Wen-Yo Lee

Force control and breakthrough detection of a bone-drilling system

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system that drills with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the dc drilling motor control and the feed rate control are driven by force control in order to accommodate the system impedance. Moreover, breakthrough detection comes from to the threshold information of the thrust force as well as the trend of both the drilling torque and the feed rate. The proposed technique was experimentally verified through the drilling of pig bones, and the results are in accordance with the theoretical model both in the bone-drilling process and at the point of breakthrough.

Low-Latency Digit-Serial Systolic Double Basis Multiplier over

Recently in cryptography and security, the multipliers with subquadratic space complexity for trinomials and some specific pentanomials have been proposed. For such kind of multipliers, alternatively, we use double basis multiplication which combines the polynomial basis and the modified polynomial basis to develop a new efficient digit-serial systolic multiplier. The proposed multiplier depends on trinomials and almost equally space pentanomials (AESPs), and utilizes the subquadratic Toeplitz matrix-vector product scheme to derive a low-latency digit-serial systolic architecture. If the selected digit-size is d bits, the proposed digit-serial multiplier for both polynomials, i.e., trinomials and AESPs, requires the latency of 2⌈√{m/d⌉, while traditional ones take at least O(⌈m/d⌉) clock cycles. Analytical and application-specific integrated circuit (ASIC) synthesis results indicate that both the area and the time × area complexities of our proposed architecture are significantly lower than the existing digit-serial systolic multipliers.

\mbi GF{(2^m})

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system that drills with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the dc drilling motor control and the feed rate control are driven by force control in order to accommodate the system impedance. Moreover, breakthrough detection comes from to the threshold information of the thrust force as well as the trend of both the drilling torque and the feed rate. The proposed technique was experimentally verified through the drilling of pig bones, and the results are in accordance with the theoretical model both in the bone-drilling process and at the point of breakthrough.

Using Subquadratic Toeplitz Matrix-Vector Product Approach

This paper presents a time-invariant feedback controller that simultaneously regulates the ZMP (zero-moment point) position and the joint configuration of a 3D biped in order to achieve an asymptotically, periodic walking gait for a 3D bipedal robot with feet. The cyclic walking gait is composed of a successive single-support phase and an impulsive impact with full plane-contact between the feet and the ground. The biped robot has 10 DOFs (degrees of freedom) in the single-support phase and 10 actuators. In order to avoid the unexpected rotation of the supporting foot, the position of the ZMP in the horizontal plane has to be controlled. It is also desired that the feedback controller tracks a parameterized reference trajectory to achieve walking stability. We use the method of virtual constraints previously implemented for controlling point-feet bipedal robots to create a set of parameterized reference walking trajectories. By creating the hybrid zero dynamics, an orbital stability study with Poincare map is evaluated in a reduced space. We then design a supplemental event-based feedback controller to enhance walking stability. The walking gait has an average walking speed of 0.76m/sec (or 0.72 body lengths per second) in the simulation study.

Force control and breakthrough detection of a bone drilling system

The aim of this study is to develop a surgical navigation system applied to drilling. The System combines three phases, including: (i) Immersive handheld of force feedback device. (ii) Three-dimensional model for the visual processing of medical images. (iii) Stable grip of the robotic arm, which we transform and overlap the medical imaging and the spatial coordinates of the force feedback device in order to enhance the accuracy of the robotic arm. The surgical navigation system provides a remote user interface that surgeons can make both the preoperative surgical planning and simulation drilling path. Furthermore, the system will control the robotic arm precisely to reach the affected area for drilling operations and avoid touching other important organization of patient to reduce the damage. To sum up, we hope to develop the surgical navigation system that can make the drilling surgical treatment more safe and reliable.

Planning and Control of Stable Walking for a 3D Bipedal Robot

In this paper, we present a new (4,2)-way Toom-Cook algorithm using finite field interpolation. The proposed algorithm uses multi-evaluation scheme to construct a digit-serial multiplier over GF(2m) which involves subquadratic space-complexity. From theoretical analysis, it is found that the proposed architecture has O(mlog4 5) space complexity and O(mlog4 2) latency, which is significantly less than traditional digit-serial multipliers.

Robotic arm drilling surgical navigation system

In this paper, we present novel fault-tolerant architecture for bit-parallel polynomial basis multiplier over GF(2m) which can correct the erroneous outputs using linear code. We have designed a parity prediction circuit based on the code generator polynomial that leads lower space overhead. For bit-parallel architectures, the space overhead is about 11%. Moreover, there is only marginal time overhead due to incorporation of error-correction capability that amounts to 3.5% in case of the bit-parallel multiplier. Unlike the existing concurrent error correction (CEC) multipliers or triple modular redundancy (TMR) techniques for single error correction, the proposed architectures have multiple error-correcting capabilities.

Subquadratic space complexity digit-serial multiplier over binary extension fields using Toom-Cook algorithm

In this paper, we propose a hierarchical fuzzy rule based classifier (HFRBC) for the classification problem with large number of classes and continuous attributes. A hierarchical clustering concept is introduced to achieve a finer fuzzy partition. Critical attributes are used to perform the cluster splitting and generate a cluster splitting tree. The effective attributes for the terminal clusters in the cluster splitting tree are picked so as to reduce the size of the fuzzy-rule set and hence reduce the computational complexity. The fuzzy rule generation procedures and classification procedures of the proposed HFRBC are simple and easily implemented. We have successfully applied the HFRBC to the classification problem of the working wafers in an ion implanter.

Fault-Tolerant Bit-Parallel Multiplier for Polynomial Basis of GF(2m)

The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process.

An effective and efficient hierarchical fuzzy rule based classifier

A motion control chip implementation method will be shown in this paper. The implementation is based on the Verilog HDL which is a popular tool for designing a special function FPGA, especially on the industrial field. There are several components needed in a control chip according to the motion control requirements. The major components are: encoder readers, PWM generators, subtracter/Adder, PID controller, as well as the communication ports. These algorithms have been developed on an FPGA, which is used to control an IR2100 based DC motor drive for a mobile robot. The IR2100 based drive is also been introduced for completing the article structure. Finally, we will show you that the motion driving module is applied on a more than 50Kg mobile robot.