【正文】 Jacobson, ,Readout supervisor design specifications[M], LHCb [16], report on the RD12 project:timeing,trigger and control system for LHC detectors[J] Time and technology,2009，(3):152155附錄A 英文文獻(xiàn)原文Development of a Novel Drive Topology for a Five Phase Stepper Motor. Weerakoon and L. Samaranayake（Dept. of Electrical and Electronic Engineering, Faculty of Engineering, University of Peradeniya, Sri Lanka）[Abstract] In this paper, a novel drive topology for a five phase stepper motor is described in detail. Commercially off the shelf, low cost, standard stepper motor drive ICs are used to derive a novel drive topology for five phase stepper motors which enables closed loop speed and position control powered by inner current control loop. It is proved that the derived topology can be generalized to any stepper motor with higher odd number of phases. The designed driver consists of full step, half step, clockwise and counter clockwise drive modes with the speed control and current control. [key words] Fivephase stepper motor, the return drive, speed control, multimodeI. INTRODUCTIONIn most of the robotics and automation engineering designs various types of stepper motors are used to obtain the required motion profiles. Stepper motors are preferred, as they do not require frequent maintenance and due to their ability to operate in many harsh environments. Selection of the motors and their drive circuits depend on the required performance characteristics of the applications. The two phase and four phase stepper motors are the most mon types available in the market.However, for applications requiring high precision, low noise and lower vibration, Five Phase Stepper Motors are used. Due to smaller step angle, five phase stepper motors offer higher resolution, lower vibration and higher accelerations and decelerations. Therefore it is essential to make sure that these motor characteristics can be obtained from the designed drive topology.Because the five phase stepper motors are a rarely used type in the robotic applications and the construction is typically plicated, it is very difficult to find driver ICs, which are manufactured exclusive for them. As a result, the available Driver circuits for five phase stepper motors are very expensive.Using the available drive control ICs manufactured for mon kinds of stepper motors such as 2 phased and 4 phased and using them in modeling new driver topology for other stepper motors would be a cost effective approach.The IC L297 integrates all the control circuitry required to control bipolar and unipolar stepper motors. The L298N dual H bridge drive forms a plete microprocessor to stepper motor interface. Here, novel drive topology is investigated and developed for five phase stepper motors by adding a microprocessor and logical control system with L297 and L298N. The plete topology is described in this paper.Section II explains the ponent characteristics. Section III is on the control logic circuit design phenomena. The interface design is given in Section IV with results in Section V. Finally the conclusions are presented in Section VI.II. CHARACTERISTIC ANALYSIS OF MAIN COMPONENTSThe IC L297 can be used with an H bridge driver IC for motor drive applications as shown in . In this design H bridge function is achieved from the L298N or L293E. This may change depending on the power rating of the motor. The control signals to the L297 may be received from microcontroller or from external switches. A single IC can drive a 2 phase bipolar permanent magnet motor, a 4 phase unipolar permanent magnet motor or a 4 phase variable reluctance motor. Because very few electronic ponents are used, it has many advantages such as lower cost, higher reliability and the ability to house in a paratively smaller space. The L297 generates three modes of phase sequences, namely half step mode, full step mode and wave mode depending on the input signals it receives. Fig. Circuit diagram to drive a 2 phase bipolar or 4 phaseunipolar stepper motor using L297 and L298N ICsA． CURRENT CONTROLSmall stepper motors generally need small DC supplies that control the winding currents and they are limited by the winding resistances. On the other hand, motors with the larger rated torque values have windings with smaller resistances. Therefore, they require a controlled current supply.The L297 provides load current control in the form of two Pulse Width Modulation (PWM) chopper circuits and each chopper circuit consists of a parator, a flipflop and an external sensing resistor.In this method, while the motor current is increasing, the control system applies the supply voltage to the motor. When the current is reached up to the threshold, the control system tries to maintain the current at the desired value by changing the duty ratio of the voltage supply as shown in . For each chopper circuit, the duty ratio (D) of the voltage supply to the motor is defined as:D = Ton / (Ton + Toff),where the Ton and Toff are switch on and off durations respectively of the H bridge.In the chopper circuit, the flipflop is set by each pulse from the oscillator, enabling the output and allowing the load current to increase. As it increases the voltage across the sensing resistor increases and when this voltage reaches Vref the flipflop is reset, disabling the output until the next oscillator pulse arrives. In this method Vref determines the peak load current.The L298N is a monolithic circuit contains two H bridges. In addition, the emitter connections of the lower transistors are brought out to external terminals allowing the connection of current sensing resisters.Fig. Circuit containing the flipflop, the oscillator and the parator used for current controllingB. CURRENT CONTROL IN INHIBIT CHOPPER MODEInhibit chopper control mode and phase line chopper control mode are two of