Question

在我目前的项目中，我试图通过压力和温度测量来计算高度。我已经设法将从传感器收集的三种类型的数据（温度，压力，安全带[0或1]的状态）发送到功能节点，在那里它们可以一起处理。压力和温度由两个元素组成：环境[t0，t1]，压力[pr0，pr1]。数据每2秒到达一次功能节点。

我想根据以下逻辑计算实际高度：

1）当第一个环境和压力数组到达时，我检索t0，pr0，计算初始海拔 hInit ~t0 / PR0;

2）之后，将从t1，pr1，t2，pr2 ...... tN，prN计算出的进一步高度 hChecked 将与初始高度进行比较，初始高度将给出实际高度h。 h = hChecked - hInitial ;

3）如果h < 0我们需要选择另一个初始高度，即检索并存储新的t0，pr0;

4）如果h> 3我们需要检查皮带的状态。如果1 - 状态是安全的;如果0 - 锁定腰带;

我有以下代码：

if(ambient !== null && pressure !== null && lockerState != null) {

    var hInit;
    var hChecked;
    var h;

    //p0 is the hardcoded pressure on the level of the sea
    //for the current area
    var p0 = 1019;

    //assing new variables for initital pressure and temp
    var tInit = ambient[0];
    var pInit = pressure[0];

    //variables for the checked pressure and temp
    var tChecked = ambient[1];
    var pChecked = pressure[1];

    //altitude hInit (hInit) is measure when the testbest is turned on

    hInit = (((Math.pow((p0/pInit), (1/5.257)))-1)*(tInit + 273.15))/0.0065;
    //hChecked is the measured altitude afterwards
    hChecked = (((Math.pow((p0/pChecked), (1/5.257)))-1)*(tChecked + 273.15))/0.0065;

    //h is the actual altitude the worker is working on
    h = hChecked - hInit;

    //in the case if a worker turned the testbed on 
    //when he was operating on the altitude he then
    //might go down so altitude can reduce.
    //therefore if the altitude h is < 0 we need to
    //calculate a new reference 

    if (h < 0) {
        var tInit = ambient[0];
        var pInit = pressure[0];
        var tChecked = ambient[1];
        var pChecked = pressure[1];

        hInit = (((Math.pow((p0/pInit), (1/5.257)))-1)*(tInit + 273.15))/0.0065;
        hChecked = (((Math.pow((p0/pChecked), (1/5.257)))-1)*(tChecked + 273.15))/0.0065;
        h = hChecked - hInit;        
    }
    //check current altitude
    while (h>=0) {
        if (h>2) {   
            if (lockerState == 1) {
                msg.payload = "safe";
                return msg;
            } else if (lockerState === 0) {
                msg.payload = "lock your belt!";
                //basically i want to send a 1 signal
                //to the buzzer which is a pin on the RPI3
                //so probably msg.payload = 1;
                return msg;
            }
        }
    }
} else return msg;

我的问题是系统无法存储初始数据t0，pr0从第一个环境和压力数组在不改变它的情况下打开。每次程序开始执行代码时，它都会改变t0和pr0。我想要实现的是当h小于0时改变初始数据。

如果有人可以分享如何解决这个问题的线索，将不胜感激

在Node-RED中存储数组中的值而不更改它

0 个答案: