12 results
(View BibTeX file of all listed publications)
2023
An Open-Source Modular Treadmill for Dynamic Force Measurement with Load Dependant Range Adjustment
Sarvestani, A., Ruppert, F., Badri-Spröwitz, A.
2023 (unpublished) Submitted
Ground reaction force sensing is one of the key
components of gait analysis in legged locomotion research. To
measure continuous force data during locomotion, we present a
novel compound instrumented treadmill design. The treadmill is
1.7 m long, with a natural frequency of 170 Hz and an adjustable
range that can be used for humans and small robots alike. Here,
we present the treadmill’s design methodology and characterize it
in its natural frequency, noise behavior and real-life performance.
Additionally, we apply an ISO 376 norm conform calibration
procedure for all spatial force directions and center of pressure
position. We achieve a force accuracy of ≤ 5.6 N for the ground
reaction forces and ≤ 13 mm in center of pressure position.
2022
Mechanical Design, Development and Testing of Bioinspired Legged Robots for Dynamic Locomotion
Eberhard Karls Universität Tübingen, Tübingen , November 2022 (phdthesis)
2021
Control Mechanisms for Postural Stability and Trunk Motion in Bipedal Running. A Numerical Study for Humans, Avians, and Bipedal Robots
Drama, Ö.
Universität Stuttgart, Stuttgart, May 2021 (phdthesis)
2020
Towards Hybrid Active and Passive Compliant Mechanisms in Legged Robots
Milad Shafiee Ashtiani, A. A. S., Badri-Sproewitz, A.
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, October 2020 (poster) Accepted
Beyond Basins of Attraction: Quantifying Robustness of Natural Dynamics
Heim, S., Badri-Spröwitz, A.
May 2020 (talk)
VP above or below? A new perspective on the story of the virtual point
Drama, Ö., Badri-Spröwitz, A.
Dynamic Walking, May 2020 (poster)
The spring inverted pendulum model with an extended trunk (TSLIP) is widely used to investigate the postural stability in bipedal locomotion [1, 2]. The challenge of the model is to define a hip torque that generates feasible gait patterns while stabilizing the floating trunk. The virtual point (VP) method is proposed as a simplified solution, where the hip torque is coupled to the passive compliant leg force via a virtual point. This geometric coupling is based on the assumption that the instantaneous ground reaction forces of the stance phase (GRF) intersect at a single virtual point.
Viscous Damping in Legged Locomotion
Mo, A., Izzi, F., Haeufle, D. F. B., Badri-Spröwitz, A.
Dynamic Walking, May 2020 (poster)
Damping likely plays an essential role in legged animal locomotion, but remains an insufficiently understood mechanism. Intrinsic damping muscle forces can potentially add to the joint torque output during unexpected impacts, stabilise movements, convert the system’s energy, and reject unexpected perturbations.
How Quadrupeds Benefit from Lower Leg Passive Elasticity
Ruppert, F., Badri-Spröwitz, A.
Dynamic Walking, May 2020 (poster)
Recently developed and fully actuated, legged robots start showing exciting locomotion capabilities, but rely heavily on high-power actuators, high-frequency sensors, and complex locomotion controllers. The engineering solutions implemented in these legged robots are much different compared to animals. Vertebrate animals share magnitudes slower neurocontrol signal velocities [1] compared to their robot counterparts. Also, animals feature a plethora of cascaded and underactuated passive elastic structures [2].
Viability in State-Action Space. Connecting Morphology, Control, and Learning
Eberhard Karls Universität Tübingen, Tübingen, February 2020 (phdthesis)
Potential for elastic soft tissue deformation and mechanosensory function within the lumbosacral spinal canal of birds
Kamska, V., Daley, M., Badri-Spröwitz, A.
Society for Integrative and Comparative Biology Annual Meeting (SICB Annual Meeting 2020), January 2020 (poster)
2018
Impact of Trunk Orientation for Dynamic Bipedal Locomotion
Drama, Ö.
Dynamic Walking Conference, May 2018 (talk)
Impact of trunk orientation for dynamic bipedal locomotion
My research revolves around investigating the functional demands of bipedal running, with focus on stabilizing trunk orientation. When we think about postural stability, there are two critical questions we need to answer: What are the necessary and sufficient conditions to achieve and maintain trunk stability?
I am concentrating on how morphology affects control strategies in achieving trunk stability. In particular, I denote the trunk pitch as the predominant morphology parameter and explore the requirements it imposes on a chosen control strategy.
To analyze this, I use a spring loaded inverted pendulum model extended with a rigid trunk, which is actuated by a hip motor. The challenge for the controller design here is to have a single hip actuator to achieve two coupled tasks of moving the legs to generate motion and stabilizing the trunk. I enforce orthograde and pronograde postures and aim to identify the effect of these trunk orientations on the hip torque and ground reaction profiles for different control strategies.