20 accepted papers
Research on human-friendly robots focuses on safety through software and hardware. Hardware-based safety offers a significant advantage over software-based safety if an accurate hardware model is integrated into the solution. Design of elastic and off-joint actuation has established safety by hardwa
In collaborative robotics, the safety of humans interacting with cobots is crucial. There is a need for collaborative robots that can move quickly while still being safe. This paper introduces the use of a kinematically redundant actuator in impedance control mode to reduce collision forces, aiming
Redundant actuators enable to distribute power among two motors, which can be selected optimally in terms of efficiency. We propose a methodology that finds effective combinations of motors and gearboxes for a dynamic load, taking into account the constraints, inertia, and efficiency of each compone
Gravity compensators are passive devices that can lower the energy consumption of lifting systems by reducing the force/torque required from human users or actuators. This letter presents a prismatic gravity compensator for cranes, gantry, and other lifting systems. It is capable of statically balan
New challenges arise when investigating the use of active prostheses for lower limb replacement, such as high motor power requirements, leading to increased weight and reduced autonomy. Series and parallel elasticity are often explored to reduce the necessary motor power but often the effect on the…
Research towards (compliant) actuators, especially redundant ones like the Series Parallel Elastic Actuator (SPEA), has led to the development of drive trains, which have demonstrated to increase efficiency, torque-to-mass-ratio, power-to-mass ratio, etc. In the field of robotics such drive trains c…
In this letter, we present the kinematically redundant series elastic dual-motor actuator (SEDMA). It consists of two motors, coupled to a series spring through a planetary differential. The redundant degree of freedom of this system can be exploited to optimize a specific aspect of the actuation ta
Driven by the desire of amputees to reduce their physical shortcomings, prosthetic feet evolved from passive to propulsive bionic feet, actuated by different types of compliant actuators to provide the push-off power and with the advantage of reducing the motor power requirements. The two-latest in-
On compliant robotic systems, modularity is recently adopted for the ease of up- and downscaling and the possibility to downgrade the costs, by moving towards the combination of standard units instead of custom designs. However, modularity on the actuator level itself lacks more thorough evaluation.
Pneumatic muscles are mostly constructed out of flexible membranes and are implemented in a wide range of robotic applications. In these soft materials, perforations are often caused by overpressuring of the muscles and wear. In many cases, this leads to limited numbers of actuation cycles. In this
The control of mechatronic systems can often be enhanced if realtime information on the derivatives of a signal is available. These derivatives are not always measurable by sensors and should be estimated. Simple numerical derivatives cannot be applied, due to noise on the measured signals. Several
Despite significant advancements in the field of wearable robots (WRs), commercial WRs still use traditional direct-drive actuation units to power their joints. On the other hand, in research prototypes compliant actuators are increasingly being used to more adequately address the issues of safety,…
Collaborative robots, the so-called cobots, that work together with the human, are becoming more and more popular in the industrial world. An example of an application where these robots are useful is the assembly task. In this case, the human and the robot complement each other. On one side, the hu…
On novel actuator research in the field of cellular muscle-inspired actuators, skeletal muscles are often used as inspiration due to their modular and compact design and seemingly effortless control. Amongst others, the remaining challenges to tackle are robust designs, energy consumption minimizati…
The control of compliant joint manipulators is challenging for two reasons. First, the elastic elements of the compliant actuators can store an important amount of energy that can be potentially dangerous and needs therefore to be controlled. Second, the compliance introduces nonlinearities and unce
Modern actuation schematics become increasingly ingenious by deploying springs and locking mechanisms in series and/or parallel. Many of these solutions are, however, tailored for a specific application and a general schematic that allows for drastic energy reduction remains a challenge. We have dev
In recent years, many works have appeared, which present novel mechanical designs, control strategies, or trajectory planning algorithms for improved energy efficiency. The actuator model is an essential part of these works, since the optimization of energy consumption strongly depends of the accura
Series-Parallel Elastic Actuators (SPEA) enable variable recruitment of parallel springs and variable load cancellation. In previous work, we validated a MACCEPA-based SPEA prototype with a self-closing intermittent mechanism, to reduce motor load and improve energy efficiency. However, the mechanis…
Last 15 years, a wide range of self-healing (SH) materials has been developed and recently these materials are increasingly used in applications in multiple fields, like the automotive industry and aerospace. However, so far this material technology is not yet explored in robotics. The introduction…
The Mechanically Adjustable Compliance and Controllable Equilibrium Position Actuator (MACCEPA) is a Variable Stiffness Actuator (VSA) where both equilibrium position and stiffness of the actuator can be controlled independently. It uses only one linear spring and has a simple design but its compact…