A position-based impendence control structure using fuzzy neural networks is proposed in this paper. It modifies the reference position according to the force error so that contact force between the manipulator and the environment can track the reference force.

Using 6 DOFs force/torque sensor,the cartesian position based impedance control of single finger is implemented. According to the force/torque sensing information of the fingertip sensor,reference position will be modified in term of aim impedance model,and the inner position controller is used to control the finger to follow anticipant track.

The experiment results show that the proposed controller provides good performance in case of disturbance rejection and parameter mismatch and the position signal tracked the reference position quickly and smoothly.

In this paper, the gradient is determined in the center of four neighboring meshes using a polynomial approximation of the displacement function in a reference position.

Despite the deliberately large deviations from the reference position, the changes in TRP and TIS are generally within ±0.5 dB with a maximum of about 1.4 dB.

Radiation patterns of six handsets have been measured while they were mounted at various offsets from the reference position defined by the Cellular Telecommunications >amp;amp; Internet Association (CTIA) certification.

The difficulty in such a case is that both the query and the data objects change positions continuously, and therefore we can not rely on a given fixed reference position to determine the answer.

A desirable feature in spatio-temporal databases is the ability to answer future queries, based on the current data characteristics (reference position and velocity vector).

During his visit to Beijing, G. R. Burbidge reaffirmed their view point: the statistical distribution of observed number of QSOs versus it's redshift (figure of N-Z) has three peaks nearly at Z≈0.5, 1.5, 2.0 (ef. Fig. 1). Though their statistical analysis based directly on the observation is model-independence, it has no apparent physical meaning. In order to give physical meaning to the relevant quantities, it is necessary to have recourse to cosmological model. Basing on Friedman's model, we have done the...

During his visit to Beijing, G. R. Burbidge reaffirmed their view point: the statistical distribution of observed number of QSOs versus it's redshift (figure of N-Z) has three peaks nearly at Z≈0.5, 1.5, 2.0 (ef. Fig. 1). Though their statistical analysis based directly on the observation is model-independence, it has no apparent physical meaning. In order to give physical meaning to the relevant quantities, it is necessary to have recourse to cosmological model. Basing on Friedman's model, we have done the statistical analysis of 1467 QSOs collected in Burbidge's catalog, then obtained the luminosity evolutionary law of QSOs and the statistical distribution of its number versus the luminosity distance.In Friedman's model, the redshift is naturally related to the luminosity distance:Here H0 is Hubble 's constant, and q0 the deacceleration parameter. Considering that it is recently discoved that the neutrino has rest mass, we only take account of two typical quantities of q0: i.e. q0= + 1 (closed universe) and q0 = 1/2 (flat universe).The vertical axis N in Fig. 1 represents the observed number of QSOs (apparent magnitude m≤21). In order to obtain the distribution of actual number (relative ratio), we must do some reasonable correction. According to the relation between apparent magnitude and luminosity distance :m = M + 5 log dL ?5. (2)we know that the more distant the QSOs are, the less the observed number of QSOs is Therefore, we ought to do number counting after removing all of QSOs at the same distant. Because there are a few of QSOs with largest redshift (Z≈3.5) in Burbidge's catalog, the reference position is chosen at Z=3.0. The apparent magnitude of QSOs after removing them to the position corresponding to Z= 3.0 is called "reduced magnitude" m'. From Bq. (2), we haveSince there is only one of QSOs which m' > 21 in the catalog, we choose the visual limit as 21. If m' < 21, it is counted ; if m' > 21, it is not counted.In addition, we must take acount of luminosity evolution. We must analyse statistically the luminosity distribution of QSOs at different intervals of Z. At first, we count the number of QSOs within the intervals Am = 0.5 and AZ = 0.05. Then, we draw the figures of normalized number counting versus apparent magnitude (cf. Fig. 2). The result reveals that all of Figs. N/Nmax--m at different Z are appeared to have the same shape (normal distribution), especially appear a common peak at m≈1819 (except for Z < 0.3). This suggests that the luminosity evolution of QSOs just compensates the decrease of it's luminosity with distance, so that the apparent magnitude of QSOs at different distance appear the same distribution.Hence, if we take m in Eq. (3) as correspondent constant, and substitute Eq. (1) into Eq. (3), we would obtained the relation between the reduced magnitude of QSOs and redshift Z. For the QSOs at peak, this relation is more accurate, and is written as following:(i) for q0= 1,m = 5 log 3/Z + 18 (4a)(ii) for q0= 1/2, In Friedman's model, it is easily to derive the relations between cosmological time t and redshift Z as following:(i) for q0 = 1,(ii) for q0 = 1/2,Combining the Bqs. (4a, b) and (5a, b), we ultimately obtained the evolutionary law of reduced magnitude of QSOs at peak. For the case of q0 = 1/2, we haveThe curves shown in Fig. 3 represent the theoretical formula above obtained, in which the vertical line segments represent the observed peaks of reduced magnitude of QSOs at different, Z (the interval is chosen as 0.05). The corresponding t are marked in the horizontal axis. (II0 is chosen as 100 km/see kpe.) It is apparent that the observed data is well fit. to the theoretical curves.Because the luminosity evolution of QSOs just compensates the decrease of its luminosity with distance, the observed number of QSOs is also its actual number (relative ratio). The intended correction mentioned at begining is not necessary. Therefore, it is concluded that the Fig. 1 given by Burbidge also represents the actual number distribution of QSOs versus its luminosity distance, provided that

Cant and erosslevel are two basic items for the track measurement. This cant measuring device which is successfully developed in our country, comprises a single axis vertical platform established by a floated rate-lntegrating gyroof single degree of freedom and a floated pendulous accelerometer, so that it will keeping in a true vertical reference position in the car-body. The rate gyro is to be used to obtain the angular velocity of turning and the travelling speed is obtained from the taehogenerator....

Cant and erosslevel are two basic items for the track measurement. This cant measuring device which is successfully developed in our country, comprises a single axis vertical platform established by a floated rate-lntegrating gyroof single degree of freedom and a floated pendulous accelerometer, so that it will keeping in a true vertical reference position in the car-body. The rate gyro is to be used to obtain the angular velocity of turning and the travelling speed is obtained from the taehogenerator. Through an analog multiplier signals for compensation of invariance it gives to the platform so that the effects of centrifugal acceleration is overcome. This paper is intended to describe in detail the measurement technology of the device, the design and analysis of the servo-loop, the horizontal control loop and the compensation of invariance for centrifugal acceleration, the cant calculation and demodulation, as well as the measurement and analysis on the actual tracks.

The control system design for a parallel inverted pendulum on an inclined rail has been successfully implemented. The control law includes the integration term which not only eliminates the constant disturbance due to the inclined rail but also assures the cart of following the given reference position. Theoretical analysis of the pendulum system and the control results are given.