameters of manipulator dynamic models

A base parameter set as a minimum set of inertial parameters whose values can determine a dynamic model uniquely is investigated for a general parallel and perpendicular manipulator with rotational joints only. The notion of a base parameter is useful for an efficient and accurate identification of the manipulator dynamic model. A set of inertial parameters described in linear combinations of link parameters directly and completely in closed form is given and proved to constitute a base parameter set. It can be derived from this that the minimum number of inertial parameters whose values can determine the dynamic model is 7N-4 beta /sub 1/ (7N-4 beta /sub 2/-2 if the first joint axis parallel to the gravity vector), where N is the number of links in the manipulator, and beta /sub 1/ is the number of links connected by joints whose axes are always parallel to the first joint axis. After defining the base parameter, it is also shown that any base parameter set can be obtained from one base parameter set by a nonsingular linear transformation. The method adopted has the potential advantage of determining the relations between base parameters and manipulator motions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The use of the generalized links to determine the minimum inertial parameters of robots

AbstractThis article presents a new method to determine the minimum set of inertial parameters of robots. The method permits to determine most of the regrouped parameters by means of recursive closed form relations. It is based on the use of a new expression for the kinetic and potential energy of the robot as function of the inertial parameters of the generalized links. The demonstration is seen to be easier than the previous methods and gives a clear idea about the physical meaning of the regrouped parameters.