• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1609-1612
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• 1997

Kinematically redundantant manipulators have a nimber of potential advantages over nonredundant ones. Questions associated with manipulability measures for (non)redundant manipulators derived by minimum 2-norm solution and minimum infinity-norm solution in unit joint velocity are examined in detail.

• ETRI Journal
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• v.21 no.2
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• pp.9-21
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• 1999

In this paper, to enhance the performance of ${\pi}$/4-DQPSK (${\pi}$/4-differential quadrature phase shift keying), the scheme using nonredundant multiple error correction is proposed and investigated. This scheme for the differential detection of ${\pi}$/4-DQPSK uses the signal output which is delayed for more than two time slots as the parity check bit and applies it to nonredundant multiple error correction. The proposed system was used for studying the performance of ${\pi}$/4-DQPSK with Nonredundant Error Correction (NEC) in additive white Gaussian noise (AWGN) and Nakagami fade modeled mobile communication channel, and it was observed that the performance increased as the error correction capability increased.

• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.486-494
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• 2006

In this paper, we present the complete isotropy analysis of a caster wheeled omnidirectional mobile robot (COMR) with nonredundant/redundant actuation. It is desirable for robust motion control to keep a COMR close to the isotropy but away from the singularity as much as possible. First, with the characteristic length introduced, the kinematic model of a COMR is obtained based on the orthogonal decomposition of the wheel velocities. Second, a general form of the isotropy conditions of a COMR is given in terms of physically meaningful vector quantities which specify the wheel configuration. Third, for all possible nonredundant and redundant actuation sets, the algebraic expressions of the isotropy conditions are derived so as to identify the isotropic configurations of a COMR. Fourth, the number of the isotropic configurations, the isotropic characteristic length, and the optimal initial configuration are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2356-2361
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• 2005

In this paper, we present a complete isotropy analysis of a caster wheeled omnidirectional mobile robot(COMR) with nonredundant/redundant actuation. The motivation of this work is that the omnidirectional mobility loses significance in motion control unless the isotropy characteristics is maintained well. First, with the characteristic length introduced, the kinematic model of a COMR is obtained based on the orthogonal decomposition of the wheel velocities. Second, a general form of the isotropy conditions of a COMR is given in terms of physically meaningful vector quantities which describe the wheel configurations. Third, for all possible nonredundant and redundant actuation sets, the algebraic expressions of the isotropy conditions are derived to completely identify the isotropic configurations of a COMR. Fourth, the number of the isotropic configurations and the characteristic length required for the isotropy are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1948-1959
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• 1999

The error rate performance of the proposed $\pi$/4-differential quadructure phase shift keying( $\pi$/4-DQPSK) with nonredundant multiple error correction is analyzed for Nakagami fading channel. The scheme for differential detection of $\pi$/4-QPSK with nonredundant multiple error correction utilizes the output that employ the received signal delayed by more than two time slots. It was observed that the performance increased as the error correction capability increased.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.120.2-120
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• 2001

This paper presents the analysis on the manipulability of a wheeled mobile manipulator which consists of a wheeled mobile platform and a manipulator atop. It is assumed that the mobile platform is a deficient system and the manipulator is a nonredundant system, but the mobile manipulators as a whole is a redundant system. First Yoshikawa´s definition of the manipulability ellipsoid for a redundant/nonredundant system is extended to a deficient system. Second, the effects of the nonholonomic constraint of the mobile platform and the location the mobile platform and the manipulator is analyzed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.4
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• pp.138-144
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• 1989

In this paper, a new method is proposed to remove the logical redundancy for the gate-level circuit optimization. In this method, only the fanout-branch signals in the circuits, not all the signals, are examined for redundancy. When a signal is determined to be nonredundant, other nonredundant signals are found out by the efficient procedure, using only the informations which are generated in the course of the redundancy-check. In order to avoid the re-examination of a signal for redudancy, a heuristic method is proposed to determine the redundancy-checking order of signals. The proposed method is heuristic, based on the VLSI test theory. It is much faster than other methods, since it does not reexamine a signal for redundancy.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.291-295
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• 1991

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1990.10a
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• pp.52-57
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• 1990

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.240-246
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• 1992

In the paper, the differential detection techniques of 3-h CPM signals whose modulation index is varied periodically are proposed and their error performances are analyzed. We select the modulation index sets which are proper to the differential detection and propose the differential detectors which detect symbol with 3 bits per smapling period of 3T and detect a bit per sampling period of T. Applying the nonredundant error correction circuit and viterbi algorithm to differential detection of 3-h CPM. We ascertain the error performances are improved.