ardupilot/Tools/LogAnalyzer/tests/TestMotorBalance.py

from LogAnalyzer import Test,TestResult
import DataflashLog

from VehicleType import VehicleType

class TestBalanceTwist(Test):
    '''test for badly unbalanced copter, including yaw twist'''
    def __init__(self):
        Test.__init__(self)
        self.name = "Motor Balance"

    def run(self, logdata, verbose):
        self.result = TestResult()
        self.result.status = TestResult.StatusType.GOOD

        if logdata.vehicleType != VehicleType.Copter:
            self.result.status = TestResult.StatusType.NA
            return

        self.result.status = TestResult.StatusType.UNKNOWN
        if not "RCOU" in logdata.channels:
            return

        ch = []

        for i in range(8):
            for prefix in "Chan", "Ch", "C":
                if prefix+`(i+1)` in logdata.channels["RCOU"]:
                    ch.append(map(lambda x: x[1], logdata.channels["RCOU"][prefix+`(i+1)`].listData))

        ch = zip(*ch)
        num_channels = 0
        for i in range(len(ch)):
            ch[i] = filter(lambda x: (x>0 and x<3000), ch[i])
            if num_channels < len(ch[i]):
                num_channels = len(ch[i])

        if num_channels < 2:
            return

        try:
            min_throttle = logdata.parameters["RC3_MIN"] + logdata.parameters["THR_MIN"] / (logdata.parameters["RC3_MAX"]-logdata.parameters["RC3_MIN"])/1000.0
        except KeyError as e:
            min_throttle = logdata.parameters["MOT_PWM_MIN"] / (logdata.parameters["MOT_PWM_MAX"]-logdata.parameters["RC3_MIN"])/1000.0

        ch = filter(lambda x:sum(x)/num_channels > min_throttle, ch)

        if len(ch) == 0:
            return

        avg_all = map(lambda x:sum(x)/num_channels,ch)
        avg_all = sum(avg_all)/len(avg_all)
        avg_ch = []
        for i in range(num_channels):
            avg = map(lambda x: x[i],ch)
            avg = sum(avg)/len(avg)
            avg_ch.append(avg)

        self.result.statusMessage = "Motor channel averages = %s\nAverage motor output = %.0f\nDifference between min and max motor averages = %.0f" % (str(avg_ch),avg_all,abs(min(avg_ch)-max(avg_ch)))

        self.result.status = TestResult.StatusType.GOOD

        if abs(min(avg_ch)-max(avg_ch)) > 75:
            self.result.status = TestResult.StatusType.WARN
        if abs(min(avg_ch)-max(avg_ch)) > 150:
            self.result.status = TestResult.StatusType.FAIL