위치 불확실성 감소를 위한 중첩 초음파 센서 링의 설계

김성복,장재희 제어로봇시스템학회 2009 제어로봇시스템학회 각 지부별 자료집 Vol.2009 No.12

This paper presents the principle of reducing the positional uncertainty inherent to an ultrasonic sensor using overlapped ultrasonic sensors and the effective arrangement of ultrasonic sensors for reduced positional uncertainty. It is assumed that ultrasonic sensors used are of a wider beam width which are avaiable at a lower cost. First, for both single and double obstacles, we explain that the overlapped beam pattern of two adjacent ultrasonic sensors can reduce the positional uncertaint of an individual ultrasonic sensor. With the entire sensing zone of two ultrasonic sensors divided into three smaller sub zones, how to determine the sub zone where the detected obstacle belongs from the measurements of two ultrasonic sensors. Next, aiming at reduced positional uncertainty, we propose a optimal design of an ultrasonic sensor ring in which a set of ultrasonic sensors are arranged at a regular interval with their beams overlapped. As an example, the optimal design of an overlapped ultrasonic sensor ring using commercial ultrasonic sensors having a low directivity is given.

중첩 초음파 센서 링의 성능 평가, 최적 설계 및 복합 장애물 탐지

김성복,김현빈,Kim, Sung-Bok,Kim, Hyun-Bin 한국융합신호처리학회 2011 융합신호처리학회 논문지 (JISPS) Vol.12 No.4

This paper presents the performance evaluation. optimal design. and complex obstacle detection of an overlapped ultrasonic sensor ring by introducing a new concept of effective beam width. It is assumed that a set of ultrasonic sensors of the same type are arranged along a circle of nonzero radius at regular spacings with their beams overlapped. First, the global positional uncertainty of an overlapped ultrasonic sensor ring is expressed by the average value of local positional uncertainty over the entire obstacle detection range. The effective beam width of an overlapped ultrasonic sensor ring is assessed as the beam width of a single ultrasonic sensor having the same amount of global positional uncertainty, from which a normalized obstacle detection performance index is defined. Second. using the defined index, the design parameters of an overlapped ultrasonic sensor ring are optimized for minimal positional uncertainty in obstacle detection. For a given number of ultrasonic sensors, the optimal radius of an overlapped ultrasonic sensor ring is determined, and for a given radius of an overlapped ultrasonic sensor ring, the optimal number of ultrasonic sensors is determined. Third, the decision rules of positional uncertainty zone for multiple obstacle detection are provided based on the inequality relationships among obstacle distances by three adjacent ultrasonic sensors. Using the provided rules, the obstacle outline detection is performed in a rather complex environment consisting of several obstacles of different shapes. 본 논문에서는 유효 빔 폭 개념을 새로이 도입하여 중첩 초음파 센서 링의 성능 평가, 최적 설계, 그리고 복합 장애물 탐지에 대해 기술하도록 한다. 일군의 동종 저지향성 초음파 센서들이 반경이 영이 아닌 원주 상에 일정 간격으로 상호 빔 폭이 중첩되도록 배치된다고 가정한다. 첫째, 중첩 초음파 센서 링의 전역 위치 불확실성을 전체 장애물 탐지 범위 내에서의 국부적 위치 불확실성의 평균값으로 나타낸다. 중첩 초음파 센서 링의 유효 빔 폭을 동일한 전역 위치 불확실성을 갖는 단일 초음파 센서의 빔 폭으로 산정하고 이를 바탕으로 정규화된 장애물 탐지 성능 평가 지수를 정의한다. 둘째, 정의된 성능 평가 지수를 이용하여 장애물 탐지 시 위치 불확실성이 최소화되도록 중첩 초음파 센서 링의 설계 사양을 최적화한다. 주어진 초음파 센서의 사용 개수에 대한 중첩 초음파 센서 링의 최적 반경 그리고 주어진 중첩 초음파 센서 링의 반경에 대한 초음파 센서의 최적 사용 개수를 결정한다. 셋째, 3개의 인접 초음파 센서로부터의 장애물 거리 간의 대소 관계에 의거한 복수 장애물의 위치 불확실성 영역 판정 기준을 제시한다. 제시된 위치 불확실성 영역판정 기준을 이용하여 다양한 형태의 장애물로 구성된 복합 장애물 환경에서의 장애물 윤곽 추출 결과를 보인다.

고분해능 장애물 탐지를 위한 중첩 초음파 센서 링의 최적 설계

김성복,김현빈,Kim, Sung-Bok,Kim, Hyun-Bin 제어로봇시스템학회 2011 제어·로봇·시스템학회 논문지 Vol.17 No.2

This paper presents the optimal design of an overlapped ultrasonic sensor ring for high resolution obstacle detection of an autonomous mobile robot. It is assumed that a set of low directivity ultrasonic sensors of the same type are arranged along a circle of nonzero radius at a regular spacing with their beams overlapped. First, taking into account the dead angle region, the entire range of obstacle detection is determined with reference to the center of an overlapped ultrasonic sensor ring. Second, the optimal design index of an overlapped ultrasonic sensor ring is defined as the area closeness of three sensing subzones resulting from beam overlap. Third, the lower and upper bounds on the number of ultrasonic sensors are derived, which can guarantee minimal beam overlap and also avoid excessive beam overlap among adjacent ultrasonic sensors. Fourth, employing a commercial low directivity ultrasonic sensor, an optimal design example of an overlapped ultrasonic sensor ring is given along with the ultrasonic sensor ring prototype mounted on top of a mobile robot. Finally, some experimental results using our prototype ultrasonic sensor ring are given to demonstrate the validity and performance of an optimally overlapped ultrasonic sensor ring for high resolution obstacle detection.

효과적인 빔 폭 중첩을 이용한 고성능 장애물 탐지용 중첩 초음파 센서 링의 최적 설계

김성복,김현빈,Kim, Sung-Bok,Kim, Hyun-Bin 한국융합신호처리학회 2011 융합신호처리학회 논문지 (JISPS) Vol.12 No.1

본 논문에서는 인접 초음파 센서간 효과적인 빔 폭 중첩을 이용하여 고성능 장애물 탐지를 위한 중첩 초음파 센서 링을 최적 설계하는 방법에 대해 체계적으로 기술하도록 한다. 기본적으로 일군의 동종 저지향성 초음파 센서들이 일정 간격으로 상호 빔 폭이 중첩되도록 원형 배치된다고 가정한다. 첫째 초음파 센서의 실제와 단순화된 빔 패턴 그리고 빔 폭 내의 장애물 위치 추정을 위한 여러 센서 모델에 대해 소개한다. 둘째, 중첩 초음파 센서 링의 장애물 탐지 범위와 장애물 위치 추정을 위한 간단한 센서 모델에 대해 기술한다. 셋째, 타원과 비타원 형태의 빔 패턴에 대해 각각, 장애물 탐지 시 위치 불확실성이 최소화되도록 중첩 초음파 센서 링을 설계하기 위한 지수를 정의한다. 넷째, 최소한의 빔 폭 중첩 보장과 과도한 빔 폭 중첩 회피를 위해 요구되는 중첩 초음파 센서 링의 구조적 사양에 대한 제한 조건을 유도한다. 다섯째, 주어진 중첩 초음파 센서 링의 반경에 대한 초음파 센서의 최적 사용 개수와 주어진 초음파 센서의 사용 개수에 대한 중첩 초음파 센서 링의 최적 반경을 결정한다. 본 논문 전반에 걸쳐, 대표적인 상용 저지향성 초음파 센서로서 Murata사의 MA40B8이 채택되었다. This paper presents the systematic optimal design of an overlapped ultrasonic sensor ring for high performance obstacle detection using effective beam overlap. Basically, a set of low directivity ultrasonic sensors of the same type are arranged in a circle at regular intervals with their beams overlapped. First, both real and simplified beam patterns of an ultrasonic sensor and several sensor models for obstacle position estimation within its beam pattern are introduced. Second, the obstacle detection range of an overlapped ultrasonic sensor ring and its simple sensor model for obstacle position estimation are described. Third, for both conic and non-conic shaped beam pattern, the design indices of an overlapped ultrasonic sensor ring for minimal positional uncertainty in obstacle detection are defined. Fourth, the constraints imposed on the structural parameters of an overlapped ultrasonic sensor ring to guarantee non empty beam overlap and to avoid excessive beam overlap are derived. Fifth, the optimal number of ultrasonic sensors for a given radius of an overlapped ultrasonic sensor ring and the optimal radius of an overlapped ultrasonic sensor ring are determined. Throughout this paper, the MA40B8 from Murata Inc. is taken as a representative commercial low directivity ultrasonic sensor.

중첩 초음파 센서 링 최적 설계 시 기하학적 고려 사항

김성복(Sungbok Kim),김현빈(Hyunbin Kim) 제어로봇시스템학회 2010 제어로봇시스템학회 각 지부별 자료집 Vol.2010 No.12

This paper presents the geometric constraints in the optimal design of an overlapped ultrasonic sensor ring. It is assumed that a set of ultrasonic sensors of the same type are arranged in a circle of nonzero radius at a regular spacing with their beams overlapped. For effective beam overlap of an overlapped ultrasonic sensor ring, it is required to guarantee non empty beam overlapping between adjacent ultrasonic sensors and also to avoid excessive beam overlapping among adjacent ultrasonic sensors. First, for a given radius of an overlapped ultrasonic sensor ring, the restriction on the number of ultrasonic sensors for effective beam overlap is analyzed. Then, for a given number of ultrasonic sensors, the restriction on the radius of an overlapped ultrasonic sensor ring is analyzed.

Analysis on the Effect of Beam Overlap of a Low Directivity Ultrasonic Sensor Ring

Sungbok Kim,Hyunbin Kim 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

This paper presents the analysis on the effect of beam overlap of a low directivity ultrasonic sensor ring. It is assumed that a set of ultrasonic sensors of the same type are arranged along a circle of non-zero radius at regular spacings with their beams overlapped. Due to beam overlap of an ultrasonic sensor ring, the detection zone of each ultrasonic sensor can be divided into three smaller sub-zones, and also for a given obstacle distance, its uncertainty arc can be divided into three smaller sub-arcs. First, taking into account the range of sensing distance as well as the dead angle region, the entire range of obstacle detection of an overlapped ultrasonic sensor ring is specified. Second, the effective beam width of an overlapped ultrasonic sensor ring is assessed in terms of the lengths of uncertainty sub-arcs. Third, alternative assessment of effective beam width of an overlapped ultrasonic sensor ring is proposed in terms of the areas of detection sub-zones. Lastly, using a commercial low directivity ultrasonic sensors, the changes of the effective beam widths depending on the parameter of an overlapped ultrasonic sensor ring are examined

Positional Uncertainty Assessment and Complex Obstacle Detection of an Ultrasonic Sensor Ring with Overlapped Beam Pattern

Sungbok Kim,Hyunbin Kim 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

This paper presents the positional uncertainty assessment and the complex obstacle detection of an ultrasonic sensor ring with overlapped beam pattern. Due to beam overlap between adjacent ultrasonic sensors, the entire sensing range of an individual ultrasonic senor can be divided into three smaller sensing subzones. First, the concept of collision free region of each ultrasonic sensor with reference to the center of an ultrasonic sensor ring is introduced. Second, the effective beam width of an overlapped ultrasonic sensor ring is defined to assess the positional uncertainty in obstacle detection. Third, high resolution single obstacle detection can be made based on the combination of two adjacent ultrasonic sensors detecting a given obstacle. Fourth, high resolution multiple obstacle detection can be made based on the inequality relationships among the obstacle distances by three consecutive ultrasonic sensors.

Simple and Complex Obstacle Detection Using an Overlapped Ultrasonic Sensor Ring

Sungbok Kim,Hyunbin Kim 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

This paper presents both simple and complex obstacle detection using an ultrasonic sensor ring with overlapped beam pattern. It is assumed that a set of ultrasonic sensors of the same type are arranged along a circle of non-zero radius at regular spacings with their beams overlapped. To assess the positional uncertainty of an overlapped ultrasonic sensor ring in obstacle detection, the obstacle distances of three adjacent ultrasonic sensors are compared. First, the positional uncertainty for single obstacle detection can be determined based on the combination of ultrasonic sensors detecting an obstacle. Second, the positional uncertainty for multiple obstacle detection can be determined based on the inequality relationship among three adjacent obstacle distances. Third, the positional uncertainty for omnidirectional obstacle detection can be determined by overlapping all the uncertainty arcs obtained for every three consecutive ultrasonic sensors.

자율 주행 이동로봇을 위한 중첩 초음파 센서 링의 설계 방법

김성복,김현빈 제어로봇시스템학회 2010 제어로봇시스템학회 국내학술대회 논문집 Vol.2010 No.5

This paper presents the design method of an overlapped ultrasonic sensor ring for the obstacle detection of autonomous mobile robots. Due to the overlapped beam pattern, the entire sensing zone of each ultrasonic sensor is divided into three sensing subzones. First, taking into the positional uncertainty in obstacle detection into account, the design index for an overlapped ultrasonic sensor ring is defined as the closeness in area between the unoverlapped and the overlapped sensing subzones. Next, using commercial low directivity ultrasonic sensors, two optimal design problems are dealt with to find the optimal number of sensors and the optimal radius of the sensor ring. An example of optimal design is given along with its prototype installed on top of a mobile robot.

중첩 초음파 센서 링의 장애물 탐지 성능 지표 비교 분석

김성복(Sungbok Kim),김현빈(Hyunbin Kim) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.4

This paper presents a comparative analysis on three different types of performance indices of obstacle detection for an overlapped ultrasonic sensor ring. Due to beam overlap, the entire sensing zone of each ultrasonic sensor can be divided into three smaller sensing subzones, which leads to significant reduction of positional uncertainty in obstacle detection First, the positional uncertainly in obstacle detection is expressed in toms of the area of a sensing subzone, and type 1 performance index is then defined as the area ratio of side and colter sensing suhzones. Second, based on the area of a sensing subzone, type 2 performance index is defined taking into account the size of the entire range of obstacle detection as well as the degree of the positional uncertainty in obstacle detection. Third, the positional uncertainty in obstacle detection is now expressed in terms of the length of the uncertainty arc spanning a sensing subzone, and type 3 performance index is thai defined as the average value of the uncertainty are Lengths over the entire range of obstacle detection. Fourth, using a commercial low directivity ultrasonic sensor, the changes of three different performance indices depending on the parameter of an overlapped ultrasonic sensor ring are examined and compared.