Papers by Seiichiro Katsura
IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 2015
Network control systems have been attracting attention to manage sophisticated task at a remote p... more Network control systems have been attracting attention to manage sophisticated task at a remote place where people cannot enter. However, jitter which is a fluctuation in time delay for an information to be transmitted, is a serious problem in network control systems because it deteriorates the performance of the system. Therefore, designing control system considering jitter is extremely important. Thus, this paper proposes a novel method to reduce the effect of jitter to the system under time delayed conditions. This is done by utilizing two filters that have inverse relationships and an error corrector when information is transmitted via network. The validity of the proposed system is confirmed experimentally by implementing the proposed filter to a one way information transmission and a network control system. Also, the experimental results of the proposed method is compared with conventional methods to show the effectiveness of the proposed method.
IEEJ Journal of Industry Applications, 2019
Actuator arrays that consist of a planar arrangement of actuators are widely used for transportat... more Actuator arrays that consist of a planar arrangement of actuators are widely used for transportation of objects or shaping a rough surface by controlling the actuators cooperatively. In particular, thermal displays that consist of multiple heat sources spread over a surface have been developed for many years. Generally, the expression ability is determined by the number of actuators in actuator arrays, and accordingly, thermal displays require many heat sources to ensure a high spatial resolution of temperature distribution. However, the number of usable heat sources is limited because of mechanical issues. In order to solve this problem, a control method that employs a model derived from a thermal diffusion equation and is used between two heat sources, is proposed in this paper. By using the proposed method, any selected point of the heat conduction can be expressed using only one heat source. Therefore, infinite number of nodes of propagation can be reproduced by selecting a desired node. The method is expected to extend the technology for controlling multiple actuators or heat sources on a surface.
IEEJ Journal of Industry Applications, 2015
Automatika ‒ Journal for Control, Measurement, Electronics, Computing and Communications, 2013
Proceedings of Sice Annual Conference 2010, Aug 1, 2010
Recently, to enhance the reality of remote or multimedia communication, research about the transm... more Recently, to enhance the reality of remote or multimedia communication, research about the transmission of tactile information which is called haptics has been developing. Haptic information consists of several elements such as sense of force, surface touch, or thermal sensation. As for the thermal sensation on which this paper focuses, it is important to know the amount of the heat inflow, which is defined in this paper as a heat flowing into a thermal device from outside. A heat flux sensor is generally used for the obtainment of the information. However, the heat flux sensor absorbs the heat because the sensor itself has a thermal capacitance. As a result, in a transient state of the thermal system, the information of heat inflow is altered and the accurate information is not fed back to the controller. This paper proposes a heat inflow observer, which is based on a disturbance observer and estimates the information of heat inflow. By the proposed method, the value of heat inflow information is fed back to the controller, and it is possible to control the heat inflow. The heat inflow control can be used for the transmission of thermal sensation. Several experiments are conducted to see the validity of the observer and the heat inflow control.
IEEJ Journal of Industry Applications, 2015
IEEJ Journal of Industry Applications, 2015
IEEJ Journal of Industry Applications, 2013
IEEE Transactions on Industrial Electronics, 2012
ABSTRACT The 30 papers in this special section focus on industrial applications and implementatio... more ABSTRACT The 30 papers in this special section focus on industrial applications and implementation issues associated with Kalman filters.
IEEE Transactions on Industrial Electronics, 2013
Energies
This paper proposes a new estimation algorithm based on the Luenberger observer methodology and m... more This paper proposes a new estimation algorithm based on the Luenberger observer methodology and multilayer concept. The proposed multi-layer Luenberger observer (MLO) is implemented in the control structure designated for a two-mass system. Two types of aggregation mechanism are evaluated in the paper. The MLO ensures better estimation quality of the mechanical state variables: motor speed, shaft torque, load speed and load torque, as compared to the classical single observer. The more accurate estimated states, the more precise closed-loop control is guaranteed. MLO is designated for the system where initial conditions of the plant are not known or the state variables can change rapidly (load torque in the considered case). The estimation algorithm and control strategy is evaluated through simulation and experimental tests. The obtained results confirm efficiency of the proposed MLO.
2021 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM), 2021
Under industrial scenarios, high-speed motion is an important factor in increasing productivity. ... more Under industrial scenarios, high-speed motion is an important factor in increasing productivity. In this paper, a linear variable structured elastic actuator (LVSEA) is proposed for high-speed linear motion. The LVSEA consists of a geared motor, an electromagnetic clutch, a ball screw, compression springs, and a flange. The clutch is located between the geared motor and the ball screw. The clutch disconnects the geared motor from the ball screw. The compression springs are located between a housing and the flange of the ball screw. The spring stores elastic energy using the geared motor via the ball screw and the clutch. The stored elastic energy is released as kinetic energy by disconnecting the ball screw from the geared motor. On the load side, low inertia and low friction are achieved by disconnecting the ball screw from the geared motor, and high-speed movement is thereby realized. In the experiment, the velocity of a conventional ball screw system driven by the geared motor wa...
Robust walking under various ground condition is required for application of biped robots. Some r... more Robust walking under various ground condition is required for application of biped robots. Some researches deal with the biped robot control considering foot slip as [1] and [2]. However, few research deal with recovery control after slip. Our work presents balance recovery trajectory design and disturbance-observer (DOB) based control [3]. Balance recovery trajectory is designed through slip recovery gait of human [4]. DOB requires only nominal model, and realizes a precise and robust control system [5].
2017 IEEE 26th International Symposium on Industrial Electronics (ISIE), 2017
This paper proposes a force feedback compliance force lock for biltateral control based on sensor... more This paper proposes a force feedback compliance force lock for biltateral control based on sensor-less sensor Reaction Force Observer (RFOB). The force limit is defined by the operator in advance based on the experience. The force lock protects the object which is in contact with the slave actuator from excessive force imposed by the master operator in bilateral control. A small vibration has been introduced to notify the attainment of the force limit to the master operator. Furthermore, if master operator wishes to increase his applied force, he will experience spring effect. The equilibrium point of virtual spring controller which is continuously copied from the slave force locked position aligns master and slave positions at force lock mode. The loss of reaction force occurs at the transition from bilateral control to force lock and vice versa has been removed to regain system stability and to facilitate comfortable operation for the operator. Releasing logic of force lock can be...
IEEE Journal of Emerging and Selected Topics in Industrial Electronics
The expansion of the applicable range of robots and machines requires the ability to cooperate wi... more The expansion of the applicable range of robots and machines requires the ability to cooperate with humans and adapt to external environments. It is necessary to use torque information in order to achieve these capabilities. A reaction torque observer is one of the effective methods to obtain torque information because it does not need a torque sensor and it can deal with torque information in the high-frequency domain. However, it needs a correct compensator to reject disturbances to estimate the precise torque. Generally, the disturbance compensator of the reaction torque observer is derived by manual model selection and manual/automatic parameter fitting. This method not only takes time and effort but also does not always obtain an optimal solution because it depends on a predetermined model. In particular, it is well known that nonlinear elements such as friction are difficult to model. To overcome this issue, an automatic design method of a disturbance compensator is proposed in this article. The compensator is abstracted automatically using an element description method. Using the element description method, model design in advance is not needed because the model selection and the parameter fitting are conducted simultaneously. Therefore, the element description method can be applied to systems whose model structure is unknown. In addition, it is possible to input human intentions as initial settings. These features enable designs that make use of human knowledge and the computational power of computers.
IEEE Open Journal of the Industrial Electronics Society
In this study, a method for realizing an intelligent production process by reducing quality varia... more In this study, a method for realizing an intelligent production process by reducing quality variation in the manufacturing industry is proposed. A quality fluctuation model in a production process is abstracted, and the quality is improved using adaptation rules based on the model. In this framework, the value directly related to product quality is expressed as multiplying the coefficient and the setting parameter. This expression makes it possible to regard the quality variations as being caused by the coefficient variations. Hence, it is possible to reduce the variation of quality by predicting the fluctuation of the coefficient from various data acquired from the production line and increasing or decreasing the setting parameter based on the predicted value. Moreover, the element description method is applied to predict the fluctuation of the coefficient. The element description method has the advantages of a model-based method whose physical meaning can be understood and the advantages of a database method applicable to an unknown system. Therefore, the mechanism of fluctuation can be abstracted and can be used as explicit knowledge. In this study, this framework is applied to reduce the variation in filling weight of the powder filling process and is demonstrated. As a result, the filling weight variation has been reduced by approximately 33 %.
IEEE/ASME Transactions on Mechatronics
Electrical Engineering in Japan
IEEE Transactions on Industrial Electronics
Motion control is a fundamental technique used in automated mechanical systems. Classically, velo... more Motion control is a fundamental technique used in automated mechanical systems. Classically, velocity, force, and impedance are controlled in motion control systems, but simultaneous control is difficult. This study proposes periodic/aperiodic (P/A) motion control based on periodicity and aperiodicity of motion. The P/A motion control separately applies different control methods to P/A motions using P/A velocity and P/A force, which are extracted using a periodic/aperiodic separation filter (PASF) from velocity and force. Accordingly, six types of P/A motion controls are constructed in this study, which correspond to different combinations of the P/A velocity, P/A force, and P/A impedance controls. To construct the P/A motion control systems, acceleration control based on a disturbance observer is used. The acceleration control system, which rejects disturbances, enables the P/A motion control design to ignore disturbances. The experiments were conducted to validate the six P/A motion controls, which simultaneously realized two P/A motion control objectives.
IEEE Transactions on Industrial Informatics
Repetitive operations are widely conducted by automatic machines in industry. Periodic disturbanc... more Repetitive operations are widely conducted by automatic machines in industry. Periodic disturbances induced by the repetitive operations must be compensated to achieve precise functioning. In this paper, a periodic-disturbance observer (PDOB) based on the disturbance observer (DOB) structure is proposed. The PDOB compensates a periodic disturbance including the fundamental wave and harmonics by using a time delay element. Furthermore, an adaptive PDOB is proposed for the compensation of frequency-varying periodic disturbances. An adaptive notch filter (ANF) is used in the adaptive PDOB to estimate the fundamental frequency of the periodic disturbance. Simulations compare the proposed methods with a repetitive controller (RC) and the DOB. Practical performances are validated in experiments using a multi-axis manipulator. The proposal provides a new framework based on the DOB structure to design controllers using a time delay element.
Uploads
Papers by Seiichiro Katsura