@@ -72,7 +72,7 @@ Robots are very essential to some of the today's modern industry because they he
Here comes the concept for cobots. They are robots which are built to perform alongside humans and this too safely. The word cobot is derived from so called collaborative robots which are kind of robots made to perform alongside human presence in a commonly used area. Most times they are in very close proximity working alongside each other but the design decisions and multi level safety which range from soft built to auto-emergency stop features ensure they can work very reliably alongside each other.\\
Cobots are evolved version of traditional robots, and traditional robots are only meant to perform without safety features on both levels comprising physical safety as well as software built detection features giving intelligence to robot. Thus these are the factors which differentiate a robot from a cobot.
These features are built in cobots but traditional robots do not have them. Cobotic safety relies on lightweight construction materials, curved edges on control surfaces and no sharp edges but only rounded curves, and comes with inherent limitation of speed and force when working along human presence.
These features are built in cobots but traditional robots do not have them. Cobotic safety relies on lightweight construction materials, curved edges on control surfaces and no sharp edges but only rounded curves, and comes with inherent limitation of speed and force when working along human presence.\\
Cobots are built for an industry setting workspace and have different hardware and software to run them along with above mentioned features of safety. Some of essential features of cobots are -
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@@ -130,13 +130,13 @@ A human worker maybe crushed with arm motion of the robot or a human may get tra
The above listed hazards are minimized by: \\
– enforcing strictly pre-mapped environment and space for the cell of cobot\\
– enforcing strictly pre-mapped environment and space for the cell of cobot
– strictly followed operational routine\\
– strictly followed operational routine
– authorization of machine operators, maintenance workers and programmers\\
– authorization of machine operators, maintenance workers and programmers
– speed limitation on movement of control surfaces in presence of human\\
– speed limitation on movement of control surfaces in presence of human
@@ -10,7 +10,7 @@ The real life problem scenario can be described as follows. Robot is expected to
The use case can be understood by seeing a scenario where we can train the robot in a laboratory / ideal conditions and give a working functionality to it by giving a design which shows how to perform a task which robot can use to work accordingly and this is known as application model implementation. This robot has a teaching mode where we can set a series of poses and grasp actions manually which can train the robot to perform a task according to a plan and this can be done repetitively by the robot later in scenario 2 which is real world and has added conditions of realism.\\
For this ,complex condition are added to application model about how to respond when it detects a human in proximity and obstacles in trajectory paths and in addition this real world simulation adds real world conditions like adding torque to joints as is in real world to see if arm can for example really life an object.
For this ,complex condition are added to application model about how to respond when it detects a human in proximity and obstacles in trajectory paths and in addition this real world simulation adds real world conditions like adding torque to joints as is in real world to see if arm can for example really life an object.\\
In scenario one the architecture of robot`s world model is already known and has thus been used ,its teaching capability to train it to move to a coordinate position and then start a trajectory for instance at position X to move a position close to an object that is needed to be say picked up and then it can use its gripper to pickup the object and again move arm to another desired location where it want to drop the object and there it releases the gripper to put that object down and thus completing the task at position Y. This is part of application model as described before.\\
@@ -8,9 +8,8 @@ A robot is present and then one or more humans are in proximity along with one o
To start with a fictitious plan, the robot uses a motion planner to move arm and pickup an object and then move again according to already planned motion trajectory and release the object at desired location thus completing the task. So far this plan is only about doing the task but sans the idea of any kind of obstacle or human which can cause a hindrance to already planned motion which would thus require an alteration to planned trajectory right at that time instant when sensors detect obstacle and move around the obstacle to reach a coordinate position around the obstacle to a point in pre decided motion plan and then continue motion from there onwards. After the motion planning part a simulation software is used to see if motion trajectory correction is feasible and working in real life and to see how successful it can be~\cite{4}.\\
To demonstrate such a concept a world is shown which contains the robot Panda, its arm, obstacle object which can be a ball or cube box and human beings. The thesis work designs a world model , an application model, and safety model for which different diagram forms are used and they are discussed further.
To demonstrate such a concept a world is shown which contains the robot Panda, its arm, obstacle object which can be a ball or cube box and human beings. The thesis work designs a world model , an application model, and safety model for which different diagram forms are used and they are discussed further.\\
\newpage
\section{Modeling - Explaining Choice of Design Depictions}
Thesis work tries to find correct diagram depictions for all three intended diagrams which are world model, application model and lastly safety model.
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@@ -19,7 +18,7 @@ Thesis work tries to find correct diagram depictions for all three intended diag
\item WORLD MODEL\\
Unified Modelling Language UML For class and object diagrams for world model using the web tool Online Visual Paradigm is shown in Fig 4.1 and Fig 4.2 is displayed above.The UML class model is used to derive the objects and depict in the UML object model.\cite{17}
Unified Modelling Language UML For class and object diagrams for world model using the web tool Online Visual Paradigm is shown in Fig 4.1 and Fig 4.2 is displayed above.The UML class model is used to derive the objects and depict in the UML object model~\cite{17}.\\
\begin{figure}
\centering
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@@ -41,7 +40,7 @@ This world model class diagram has been designed to contain ten classes. The mai
\item APPLICATION MODEL – BUSINESS PROCESS MODELING NOTATION USING MODELIO \\
Business Process Modelling Notation(BPMN) For application model using Modelio was chosen for application model. Depicted in Figure 4.3~\cite{18}\\
Business Process Modelling Notation(BPMN) For application model using Modelio was chosen for application model. Depicted in Figure 4.3~\cite{18}.\\
This was found to be good choice to show application process as this shows cells which depict each component in the world model diagram and then allowed to depict the relationship and connection between their components and showing their flow which have a comprehensive and logical consistency among cells. It uses start and end event states and then “if” conditions as well as flow lines with process events and intermediate events to other components of world diagram to construct application model. In detail components are described as - \\
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@@ -54,7 +53,6 @@ Events, Activities and Gateways. Objects are connected using Sequence Flows , Me
\label{fig:app}
\end{figure}
\newpage
\item SAFETY MODEL DEPICTION USING UML STATE CHART \\
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@@ -74,12 +72,10 @@ In Fig.4.4 The start and end events denote the process starting and end. The tra
\label{fig:3-figure4-1}
\end{figure}
Fig.4.5 There has been extensive work done to incorporate safety into real world robots particularly from Sami Haddadin. It has built the robot with technology ranging from making the robot understanding safety i.e by making them softer in approach when operating to preventing any physical collision by embedding injury knowledge into controls. The robot surfaces are made softer and force reduced when in proximity to collision objects up to a level where the robot can affirmatively detect the kind of object in proximity and classify that as a serious or not so seriously unsafe object. Extensive testing has been done on injuring pig skin~\cite{19}.
Fig.4.5 There has been extensive work done to incorporate safety into real world robots particularly from Sami Haddadin. It has built the robot with technology ranging from making the robot understanding safety i.e by making them softer in approach when operating to preventing any physical collision by embedding injury knowledge into controls. The robot surfaces are made softer and force reduced when in proximity to collision objects up to a level where the robot can affirmatively detect the kind of object in proximity and classify that as a serious or not so seriously unsafe object. Extensive testing has been done on injuring pig skin~\cite{19}.\\
\end{enumerate}
\newpage
\section{Tools Used }
\subsection{Setup Environment Using ROS To Run Services ,Motion Planning In RVIZ Using MOVEIT ,GAZEBO For Simulations}
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@@ -97,6 +93,6 @@ RviZ/MoveIT motion planner was used for motion planning as this software lets us
Gazebo simulator was used which is real world simulator to run the motion plan from MoveIT. This lets us see if the real world simulation is possible for the conceived motion plan and trajectory. Gazebo also has additional features which can add real time parameters to its simulation like altering torque of joints to see how robot reacts in real world.
