Torque sensorless control in multidegree-of-freedom manipulator

A torque sensorless control for a multi-degree-of-freedom manipulator is described. In the method, two disturbance observers are applied to each joint. One is used to realize a robust motion controller. The other is used to obtain a sensorless torque controller. A robust acceleration controller based on the disturbance observer is shown. To obtain the sensorless torque control, it is necessary to calculate the reaction torque when the mechanical system performs a force task. The calculation method for the reaction torque is explained. Then the method is expanded to workspace force control in the multi-degree-of-freedom manipulator. Several experimental results are shown to confirm the validity of the proposed sensorless force controller     

Prognostic factors of primary liver cancer

To investigate the prognostic factors of primary liver cancer (PLC) and improve the long-term results, 1,248 cases of PLC were analysed. Univariate analysis demonstrated that discovery approach, staging of PLC, original gamma-GPT, resection, radical resection, original AFP, tumor size, tumor number, and tumor capsule have very significant effects on prognosis of PLC (all P < 0.001); cirrhosis, HBsAg, local resection, and tumor embolus in portal vein were also significant difference (all P < 0.05); age, sex, original AFP, hepatitis, and differentiation of PLC cells were no significant difference (all P > 0.05). Multivariate analysis demonstrated that original gamma-GPT, radical resection, tumor size, and tumor number were the most significant prognostic factors (all P < 0.001). Some aspects improving long-term survival were discussed.     

Optimization of parameters of recirculating apparatus for obtaining liquid nitrogen using mixtures

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 12, pp. 20–23, December, 1993.     

On the E.S. Pyatnitskii principle of decomposition

The main notions and facts of the geometrical decomposition theory were characterized in brief. The E.S. Pyatnitskii principle of decomposition was treated as the solution of the problem of assignment of feedback controls so that the controlled system admits a decomposition suitable for realization of the control objectives. It was hypothesized that this method of control is advisable if the complexity of the controlled system exceeds a certain limit.     

A Chamber for X-Ray Diffractometry of Gas Hydrates Samples for Pressures of Up to 700 atm

A chamber for X-ray diffractometry of gas-hydrate samples designed for operation at pressures of up to 700 atm and low temperatures is described. The leakproof character of the chamber at temperatures down to ?150°C is ensured by an Amaga-type seal with a fluoroplastic gasket pressed by disk springs. The chamber was used to study double hydrates using a synchrotron radiation source and a pressure generator based on a thermal multiplier.     

利用热管纺丝技术一步法生产FCY

利用平板型热管纺丝装置对普通高速纺丝机进行技术改造，并一步法生产出充分结晶的ＰＥＴ纤维（ＦＣＹ）。该纤维可直接用于织造，调节热管温度、热管安装位置可获得满足后道工序不同需要的ＦＣＹ。     

Monitoring the technical state of digital radioelectronic apparatus with the aid of signature analysis

This article presents the technical characteristics and a comparative analysis of the most widely used types of signature analyzers. It formulates the requirements on radioelectronic apparatus the diagnosis of which is planned with the aid of signature analyzers. Trends in the development of diagnostic apparatus using the method of signature analysis are determined.Translated from Izmeritel'naya Tekhnika, No. 7, pp. 50–54, July, 1993.