This paper proposes a pose estimation approach of an industrial six-degree-of-freedom robot without the need of externally placed sensors. An RGB-D camera that is placed at the robots end-effector is combined with a SLAM algorithm to act as a sensor system. The presented system based on the novel integration approach is evaluated by performing test trajectories and is capable of estimating the tool-center point with a standard deviation of 2.6 mm and performing a joint state estimation with a standard deviation of 13.6 mrad without any external sensor.

Depth-data-based sensor systems, such as depth cameras or LiDAR systems, are gaining popularity in the field of robotics, especially in human-robot collaboration. To avoid collisions with humans or external objects, object detection and tracking in the workspace is needed. This paper presents an integrated object cluster tracking and velocity estimation method that is purely based on depth data. Therefore, a tracking heuristic based on similarity and the velocity of the object is used to enable the tracking of external objects. To obtain the velocity, a Kalman filter utilizing a constant velocity model is implemented. For experimental verification, a case study comprising two objects moving within the robot workspace is designed. The experimental setup allows for the initial tracking a maximal trackable object velocity of 9 m s −1, and for already tracked objects a velocity deviation of 3.4 m s-1 to correctly track both repetitive and arbitrary motions of the test objects, and thus constitutes the proposed integrated object cluster tracking approach as a foundation for collision avoidance strategies in robotic tasks.

The measurement of external forces in Collaborative Robots (Cobots) is commonly realized by dedicated sensors in the joints. Since the use of these sensors is cost-intensive and reduces the stiffness of the manipulator, alternative approaches are needed. This paper presents a sensing principle for measuring external forces acting on a robot arm using a generalized momentum observer. The proposed approach does not require dedicated force/torque sensors and relies on measurements available in standard robot joints. The presented method estimates the external forces based on motor current measurement and joint torsion measurement. Both measurements are implemented and compared against a dynamometer in terms of accuracy. Depending on the joint, an RMS error within 2% to 4% of the dynamometer measurement can be achieved.

Today's markets are short-lived and volatile. The producing industry needs to be able to react fast and cost-effective to product and process changes. Following the trend of Industry 4.0, current automation systems are designed as Cyber-Physical Production System (CPPS), which main properties are the distribution of capabilities and strict modularization to enhance reuse of off-the-shelf automation components. The currently dominant Programmable Logic Controller programming standard IEC 61131 was conceived with mainly centralistic systems in mind, which limits its use for nowadays CPPS scenarios. Focusing on the software aspect, the contribution of this work is an enhanced hierarchic development approach for automation systems, which aims to decouple all hardware from the control flow logic of an automation system for combined IEC 61131 and IEC 61499 systems. Therefore, a migration path for IEC 61131 Function Blocks into the development model of the event-driven IEC 61499 is presented, and issues are discussed. Both approaches pay special attention to the reusability of software.

Automation system engineering becomes more complex, due to the trend toward more flexible, reconfigurable, and modular design approaches, like Industry 4.0. For the modeling and design of the according software, two standards are present: IEC 61131-3 and IEC 61499. In order to satisfy the requirements for modern, large scale, highly distributed applications while also supporting still existing legacy systems, the demand for a combined development framework arises, where the best of breed tool can be chosen for a given automation task. Considering that, the IEC 61499 model is extended to allow the dual development and execution of IEC 61131-3 programs, and enabling easy and correct interaction between the two paradigms. In order to verify the validity of the chosen approach, an IEC 61499 development tool and a runtime environment is modified to support IEC 61131-3. A sample application is implemented, which comprises a pure IEC 61131-3 part with a 1 ms cycle time, a pure IEC 61499 part, and a part with interaction between both subparts, in order to evaluate possible interference between the runtime parts. Experimental results show that no interference is occurring, and the chosen development approach allows the seamless integration of IEC 61131-3 and IEC 61499 in one combined development framework.

The IEC 61131-3 and IEC 61499 standards are currently used to implement automation systems. Although aspects as reuseability, execution models, and component-based design have been discussed and analyzed for both standards, the programming effort and complexity of implementation for typical tasks in industrial automation have not been compared so far. This work proposes two typical application classes of industrial automation systems and implements one concrete application for each class with IEC 61131-3 and IEC 61499, respectively. Both implementations are then evaluated via McCabe's Cyclomatic Complexity and Halstead software measures, providing an objective comparison on the implementations.