Camera-to-robot (also known as eye-to-hand) calibration is a critical component of vision-based robot manipulation. Traditional marker-based methods often require human intervention for system setup. Furthermore, existing autonomous markerless calibration methods typically rely on pre-trained robot tracking models that impede their application on edge devices and require fine-tuning for novel robot embodiments. To address these limitations, this paper proposes a model-based markerless camera-to-robot calibration framework, ARC-Calib, that is fully autonomous and generalizable across diverse robots and scenarios without requiring extensive data collection or learning. First, exploratory robot motions are introduced to generate easily trackable trajectory-based visual patterns in the camera’s image frames. Then, a geometric optimization framework is proposed to exploit the coplanarity and collinearity constraints from the observed motions to iteratively refine the estimated calibration result. Our approach eliminates the need for extra effort in either environmental marker setup or data collection and model training, rendering it highly adaptable across a wide range of real-world autonomous systems. Extensive experiments are conducted in both simulation and the real world to validate its robustness and generalizability.

Traditional robot control relies on analytical methods that require precise system models, which are hard to apply in real-world settings and limit generalization to arbitrary tasks. However, systems like serial manipulators and passively adaptive hands feature inherently stable regions without control discontinuities like loss of contact or singularities. In these regions, approximate controllers focusing on the correct direction of motion enable successful coarse manipulation. When coupled with a rough estimation of the motion magnitude, precision manipulation is achieved. Leveraging this insight, we introduce a novel inverse Jacobian estimation method that independently estimates the primary motion direction and magnitude of the manipulator’s actuators. Our method efficiently estimates the direct mapping from task to actuator space with no need for a priori system knowledge enabling the same framework to control both hands and arms without compromising task performance. We present a novel control method with no a priori knowledge for precision manipulation. Experiments on the Yale Model O hand, Yale Stewart Hand, and a UR5e arm demonstrate that the inverse Jacobians estimated via our approach enable real-time control with submillimeter precision in manipulation tasks. These results highlight that online self-ID data alone is sufficient for precise real-world manipulation.

The ability to plan and control robotic in-hand manipulation is challenged by several issues, including the required amount of prior knowledge of the system and the sophisticated physics that varies across different robot hands or even grasp instances. One of the most direct models of in-hand manipulation is the inverse Jacobian, which can directly map from the desired in-hand object motions to the required hand actuator controls. However, acquiring such inverse Jacobians without complex hand-object system models is typically infeasible. We present a method for controlling in-hand manipulation using inverse Jacobians that are self-identified by a particle filter-based estimation scheme that leverages the ability of underactuated hands to maintain a passively stable grasp during self-identification movements. This method requires no a priori knowledge of the specific hand-object system and learns the system’s inverse Jacobian through small exploratory motions. Our system approximates the underlying inverse Jacobian closely, which can be used to perform manipulation tasks across a range of objects successfully. With extensive experiments on a Yale Model O hand, we show that the proposed system can provide accurate in-hand manipulation of sub-millimeter precision and that the inverse Jacobian-based controller can support real-time manipulation control of up to 900Hz.

Calibrating robots into their workspaces is crucial for manipulation tasks. Existing calibration techniques often rely on sensors external to the robot (cameras, laser scanners, etc.) or specialized tools. This reliance complicates the calibration process and increases the costs and time requirements. Furthermore, the associated setup and measurement procedures require significant human intervention, which makes them more challenging to operate. Using the built-in force-torque sensors, which are nowadays a default component in collaborative robots, this work proposes a self-calibration framework where robot-environmental spatial relations are automatically estimated through compliant exploratory actions by the robot itself. The self-calibration approach converges, verifies its own accuracy, and terminates upon completion, autonomously purely through interactive exploration of the environment’s geometries. Extensive experiments validate the effectiveness of our self-calibration approach in accurately establishing the robot-environment spatial relationships without the need for additional sensing equipment or any human intervention.

Building hand-object models for dexterous in-hand manipulation remains a crucial and open problem. Major challenges include the difficulty of obtaining the geometric and dynamical models of the hand, object, and time-varying contacts, as well as the inevitable physical and perception uncertainties. Instead of building accurate models to map between the actuation inputs and the object motions, this work proposes to enable the hand-object systems to continuously approximate their local models via a self-identification process where an underlying manipulation model is estimated through a small number of exploratory actions and non-parametric learning. With a very small number of data points, as opposed to most data-driven methods, our system self-identifies the underlying manipulation models online through exploratory actions and non-parametric learning. By integrating the self-identified hand-object model into a model predictive control framework, the proposed system closes the control loop to provide high accuracy in-hand manipulation. Furthermore, the proposed self-identification is able to adaptively trigger online updates through additional exploratory actions, as soon as the self-identified local models render large discrepancies against the observed manipulation outcomes. We implemented the proposed approach on a sensorless underactuated Yale Model O hand with a single external camera to observe the object's motion. With extensive experiments, we show that the proposed self-identification approach can enable accurate and robust dexterous manipulation without requiring an accurate system model nor a large amount of data for offline training.