A Brief History of Industrial Robotics in the 20th Century

Industrial robotics is a branch of robotics that gained paramount importance in the last century. The presence of robots totally revolutionized the industrial environment in just a few decades. In this paper, a brief history of industrial robotics in the 20th century will be presented, and a proposal for classifying the evolution of industrial robots into four generations is set forward. The characteristics of the robots belonging to each generation are mentioned, and the evolution of their features is described. The most significant milestones of the history of industrial robots, from the 1950\u2019s to the end of the century, are mentioned, together with a description of the most representative industrial robots that were designed and manufactured in those decades

3-D ERLS based dynamic formulation for flexible-link robots: theoretical and numerical comparison between the Finite Element Method and the Component Mode Synthesis approaches

The industrial demand for high-performance and low energy consume has highlighted the need to develop lightweight manipulators and robots. However, their design and control result more difficult with respect to rigid-link robotic systems mainly due to the structural flexibility of the arms. To this end, the Equivalent Rigid-Link System (ERLS) approach for 3-D flexible link robots has been developed and, in this work, is considered in its recent developments. In particular, two recently published 3-D Equivalent Rigid-Link System formulations are discussed and compared by means of numerical simulations to highlight their strengths and possible weaknesses. The former deals with the Equivalent Rigid-Link System concept extension to spatial manipulators and robots through a Finite Element Method approach (ERLS-FEM), whereas the latter reformulates the model through a Component Mode Synthesis technique (ERLS-CMS). After the definition and discussion of the kinematic and dynamic equations, which account for the coupling between rigid-body and flexible-body motions, an extensive comparison is made. A benchmark manipulator is implemented and the formulations numerically compared in terms of accuracy and computational load under different input conditions

Modelling and control of mechatronic and robotic systems

3noopenopenGasparetto A.; Seriani S.; Scalera L.Gasparetto, A.; Seriani, S.; Scalera, L

Development of n-DoF preloaded structures for impact mitigation in cobots

A core issue in collaborative robotics is that of impact mitigation, especially when collisions happen with operators. Passively compliant structures can be used as the frame of the cobot, although usually they are implemented by means of a single DoF. However, n-DoF preloaded structures offer a number of advantages, in terms of flexibility in designing their behavior. In this work we propose a comprehensive framework for classifying n-DoF preloaded structures, including 1-, 2-, and 3-dimensional arrays. Also, we study the implications of the peculiar behavior of these structures - which present sharp stiff-to-compliant transitions at design-determined load thresholds - on impact mitigation. To this regard, an analytical n-DoF dynamic model was developed and numerically implemented. A prototype of a 10-DoF structure was tested under static and impact loads, showing a very good agreement with the model. Future developments will see the application of n-DoF preloaded structures to impact-mitigation on cobots and in the field of mobile robots, as well as to the field of novel architected materials

Cable-Based Robotic Crane (CBRC): Design and Implementation of Overhead Traveling Cranes Based on Variable Radius Drums

In this paper, we present a new family of overhead traveling cranes based on variable radius drums (VRDs), called cable-based robotic cranes (CBRCs). A VRD is characterized by the variation of the spool radius along its profile. This kind of device is used, in this context, for the development of a cable-robot, which can support and move a load through a planar working area with just two degrees of freedom. First we present the kinematic analysis and the synthesis of the geometry of a VRD profile. Then, the schema of a bidimensional horizontal moving mechanism, based on the VRD theory, and an experimental prototype of a three-dimensional CBRC are presented. The features of this wire-based overhead crane and an analysis of cables tensions are discussed. Finally, the performance of this mechanism is evaluated, demonstrating a deviation between the end-effector and the nominal planar surface of less than 1% throughout the whole working area

Comparison of Model Order Reduction Techniques for Flexible Multibody Dynamics using an Equivalent Rigid-Link System Approach

In this paper we present a comparison of different model order reduction techniques for flexible multibody dynamics. In particular, we adopt a formulation based on a Equivalent Rigid-Link System (ERLS). This approach is suitable in the case of large displacements and small elastic deformations and it allows the kinematic equations of motion to be decoupled from the compatibility equations of the displacements at the joints. The ERLS approach, recently extended through a modal formulation, is here implemented in combination with different reduction techniques, i.e. Craig- Bampton, Interior Mode Ranking (IMR), Guyan, Least Square Model Reduction (LSMR) and Mode Displacement Method (MDM). In order to assess the advantages and disadvantages of the different methodologies, these techniques are applied to a benchmark mechanism under different input conditions, i.e. gravitational force and step torque input. The accuracy of each reduced model is numerically evaluated through the comparison of computational time, the behaviour in frequency domain and by means of vector correlation methods, i.e. the Modal Assurance Criterion (MAC), the Cross-Orthogonality (CO) and the Normalized Cross-Orthogonality (NCO)

Energetic analysis of industrial robots for pick-and-place operations

none4restrictedF. Vidussi, P. Boscariol, L. Scalera, A. GasparettoVidussi, F.; Boscariol, P.; Scalera, L.; Gasparetto, A

Enhancing Energy Efficiency of a 4-DOF Parallel Robot Through Task-Related Analysis

Enhancing energy efficiency is one of the main challenges of today\u2019s industrial robotics and manufacturing technology. In this paper a task-related analysis of the energetic performance of a 4-DOF industrial parallel robot is presented, and the optimal location of a predefined task with respect to the robot workspace is investigated. An optimal position of the task relative to the robot can indeed reduce the actuators\u2019 effort and the energy consumption required to complete the considered operation. The dynamic and electro-mechanical models of the manipulators are developed and implemented to estimate the energy consumption of a parametrized motion with trapezoidal speed profile, i.e., a pick-and-place operation. Numerical results provide energy consumption maps that can be adopted to place the starting and ending points of the task in the more energy-efficient location within the robot workspace

Natural Motion for Energy Saving in Robotic and Mechatronic Systems

Energy saving in robotic and mechatronic systems is becoming an evermore important topic in both industry and academia. One strategy to reduce the energy consumption, especially for cyclic tasks, is exploiting natural motion. We define natural motion as the system response caused by the conversion of potential elastic energy into kinetic energy. This motion can be both a forced response assisted by a motor or a free response. The application of the natural motion concepts allows for energy saving in tasks characterized by repetitive or cyclic motion. This review paper proposes a classification of several approaches to natural motion, starting from the compliant elements and the actuators needed for its implementation. Then several approaches to natural motion are discussed based on the trajectory followed by the system, providing useful information to the researchers dealing with natural motion