Optimal Prioritized Dissipation and Closed-Form Damping Limitation under Actuator Constraints for Haptic Interfaces

Camilla Celli; Andrea Bini; Valerio Novelli; Alessandro Filippeschi; Francesco Porcini; Antonio Frisoli

cs.ROMar 27, 2026

Optimal Prioritized Dissipation and Closed-Form Damping Limitation under Actuator Constraints for Haptic Interfaces

Authors: Camilla Celli, Andrea Bini, Valerio Novelli, Alessandro Filippeschi, Francesco Porcini, Antonio Frisoli

Organizations: Scuola Superiore Sant’Anna, IIM Institute, PERCRO Laboratory, Pisa, Italy · Scuola Superiore Sant’Anna, Department of Excellence in Robotics and AI, Pisa, Italy

Abstract

In haptics, guaranteeing stability is essential to ensure safe interaction with remote or virtual environments. One of the most relevant methods at the state-of-the-art is the Time Domain Passivity Approach (TDPA). However, its high conservatism leads to a significant degradation of transparency. Moreover, the stabilizing action may conflict with the device's physical limitations. State-of-the-art solutions have attempted to address these actuator limits, but they still fail to account simultaneously for the power limits of each actuator while maximizing transparency. This work proposes a new damping limitation method based on prioritized dissipation actions. It prioritizes an optimal dissipation direction that minimizes actuator load, while any excess dissipation is allocated to the orthogonal hyperplane. The solution provides a closed-form formulation and is robust in multi-DoF scenarios, even in the presence of actuator and motion anisotropies. The method is experimentally validated using a parallel haptic interface interacting with a virtual environment and tested under different operating conditions.

Figures & tables

Figure 1: Block representation of an impedance-based haptic interface interacting with a virtual environment. The human operator is supposed to be passive, while the virtual environment is simulated to behave actively according to [ 9 ] . The PC is included to make the entire system passive.

Figure 2: Application of strategy [ 13 ] with anisotropic velocities. On the first row joints’ velocity are shown, where

\dot{q}_{1}

is always greater than the others during the dissipation. On the second row the limitation in norm of the torques is verified. On the last row the dissipation torque at joint 1 is demonstrated to violate the physical limits.

Figure 3: Application of strategy [ 13 ] with anisotropic actuator limits. On the first row, the limitation in the norm of the torques is satisfied. On the second row, the torque at joint 2 – which was constrained to one third of its maximum possibilities – is shown to not satisfy the physical limits.

Figure 4: Representation of the ( $f_{x}$ , $f_{y}$ ) plan. The square highlights the physical capabilities of the system, i.e. references provided to the actuators are realizable if contained in the square. $\mathbf{\hat{f}}$ is the reference force, $\mathbf{d}_{A}$ is the desired dissipation vector which generates, together with $\mathbf{\hat{f}}$ , the commanded force $\mathbf{f}_{cmd,A}$ while $\mathbf{d}_{B}$ is the limited dissipation vector which generates $\mathbf{f}_{cmd,B}$ . Since $\mathbf{f}_{cmd,A}$ is already realizable by the actuators, it should not be necessary to limit the dissipation $\mathbf{d}_{A}$ , but this fact is not taken into account in [ 13 ] .

Figure 5: Rendered and dissipated fed back force, respectively

\hat{f}

and

f_{cmd}

, along the virtual wall axis by using strategy in [ 17 ] . According to the position of the wall, positive forces are repulsive, while negative are attractive.

Figure 6: Representation in ( $f_{x}$ , $f_{x}$ ) plan of the proposed strategy. In red, high-priority dissipation is represented, directed as the reference and limited by the reference magnitude. In blue, the orthogonal low-priority direction is identified. Here, the vector $\mathbf{d}_{A}$ respects the limit along x-axis, but not along y-axis. Conversely, the proposed limitation for this direction requires $\mathbf{d}_{A}$ to be limited up to $\mathbf{d}_{B}$ , respecting the force constraints.

Figure 7: Experimental setup composed by a 3 DoFs parallel haptic interface. The virtual wall is implemented to lay in the xy-plane, parallel to the base, generating a force is in the positive z direction.

Figure 8: Experiment 1 : Application of the new strategy with anisotropic velocities. On the first row joints’ velocity are shown, where

\dot{q}_{1}

is always greater than the others during the dissipation. On the second row the norm of the actual torques is demonstrated to be lower than the norm of maximum forces. On the last row the torque at joint 1 stays below the practical limits.

Figure 9: Experiment 2 : Application of the new strategy with anisotropic actuator limits. On the first row, the limitation in the norm of the torques is satisfied. On the second row, the torque at joint 2 – which was constrained to one third of its maximum possibilities – is shown to satisfy the physical limits.

Figure 10: Experiment 3 : the figure compares the state-of-art strategy with the new one proposed by the authors. On the first row the rendered force from the virtual wall (red) is shown along with the dissipated one (blue). The second row presents the orthogonal dissipation contributions. The remaining rows highlight the actuators load both in norm and for each joint separately (where each maximum was highlighted in blue).

Figure 11: Experiment 3 : comparison between the damping factors

\alpha

in the trials with the strategy in [ 13 ] (in red) and with the strategy presented (in blue).

Haptic Feedback

Haptic feedback conveys touch, force, motion, or material properties through devices that let people and robots perceive and respond to interaction.

See all 60 papers

Power from Potential: A Survey of Electrostatic Actuators for Haptics
Jul 6, 2026Ahad M. Rauf, Ran Zhou, Eric Acome +5Haptic Feedback
Department of Mechanical Engineering at Stanford University, Stanford, California, United States of America · Division of Media Technology and Interaction Design at the KTH Royal Institute of Technology, Stockholm, Sweden · Artimus Robotics, Boulder, Colorado, United States of America +4
HACo: Learning Haptic Active Compliance for Force-Aware Dexterous Manipulation
Sep 29, 2026Naisheng Ye, Yinzhe Zhou, Junkai Zhao +5Contact-Rich Robotic Manipulation Robotic Manipulation
The University of Hong Kong, Hong Kong SAR, China · Beijing Academy of Artificial Intelligence (BAAI), Beijing, China · Johns Hopkins University, Baltimore, MD, USA
Continuous Orthogonal Mode Decomposition: Haptic Signal Prediction in Tactile Internet
Apr 10, 2026Mohammad Ali Vahedifar, Mojtaba Nazari, Qi ZhangTactile Sensing
DIGIT and Department of Electrical and Computer Engineering, Aarhus University, Denmark

Jul 6, 2026J/K move · Enter open · S save

Power from Potential: A Survey of Electrostatic Actuators for Haptics

Ahad M. Rauf, Ran Zhou, Eric Acome, Madeline Balaam+4

Department of Mechanical Engineering at Stanford University, Stanford, California, United States of America · Division of Media Technology and Interaction Design at the KTH Royal Institute of Technology, Stockholm, Sweden · Artimus Robotics, Boulder, Colorado, United States of America+4

Haptic Feedback

Open paper AskPDF arXiv

As haptic interfaces integrate more seamlessly into wearables and everyday environments, they increasingly require actuators that are soft, thin, silent, and energy efficient. However, conventional motors and temperature-responsive polymers often struggle to deliver these properties due to their bulky form factors and high power consumption. High-Voltage Electrostatic Actuators (HVEAs), which generate force by applying an electric field to localized charge concentrations using high voltages and ultra-low currents, have recently emerged as a compelling alternative due to their fast, silent, and low-power operation within highly customizable and compliant form factors. This paper presents a focused review of HVEAs for haptics, examining four major classes: electrostatic switchable adhesives, dielectric elastomer actuators, soft electrohydraulic actuators, and electrokinetic pumps. For each class, we describe their mechanisms that enable haptic output; characterize their bandwidths, force densities, and spatial scalability; and evaluate their versatility for rendering cutaneous and kinesthetic feedback across wearable and world-grounded interfaces. Through this cross-technology analysis, we identify common design constraints and emerging strategies for improving ergonomics, streamlining fabrication, and integrating self-sensing. We conclude by outlining where HVEAs are uniquely positioned to advance haptic interaction and highlighting key research directions needed to translate these technologies into practical systems.

Abstract

Haptic Feedback

Explore similar work

Power from Potential: A Survey of Electrostatic Actuators for Haptics

HACo: Learning Haptic Active Compliance for Force-Aware Dexterous Manipulation

Continuous Orthogonal Mode Decomposition: Haptic Signal Prediction in Tactile Internet