Author name cluster

Howard Jay Chizeck

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8 papers

1 author row

IROS Conference 2015 Conference Paper

Haptic passwords

Junjie Yan
Kevin Huang 0001
Tamara Bonaci
Howard Jay Chizeck

Haptic technologies have made it possible for human users to interact with cyber systems not only via traditional interfaces like keyboards and mice but also by applying force and motion. With these extra information channels, how a user haptically interacts with a system potentially presents unique user dependent features and can thus be used for authentication purposes. In this paper, we propose a new biometric technology based on haptic interaction. Our technique leverages artificial neural network (ANN) based wavelet analysis to perform user identification. Identification and authentication are done in two steps: a discrete wavelet transform (DWT) is applied to extract features, and then the neural network is used to perform identification and authentication. The performance of the model is evaluated based on identification and authentication accuracies. The results show that our proposed haptic password system has a high identification accuracy and that it is resistant to forgery attacks.

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ICRA Conference 2015 Conference Paper

Sensor-aided teleoperated grasping of transparent objects

Kevin Huang 0001
Liang-Ting Jiang
Joshua R. Smith 0001
Howard Jay Chizeck

This paper presents a method of augmenting streaming point cloud data with pretouch proximity sensor information for the purposes of teleoperated grasping of transparent targets. When using commercial RGB-Depth (RGB-D) cameras, material properties can significantly affect depth measurements. In particular, transparent objects are difficult to perceive with RGB images and commercially available depth sensors. Geometric information of such objects needs to be gathered with additional sensors, and in many scenarios, it is of interest to gather this information without physical contact. In this work, a non-contact pretouch sensor fixed to the robot end effector is used to sense and explore physical geometries previously unobserved. Thus, the point cloud representation of an unknown, transparent grasp target, can be enhanced through telerobotic exploration in real-time. Furthermore, real-time haptic rendering algorithms and haptic virtual fixtures used in combination with the augmented streaming point clouds assist the teleoperator in collision avoidance during exploration. Theoretical analyses are performed to design virtual fixtures suitable for pretouch sensing, and experiments show the effectiveness of this method to gather geometry data without collision and eventually to successfully grasp a transparent object.

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ICRA Conference 2013 Conference Paper

A method for constraint-based six degree-of-freedom haptic interaction with streaming point clouds

Fredrik Ryden
Howard Jay Chizeck

This paper presents a constraint-based method for haptic interaction between an arbitrary voxelized polygon tool and a streaming point cloud derived from a depth sensor. Using the presented method, a user can interact with both dynamic as well as static point cloud representations of real objects captured in real-time. Every depth image frame is filtered and surface normals are calculated in real-time. For movement of the virtual tool, a ‘quasi-static’ simulation is used. The innovations of this work include the extension of haptic rendering from streaming point clouds to six degrees of freedom. This is appropriate for co-robotic tasks where haptic feedback to the user is combined with remote control of a robot.

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ICRA Conference 2012 Conference Paper

Application of Unscented Kalman Filter to a cable driven surgical robot: A simulation study

Srikrishnan Ramadurai
Sina Nia Kosari
Hawkeye H. I. King
Howard Jay Chizeck
Blake Hannaford

Cable driven power transmissions are used in applications such as haptic devices, surgical robots etc. The use of flexible cable based power transmission often causes relative motion between the motor actuator and mechanism joint during operation due to the elasticity of the cable. State-space control methods can be used to improve performance, but may require state estimates. For nonlinear systems, the Unscented Kalman Filter (UKF) provides a computationally efficient way to obtain state estimates. The UKF is applied here to a simulation of a minimially invasive surgical robot, to study the state estimation for a cable driven system with nonlinear dynamics. State estimates from the UKF are compared with the known states available from the simulation. These state estimates are also utilized by two different controllers interacting with the simulation to test the UKF performance under closed loop control. We tested the UKF performance with error perturbations in the system model's cable stiffness parameter.

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IROS Conference 2012 Conference Paper

Forbidden-region virtual fixtures from streaming point clouds: Remotely touching and protecting a beating heart

Fredrik Ryden
Howard Jay Chizeck

Several established methods for remote touching using non-contact sensors exist. Applications for these methods are primarily within the field of robotic teleoperation. In surgical robotics it would be useful to not only touch, but also be able to maintain a distance from a certain organ. The latter can be done using non-contact sensors such as cameras. The novelty in this paper is the idea of combining forbidden-region virtual fixtures with haptic rendering from streaming point clouds. This is then used to protect as well as remotely touch a beating heart without any a priori knowledge of the heart geometry (such as from CT/MR scans).

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ICRA Conference 2012 Conference Paper

Robotic compression of soft tissue

Sina Nia Kosari
Srikrishnan Ramadurai
Howard Jay Chizeck
Blake Hannaford

This paper investigates automation of soft tissue compression for robot-assisted surgery. This is a fundamental task in surgery and includes interaction with a variety of tissues with unknown properties. In addition, due to sterilization and size constraints the use of contact force and position sensors are often avoided in surgical applications. We propose an Adaptive Model Predictive Control approach for execution of given tool trajectories in contact with unknown tissues in the absence of contact measurements. The Unscented Kalman Filter is employed in advance of system operation to identify the dynamics of a cable driven manipulator. These dynamics are then used to estimate contact force and position in free motion and in contact with tissue. An optimal control problem for automating tissue compression is formulated and is solved in real-time using Differential Dynamic Programming with Automatic Differentiation. The proposed methods are evaluated in experiments on an artificial tissue sample with unknown properties.

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IROS Conference 2011 Conference Paper

Proxy method for fast haptic rendering from time varying point clouds

Fredrik Ryden
Sina Nia Kosari
Howard Jay Chizeck

This paper proposes a novel algorithm for haptic rendering from time varying point clouds captured using an Xbox Kinect RGB-D camera. Existing methods for point-based haptic rendering using a proxy can not directly be applied in this situation since no information about the underlying objects is given. This paper extends the notion of proxy to point clouds. The haptic algorithm presented here renders haptic forces from point clouds captured in real-time representing both static and dynamic objects.

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IROS Conference 2007 Conference Paper

Comparison of transient performance in the control of soft tissue grasping

Xiaolong Yu
Howard Jay Chizeck
Blake Hannaford

In robot-assisted surgery, surgical tools interact with tissues that have nonlinear mechanical properties. For situations where a pre-specified trajectory of tool positions (or applied forces) is desired, there are many controller designs that might be used. Four candidates are comparatively evaluated here, via computer simulation involving a nonlinear model of soft tissue behavior during grasping actions. The parameters for this model were obtained experimentally (in earlier work). The four candidate controllers are: (1) a well- tuned PID controller; (2) feedback linearization in combination with deadbeat control; (3) an optimal open-loop control law obtained via minimization of a quadratic cost function; and (4) a model predictive controller. Simulation trials are used to compare the transient performance of these candidate controllers under different assumptions regarding input and output noises. The conditions where each of the candidates is best are characterized.

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