急！急！非常急！麻烦各位英语牛人帮忙啊！！！翻译下面这几段的机械类的英语，在线等，在线等，急用！
要求： 要比较专业的翻译，不要用机器翻译的，谢谢啦~~~~~~
4.1.3. Complementary digital structures
In the block diagram shown in Fig. 5, other complementary blocks to the overall controller system were developed under VHDL. Next, a summary of these complementary blocks follows. The profile generator is an independent computational unit based on accumulation,which can be reconfigured, using the FPGA flexibility, to provide the desired motion profile. This module has a multiplexor and data register that receives the speed profile parameters, which feed the accumulator to generate the motion profile, controlled by a finite-state machine.
Position profile is generated by integrating the speed profile with another accumulator.
A 32-bit digital adder is used for the adding point at the control loop. Another necessary element for the controller is a digital to analog converter (DAC) that gives the control signal to the servo amplifier. For this work a 16-bit Burr Brown (1998) DAC8531 is used. This converter has a serial interface and a state machine is used to provide the driving signals from the controller to the physical DAC device.
4.2. Servo system model identification
The controller design requires knowledge of the system dynamics or in other words, it is required to have a model.The model is obtained in two parts: the first is the identification of the elements: amplifier, servomotor and encoder, by computational methods; and the second is the gain computation of the DAC and the zero-order hold(ZOH) sampler.
4.2.1. Recursive least-square method
The computational identification methods have been evolving throughout the last few years as the best choice to obtain a system model. There are different identification methods that have been proven, obtaining the best results with recursive methods, in this specific case, recursive least square. The recursive least-square method was programmed in C++, according to Aguado and Martinez(2003), using an algorithmic form based on (2), where C(t)is the covariance estimation matrix, j is the exponential omission coefficient, on the other hand, the matrix g(t) (3) is the product between the measurement matrix z(t) and the estimate covariance C(t), where a2 is a constant determined by (4). The identified model is described by (5). The identification of the model includes the servomotor,amplifier and encoder:
（公式省略）
4.2.2. DAC and ZOH models
A DAC is characterized by its resolution n, it varies typically between 8 and 16 bits and the common output interval is ±10 V, which is the input range for most servo amplifiers. In this work, a 16-bit converter is used with output voltage ranges of ±10 V. The DAC gain is represented by the following equation:
（公式略）