摘要在测量粘弹性体(如固体火箭发动机的推进剂药柱)应变的过程中，由于推进剂本身弹性模量小，在高过载状态下将产生大于2%，甚至20%的应变，普通的应变测量电路无法测量大应变，设计大应变测量电路对于粘弹性体应变特性的检测具有重要意义。推进剂应变测试中如果使用引线直接将测试信号连接到外部仪器，在推进剂随火箭发动机高速运动时，存在引线易折断无法采集信号或者缠绕难以安装的问题，直接影响测试的可行性。寻找这个问题的有效解决途径对于提高测试质量有着深远的影响。60924
本论文设计大应变的存储测试装置，运用双恒流源电桥实现大应变信号的调理，使用AD转换芯片AD7606采集数据，将现场采集的数据直接存储在存储芯片SDRAM内，采用FPGA控制采集和存储过程。待测试完成后回收装置，使用串口传输数据给上位机，获得测量数据和结果。此外，根据推进剂的尺寸，并考虑PCB的抗干扰、抗冲击能力，设计了装置的机械外壳。
经过模拟调试，基本实现了大应变的测试存储功能。
Abstract In measuring process of viscoelastic substance strain such as solid propellant grain, it is easy to cause more than 2% even to 20% strain because of Small elastic modulus of the material. Common strain measurement circuit can not measure large strain, and the design of large strain viscoelastic substance measurement circuit is of great significance for detecting strain characteristics. In solid propellant grain test, lead wires are common used to connect directly to the test signal to an external device, however, if propellant grain moves at a high speed, lead wires can be broken and can’t collect signal, in addition, lead wires wound difficult to install. In conclusion, looking for effective ways to solve this problem has a profound impact on improving test quality.
This article design the large strain storage testing device.Dual constant current sources are used to achieve large strain signal acquisition effectively. Use AD7606 to collect signal, and store field data directly in SDRAM memory chip under control of FPGA. Recover device after test, use serial transmit data to the host computer. According to the size of the propellant, take PCB interference, impact resistance into consideration, design the device’s mechanical casing.
Keywords large strain measurement storage test serial transmittion
目 次
1 绪论5
1.1 课题研究背景及意义5
1.3 存储测试的国内外研究现状7
1.4 论文的主要研究内容7
2 大应变存储测试装置总体方案7
2.1系统技术指标8
2.2 总体方案设计8
2.2.1 大应变信号的测量8
2.2.2 系统电路方案设计9
2.2.3 系统软件工作流程设计10
2.2.4 装置的机械外壳设计11
2.3 本章小节11
3 存储测试系统硬件电路设计12
3.1 应变信号调理电路设计12
3.1.1 应变测量电路12
3.1.2 恒流源电路13
3.1.3 放大电路14
3.2 A/D模数转换电路设计17
3.2.1 AD选型.17
3.2.2 AD电路设计.17
3.3 基于FPGA的控制电路设计18
3.3.1 FPGA选型18
3.3.2 FPGA最小系统及电路设计18
3.4 存储器电路设计20
3.4.1 存储器选型20
3.4.2 储器电路设计21
3.5 储测试装置与上位机通信电路设计21
3.5.1 通信方式选择21
3.5.2 通信电路设计21
3.6 电源设计22
3.6.1 电池选择22
3.6.2 模拟电源设计22 大应变存储测试装置设计:http://www.751com.cn/zidonghua/lunwen_66483.html