搜搜考试网求助机械文献翻译第二篇
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求助机械文献翻译第二篇
The estimated cutting force and the feedrate are the controlled output and the control input, respectively. Three control strategies are employed for the turning force control. The first strategy is based on the PI controller which is designed from a nominal dynamic model. The second strategy for the turning force control adopts a variable gain adaptive control using the estimated cutting force. In this case the estimated force signal is considered as the true value and used for identifying the model parameters. The adaptive control with constraint approach is used to improve the stability and the performance.
A fuzzy logic controller (FZC) is designed for the last control strategy because the dynamic relation between the cutting force and the feedrate is too complex to be described in a nominal model. The fuzzy logic rule is designed based on a series of the cutting tests and is formed into the standard PI fuzzy control. All three control strategies as well as the synthesized cutting force monitor are constructed into a computer integrated CNC lathe. For each control strategy, the control performance is compared between using the measured cutting force and using the estimated cutting force signals.3. CUTTING FORCE MONITORING On-line and real-time information of the cutting force signal is the key factor for the turning force control. A cutting force monitoring system based on the AC spindle drive was presented before by the authors [4]. They derived a dynamic model of the AC spindle drive and estimated the cutting force on-line using the measured power signal. Even if their estimation results at the steady state coincide with the measured signals within 3% error, the estimated force at the transient state showed a time lag of about 0.3 second. The time lag in sensing the controlled variable is the serious limitation for the control performance. It turns out that the time lag is mainly due to the time delay of the measured output power signal, which, in turn, results in the time delay in the output torque of the AC motor because the motor torque is calculated simply by dividing the output power by the motor speed.
In this section, a new synthesized cutting force monitoring method is proposed to improve the transient estimation performance. Because the main reason for the time lag is the insufficient sensing of the motor output power, another method to quickly obtain the motor torque is pursued using the AC motor characteristics. Calculation Of The Motor Output Torque The output torque of the AC induction motor is activated due to the interaction between the stators's rotating magnetic field and the rotor's inducted currents and can be expressed in terms of the rotor input power and the synchronous speed.where w, is the synchronous speed of the AC motor. The rotor input power is the difference between the electrical input power and the power losses in the stator windings.
For the delta-connected balanced load, the phase voltage is equal to the line voltage but the line current should be divided by ,13 to obtain the phase current. In general, the input power of the AC motor can be obtained in terms of the root-mean-square values of the phase voltage and the phase current.It is assumed that the spindle motor rotates at the constant speed in turning process and the slip ratio is close to zero except at the moment when the cutting starts. Thus the output torque of Eq (l) can be approximated as().where wM is the motor speed. When the cutting starts or when the calculated electric power in Eq (2) increases abruptly, the slip ratio should be taken care of in Eq (1) instead of Eq.
The estimated cutting force and the feedrate are the controlled output and the control input, respectively. Three control strategies are employed for the turning force control. The first strategy is based on the PI controller which is designed from a nominal dynamic model. The second strategy for the turning force control adopts a variable gain adaptive control using the estimated cutting force. In this case the estimated force signal is considered as the true value and used for identifying the model parameters. The adaptive control with constraint approach is used to improve the stability and the performance.
A fuzzy logic controller (FZC) is designed for the last control strategy because the dynamic relation between the cutting force and the feedrate is too complex to be described in a nominal model. The fuzzy logic rule is designed based on a series of the cutting tests and is formed into the standard PI fuzzy control. All three control strategies as well as the synthesized cutting force monitor are constructed into a computer integrated CNC lathe. For each control strategy, the control performance is compared between using the measured cutting force and using the estimated cutting force signals.3. CUTTING FORCE MONITORING On-line and real-time information of the cutting force signal is the key factor for the turning force control. A cutting force monitoring system based on the AC spindle drive was presented before by the authors [4]. They derived a dynamic model of the AC spindle drive and estimated the cutting force on-line using the measured power signal. Even if their estimation results at the steady state coincide with the measured signals within 3% error, the estimated force at the transient state showed a time lag of about 0.3 second. The time lag in sensing the controlled variable is the serious limitation for the control performance. It turns out that the time lag is mainly due to the time delay of the measured output power signal, which, in turn, results in the time delay in the output torque of the AC motor because the motor torque is calculated simply by dividing the output power by the motor speed.
In this section, a new synthesized cutting force monitoring method is proposed to improve the transient estimation performance. Because the main reason for the time lag is the insufficient sensing of the motor output power, another method to quickly obtain the motor torque is pursued using the AC motor characteristics. Calculation Of The Motor Output Torque The output torque of the AC induction motor is activated due to the interaction between the stators's rotating magnetic field and the rotor's inducted currents and can be expressed in terms of the rotor input power and the synchronous speed.where w, is the synchronous speed of the AC motor. The rotor input power is the difference between the electrical input power and the power losses in the stator windings.
For the delta-connected balanced load, the phase voltage is equal to the line voltage but the line current should be divided by ,13 to obtain the phase current. In general, the input power of the AC motor can be obtained in terms of the root-mean-square values of the phase voltage and the phase current.It is assumed that the spindle motor rotates at the constant speed in turning process and the slip ratio is close to zero except at the moment when the cutting starts. Thus the output torque of Eq (l) can be approximated as().where wM is the motor speed. When the cutting starts or when the calculated electric power in Eq (2) increases abruptly, the slip ratio should be taken care of in Eq (1) instead of Eq.
The estimated cutting force and the feedrate are the controlled output and the control input, respectively. Three control strategies are employed for the turning force control. 估计的切削力和进刀速度分别是受控的输出和控制输入.对于车削力的控制采用了三种控制策略.The first strategy is based on the PI controller which is designed from a nominal dynamic model.第一种策略基于比例积分（PI）控制器,它是由标称动态模型设计的. The second strategy for the turning force control adopts a variable gain adaptive control using the estimated cutting force. 第二种用于车削力控制的策略采用一种可变增益自适应控制,它是利用估计的切削力.In this case the estimated force signal is considered as the true value and used for identifying the model parameters. 在这种情况下,估计的切削力信号被看作是真实的值,并被用于鉴别模型的参数.The adaptive control with constraint approach is used to improve the stability and the performance. 有限制的自适应控制（ACC）法可用于改善稳定性和性能.
A fuzzy logic controller (FZC) is designed for the last control strategy because the dynamic relation between the cutting force and the feedrate is too complex to be described in a nominal model. （我们）设计了一台模糊逻辑控制器（FZC）用于第三种控制策略,因为切削力和进刀速度之间的动态关系太复杂了,以致无法用通常的模型加以描述.The fuzzy logic rule is designed based on a series of the cutting tests and is formed into the standard PI fuzzy control.模糊逻辑的规则根据一系列切削实验设计,并被形成为标准的PI模糊控制. All three control strategies as well as the synthesized cutting force monitor are constructed into a computer integrated CNC lathe. 所有这三种控制策略以及合成的切削力监控器都被构建到一台集成计算机的CNC车床上.For each control strategy, the control performance is compared between using the measured cutting force and using the estimated cutting force signals.对于每一种控制策略来说,都在两种情况下进行了对比,一种是采用了实测的切削力,另一种是采用的估计切削力信号.3.CUTTING FORCE MONITORING
3. 切削力监控
On-line and real-time information of the cutting force signal is the key factor for the turning force control. 切削力信号的在线信息和实时信息是车削力控制的关键因素.A cutting force monitoring system based on the AC spindle drive was presented before by the authors [4]. 作者以前已介绍过一种基于AC（交流）主轴传动的切削力监控系统【4】.They derived a dynamic model of the AC spindle drive and estimated the cutting force on-line using the measured power signal. 它们能在线利用实测的功率信号,导出AC主轴传动的动态模型和估计的切削力.Even if their estimation results at the steady state coincide with the measured signals within 3% error, the estimated force at the transient state showed a time lag of about 0.3 second. 即使它们在稳态下的估计结果与实测信号的一致性在3％的误差以内,但在瞬态时的估计切削力呈现约0.3秒的时间滞后.The time lag in sensing the controlled variable is the serious limitation for the control performance. 在传感受控变量中的时滞对控制性能是严重的限制.It turns out that the time lag is mainly due to the time delay of the measured output power signal, which, in turn, results in the time delay in the output torque of the AC motor because the motor torque is calculated simply by dividing the output power by the motor speed. 其结果是,时滞主要是由于实测输出功率信号的时间延迟引起的,它反过来导致AC电机输出转矩的时间延迟,因为电机转矩是将输出功率除以电机速度来计算的.
In this section, a new synthesized cutting force monitoring method is proposed to improve the transient estimation performance. 在本小节中,提出了一种新的合成的切削力监控方法,以改善瞬态估计性能.Because the main reason for the time lag is the insufficient sensing of the motor output power, another method to quickly obtain the motor torque is pursued using the AC motor characteristics. 因为时滞的主要原因是对电机输出功率传感的不充分,所以（我们）寻求另一种利用AC电机特性迅速获得电机转矩的方法.
Calculation Of The Motor Output Torque
电机输出转矩的计算
The output torque of the AC induction motor is activated due to the interaction between the stators's rotating magnetic field and the rotor's inducted currents and can be expressed in terms of the rotor input power and the synchronous speed. AC感应电机的输出转矩是由于定子的旋转磁场和转子的感生电流之间相互作用而引起的,而且可以用转子输入功率和同步转速来表达.where w, is the synchronous speed of the AC motor. The rotor input power is the difference between the electrical input power and the power losses in the stator windings.式中,W为AC电机的同步转速.转子输入功率是输入电功率和定子绕组中功率损耗之差值.
问题补充：For the delta-connected balanced load, the phase voltage is equal to the line voltage but the line current should be divided by ,13 to obtain the phase current.对于三角形连接的平衡负荷来说,相位电压等于线路电压,但线路电流应除以13才能得到相位电流. In general, the input power of the AC motor can be obtained in terms of the root-mean-square values of the phase voltage and the phase current.一般来说,AC电机的输入功率可以用相位电压和相位电流的均方根值得到.It is assumed that the spindle motor rotates at the constant speed in turning process and the slip ratio is close to zero except at the moment when the cutting starts. 我们假设,主轴电机在车削过程中以恒定的转速旋转,除了在切削开始的瞬间,滑移率接近于零.Thus the output torque of Eq (l) can be approximated as().where wM is the motor speed. When the cutting starts or when the calculated electric power in Eq (2) increases abruptly, the slip ratio should be taken care of in Eq (1) instead of Eq.因此,式（1）的输出转矩可以近似为（……）.式中,mW是电机转速.当切削开始时,或者式（2）中计算的电功率突然增加时,式（1）中而不是式（×）
中的滑移率应予以注意.
A fuzzy logic controller (FZC) is designed for the last control strategy because the dynamic relation between the cutting force and the feedrate is too complex to be described in a nominal model. （我们）设计了一台模糊逻辑控制器（FZC）用于第三种控制策略,因为切削力和进刀速度之间的动态关系太复杂了,以致无法用通常的模型加以描述.The fuzzy logic rule is designed based on a series of the cutting tests and is formed into the standard PI fuzzy control.模糊逻辑的规则根据一系列切削实验设计,并被形成为标准的PI模糊控制. All three control strategies as well as the synthesized cutting force monitor are constructed into a computer integrated CNC lathe. 所有这三种控制策略以及合成的切削力监控器都被构建到一台集成计算机的CNC车床上.For each control strategy, the control performance is compared between using the measured cutting force and using the estimated cutting force signals.对于每一种控制策略来说,都在两种情况下进行了对比,一种是采用了实测的切削力,另一种是采用的估计切削力信号.3.CUTTING FORCE MONITORING
3. 切削力监控
On-line and real-time information of the cutting force signal is the key factor for the turning force control. 切削力信号的在线信息和实时信息是车削力控制的关键因素.A cutting force monitoring system based on the AC spindle drive was presented before by the authors [4]. 作者以前已介绍过一种基于AC（交流）主轴传动的切削力监控系统【4】.They derived a dynamic model of the AC spindle drive and estimated the cutting force on-line using the measured power signal. 它们能在线利用实测的功率信号,导出AC主轴传动的动态模型和估计的切削力.Even if their estimation results at the steady state coincide with the measured signals within 3% error, the estimated force at the transient state showed a time lag of about 0.3 second. 即使它们在稳态下的估计结果与实测信号的一致性在3％的误差以内,但在瞬态时的估计切削力呈现约0.3秒的时间滞后.The time lag in sensing the controlled variable is the serious limitation for the control performance. 在传感受控变量中的时滞对控制性能是严重的限制.It turns out that the time lag is mainly due to the time delay of the measured output power signal, which, in turn, results in the time delay in the output torque of the AC motor because the motor torque is calculated simply by dividing the output power by the motor speed. 其结果是,时滞主要是由于实测输出功率信号的时间延迟引起的,它反过来导致AC电机输出转矩的时间延迟,因为电机转矩是将输出功率除以电机速度来计算的.
In this section, a new synthesized cutting force monitoring method is proposed to improve the transient estimation performance. 在本小节中,提出了一种新的合成的切削力监控方法,以改善瞬态估计性能.Because the main reason for the time lag is the insufficient sensing of the motor output power, another method to quickly obtain the motor torque is pursued using the AC motor characteristics. 因为时滞的主要原因是对电机输出功率传感的不充分,所以（我们）寻求另一种利用AC电机特性迅速获得电机转矩的方法.
Calculation Of The Motor Output Torque
电机输出转矩的计算
The output torque of the AC induction motor is activated due to the interaction between the stators's rotating magnetic field and the rotor's inducted currents and can be expressed in terms of the rotor input power and the synchronous speed. AC感应电机的输出转矩是由于定子的旋转磁场和转子的感生电流之间相互作用而引起的,而且可以用转子输入功率和同步转速来表达.where w, is the synchronous speed of the AC motor. The rotor input power is the difference between the electrical input power and the power losses in the stator windings.式中,W为AC电机的同步转速.转子输入功率是输入电功率和定子绕组中功率损耗之差值.
问题补充：For the delta-connected balanced load, the phase voltage is equal to the line voltage but the line current should be divided by ,13 to obtain the phase current.对于三角形连接的平衡负荷来说,相位电压等于线路电压,但线路电流应除以13才能得到相位电流. In general, the input power of the AC motor can be obtained in terms of the root-mean-square values of the phase voltage and the phase current.一般来说,AC电机的输入功率可以用相位电压和相位电流的均方根值得到.It is assumed that the spindle motor rotates at the constant speed in turning process and the slip ratio is close to zero except at the moment when the cutting starts. 我们假设,主轴电机在车削过程中以恒定的转速旋转,除了在切削开始的瞬间,滑移率接近于零.Thus the output torque of Eq (l) can be approximated as().where wM is the motor speed. When the cutting starts or when the calculated electric power in Eq (2) increases abruptly, the slip ratio should be taken care of in Eq (1) instead of Eq.因此,式（1）的输出转矩可以近似为（……）.式中,mW是电机转速.当切削开始时,或者式（2）中计算的电功率突然增加时,式（1）中而不是式（×）
中的滑移率应予以注意.