Digital Tool Chain for Lightweight-optimized Design of High-speed, Planar Mechanisms. This contribution presents the idea of a digital tool chain that combines the methods of mechanics synthesis, load analysis and structural optimization in a model-based approach and thus enables the development of dynamically more powerful and resource-efficient planar mechanisms in a significantly shorter development time.

Design of a strain wave gearing Harmonic Drives are uniformly high-reduction, coaxial gearboxes in which a flexible, elastically deformed gear is installed. They are used in applications where gears with high accuracy and stiffness, combined with low weight and installation space, are required. The following article outlines a softwarebased approach for designing these gearboxes, which involves generating the conjugate gearing of the gear components based on their kinematics.

Does AI help us with mechanism design? For decades, knowledge was stored in books, articles, illustrative models and passed on in the form of lectures and training courses by experts. Electronic media are now increasingly being used. However, in addition to pure storage, retrievability, processing and communication are also becoming increasingly important. This article attempts to provide an overview of the tasks, methods and current status of knowledge representation in the field of mechanism design and to identify the areas in which engineers could make a contribution.

Automatic Construction of a Four-Bar Linkage for a Folding Knife using the SG-Library The following article will show how the automatic design functions of the Matlab library SG-Library can be used to design and construct a four-bar linkage. A folding pocket knife is used as an application example. The starting point for the automatic design is the desired 2D contour of the handle shell and the 2D blade contour. These two contours are necessary to find suitable frame points on the handle scales and pivot points on the blade. Two poses are also specified for the blade, which the four-bar linkage should achieve exactly. Finally, the function is given an area that the blade contour must not touch in order to limit the solution space and ensure the safety of the user’s fingers. The software now grids the solution space and calculates all possible combinations and filters them for their suitability for the application. The user can then view animations of the solutions and select their preferred solution. As not all components of the four-bar linkage can work in the same plane, the layering of the components is defined in the next step. Now all components can be designed collision-free and the components can be saved as STL files. Finally, this mechanical design can be optimized for the application and the manufacturing process and installed in the handle scales of the knife.

Automatic Human Following and Gesture Control for a Mobile Robot using Vision-Based Human Pose Estimation The complexity of robot control and operation is often an obstacle to the widespread use of robots in everyday life. This paper presents intuitive control methods for a mobile robot, such as automatic human following and gesture control using vision-based human pose estimation. The determination of the user's position relative to the robot using pose estimation is derived from geometric relationships. This work also describes the training of a custom pose classifier for gesture control.

Four Ways to Ball’s Point. Discussing the curvature of a point on the moving plane, the circlepoint- curve is derived via inflection circle and the equation of Euler- Savary. Ball’s point, which is of high practical importance in mechanism design, lies at the point of intersection of circle-point-curve and inflection circle. There are three more ways to determine Ball’s point, which are presented briefly in an illustrative mechanism example. Symplectic geometry in vector space ℝ 2 is used for the derivation as a new innovative approach.

Investigation of methods for the synthesis of pick-and-place motions. This article examines methods for the synthesis of motions for pick-and-place tasks. Those tasks are increasingly encountered in processing machines. Depending on the application, different aspects on the motion design are required. Consequently, there are various approaches to the synthesis of a pick-and-place motion. Based on a specific application and a motion plan, motion designs are calculated using the various methods. These are assessed and categorised using various criteria.

Double-S-Profiles for motion tasks in VDI 2143 So-called Double-S-Profiles allow to realize maximum values for velocity, acceleration and jerk over a time interval thus avoiding higher maximum values for these quantities. They have been included in the new edition of the VDI Guideline 2143 for specific motion tasks (rest-in-rest, constant velocity in constant velocity). In this contribution, it is shown how equations for the remaining motion tasks can be developed and how one can stochastically or interactively generate motion functions with a good mixture of characteristic values.

Parameter study for the targeted reconfiguration of compliant mechanisms In their finished state, compliant mechanisms have optimal but unchangeable properties for their application. Targeted reconfiguration during their use would make it possible to open up new areas of application. For this reason, initial parameter studies were carried out to show the effect of targeted continuous reconfiguration on the natural frequencies of compliant mechanisms.

The Software Mechanism Developer – now available for Education and Industry. The Institute of Mechanism Theory, Machine Dynamics and Robotics of RWTH Aachen University has been developing the Mechanism Developer (MechDev) software for the interactive design and analysis of planar transmissions for some time [1-2] and regularly publishes its current progress [3-5]. This software is now generally available to the public. MechDev is recommended for educational purposes as well as for industrial applications. The core features of the software constitute a powerful toolkit for the kinematic and kinetostatic analysis of planar linkages, which is constantly being improved on.

Transversely symmetrical hinges in the CoMSys calculation tool A further development of the calculation tool CoMSys [1] for the analysis and optimization of compliant mechanisms is presented. Based on the theory of large deformations of rod-like structures, CoMSys is an efficient tool for calculating the deformation of compliant mechanisms. In addition to the currently implemented fully symmetric hinges, transversely symmetric hinges are also to be implemented. These are integrated into the user interface using previously described methods [2].

Review of IKBT and application with Blender – a method for generating the analytical IK of serial robots The calculation of the inverse kinematics (IK) together with a graphical representation of the kinematic system forms a basis for the design, simulation and control of robots. The advantageous, analytical solution of the IK of industrial robots is known in literature, but Zhang and Hannaford show another approach for automatically generated, compact, analytical solutions with the IKBT. This article discusses the IKBT and compares it to other approaches. Furthermore, it is shown how the IKBT can be used together with Blender for kinematic analysis within system engineering.

Design of a mechanical linkage for the continuous height adjustment of an agricultural high clearance tractor Biological plant protection can often only be used effectively in agriculture if the crops to be protected have already grown high. In this setting, we have developed and built a prototype of a high clearance tractor. Its unique feature are four planar linkages, which allow for a continuous height adjustment of the individual stilts using hydraulic cylinders.

Development of a precision wire feeder for small diameter wire Pulsed laser beam welding of small assemblies often involves the addition of a wire-shaped filler material to increase the melt. The existing automated wire feeding systems fail with wire diameters below 0,3 mm and wire feeding is only possible manually. This article describes the development process of a wire feed system based on a belt drive that overcomes the limitations of the state of the art. The development of the solution concept up to the first functional prototype is presented, highlighting key challenges and solutions.

Generation of polygon profiles for shaft-hub connections Polygon profiles are used as form-fit shaft-hub connections. The geometry of the special polygon profiles P3G and P4C is defined in the German industrial standards DIN 32711-1 and DIN 32712-2. Historically, polygon profiles were manufactured on special machine tools. Based on the definition of the profiles, several kinematic generation variants are derived and discussed in this article, whereby known variants arise in particular. Finally, the CNC manufacturing of polygon profiles is briefly discussed for comparison.

Design of a monolithic positioning mechanism as a 5-joint with ejection mechanism for pipette tips A monolithic mechanism for automated liquid handling in cell culture is presented. The mechanism uses solid-state joints to eliminate abrasion and potential sources of contamination. It is designed as a five-bar linkage with two degrees of freedom for horizontal positioning of the pipette tip. A further degree of freedom is used to switch between the aspirating and dispensing pipette and to eject the pipette tips. The entire mechanism is designed so that it does not contain any motors located above the cell cultures, which further reduces the risk of contamination. The mechanism is implemented in an automatic pipetting machine.

Design of topology-optimized compliant legs for quadruped robots Robotic legs are an important component of the quadruped robot for achieving different motion gaits. Although the conventional rigid-linkbased legs can generally perform robust motions, they still have the issues with poor sealing when operating in complex and liquid terrains. To cope with this problem, fully compliant legs with monolithic structure have been introduced in recent years to improve the system compactness and structural compliance of quadruped robots. In this work, we present a topology-optimization-based method to achieve efficient design of compliant robotic legs. In order to balance the structural stiffness and bending flexibility of the realized leg, a multi-objective optimization algorithm is utilized. A series of design cases are presented to illustrate the design principle and analytical procedure of the proposed method. In addition, experimental evaluation is also performed, and the results have demonstrated that, a quadruped robot with the optimized legs can successfully achieve stable and continuous straight-line walking motions.

Validation of an Energy-efficient Drive Method for Cam Mechanisms on a Test Bench Due to the climate change, changing legislation and increased demands on energy efficiency, the industry is constantly looking for ways to minimise costs. Not only in the packaging industry, but also in the fields of handling and forming technology, non-uniformly translating mechanisms are used to generate certain motions. For several decades now, there have been attempts to operate such mechanisms in a more energy-efficient manner, with so-called Eigenmotion being a promising approach. Practical implementation in industry has become possible with the development of servo motors, as they can reproduce the Eigenmotion with high precision. The combination of non-uniformly translating mechanisms and a variable drive speed has been the subject of research ever since. This article presents a comparison and discussion of the measurement results of a cam mechanism driven at a constant angular velocity and an energy-efficient cam mechanism.

Use of Depth Cameras for Hand Intuitive Control of Linear Axes in Assembly Cells Intuitive hand or head motion based controls enhance the flexibility and adaptability of partially automated assembly processes by improving human- machine interaction. This paper discusses the control of an assembly cell with three linear axes and one rotary axis, all driven by servo motors, using motion tracking. A delta robot is attached to the fourth axis of the cell. A depth camera or VR controller tracks the hand position, and VR headset tracks the head position to operate the end effector via a programmable logic controller (PLC).

2D “TenSens” sensor for simultaneous force/torque measurement This paper presents a 2D force/torque sensor, which uses an optical fiber sensor to determine external forces in a plane and moments in a normal direction to that plane. The sensor concept does not require a deformation body due to the multifunctional use of a prestressed optical fiber sensor acting as both a measuring device and a structural component, and thus offers potential for lightweighting as well as the reduction of manufacturing and model complexity.