January 29, 2002
Basilio Bona: firstname.lastname@example.org
99-38 contract is relative to the third and last year of a
coordinate research project, whose goal is the construction of a flexible
robot arm prototype, equipped by a motor and integrated with an intelligent
control architecture, to study the various matters related to flexible
robots control. The carried out research dealt with both the mechanical
and control aspects, with the design and implementation of the control
electronics, and finally with the development of a complete simulator
of the plant. Graphical techniques have been studied also for 3D simulation,
to be used as an aid to the operator for a subsequent remote control
(teleoperation) of the robot arm.
During the first six months of the research activity, the flexible link prototype has been assembled, and a complete simulator has been developed in the Simulink environment (mainly by the DAUIN-TO and DIMEC-TO groups). An easy substitution of the flexible beam and/or the addition of a payload (possibly a second link, with its actuator) are allowed by construction. Electromagnetic proof mass dampers have then been studied and constructed by the DIMEC-TO group, to be alternatively used instead of the piezoelectric transducers currently employed. A devoted test rig has been constructed, to test their effectiveness before using them in the flexible link prototype.
From the control point of view, the DAUIN-TO group has studied different schemes for the control of the flexible link, by following the LQG, LTR and approaches, and tested them (even if presently only by simulation); previous studies about impact control have been extended and completed in collaboration with the DIA-RO3 group, also experimentally by using a test-bed that is available in the laboratories of Università di Roma Tre.
The DELEN-TO group has provided detailed specifications of a high-level co-design environment for programmable control systems, by using well-known languages both for the design environment, such as Matlab/Simulink, and for the hardware description, as VHDL. A detailed project of a DSP/PLD based control system has also been developed.
The DIA-RO3 unit has finally developed a 3D graphical simulator, to be used as an aid to the operator for the remote control of the manipulator, by employing the Internet network for the data transmission.
In the remainder of the this document, a detailed description of the research activity is provided by the single units that mainly dealt with the various aspects.
Coordinator Prof. Dante Del
The work carried on in the first six months, was essentially based on two main points:
- detailed specifications of a high-level co-design environment for programmable control systems
- detailed project of a DSP/PLD based control system
About the first point, we developed the specifications of a high-level design environment for hardware/software programmable platforms.
This choice was made concurrently with the design of a general purpose control system based on programmable logic devices (PLD) and commercial DSPs: this platform allows more flexibility than others (based on custom VLSI devices, original project) when used to implement programmable control architectures (classic and neuro-fuzzy).
The DSP/PLD board can also be used to test VLSI devices with good accuracy: in fact it is possible to download on programmable devices the same control architectures implemented on custom VLSI chips. This approach requires high level description tools and languages (VHDL for example) also for VLSI chip synthesis.
Coordinator Prof. Giancarlo Genta
The main research themes developed by Dipartimento di Meccanica of Politecnico di Torino during the first semester of the contract ASI n. ARS-99-38 concern the following subjects:
- Finite elements models of flexible links equipped with "active constrained layer dampers" (ACLD).
- Modal reduction techniques and integration of the centrifugal and Coriolis effects acting on the rotating arm into its FEM model.
- Design and construction of electromagnetic proof mass dampers.
- Design and construction of a test rig including a clamped beam of modular configuration with piezoelectric transducers and electromagnetic proof mass damper.
Fig. 1 : scheme of the finite element with ACLD
Fig. 2 : demonstrator
Fig. 3: flexible link with dynamic damper at the free end
Fig. 4 dynamic damper configuration
Fig. 5: dynamic characterization of the flexible link
Coordinator Prof. Antonio
The research activities of the Unit Roma Tre have been focused on the realization of a 3D graphical simulator, to be used as an aid to the operator for the remote control of a telemanipulator: the simulator thus realized, although it is at a beta release stage, utilizes the sensors data obtained from the robot encoder, the data obtained by computer simulations of an accurate model of the robot, and the data that can be obtained by analyzing the images of the working space captured by a webcam. The Internet network has been used for the data transmission.