     //전진 모터 가속
     if( ch == 'w' )
     {
-      rc_pwm_L = constrain(rc_pwm_L++, 100, 2000);
-      rc_pwm_R = constrain(rc_pwm_R++, 100, 2000);
+      rc_pwm_L = constrain(rc_pwm_L++, 0, 2000);
+      rc_pwm_R = constrain(rc_pwm_R++, 0, 2000);
       RovServo[0].write(rc_pwm_L);
       RovServo[2].write(rc_pwm_R);
       Serial.println("Left=");

    //좌회전
    if( ch == 'a' )
    {
      rc_pwm_L = constrain(rc_pwm_L--, 100, 2000);      
      rc_pwm_R = constrain(rc_pwm_R++, 100, 2000);
      RovServo[0].write(rc_pwm_L);    //좌측모터 출력 감소
      RovServo[2].write(rc_pwm_R);    //우측모터 출력 증가
      Serial.println("Left=");

    //상단모터 가속
    if( ch == 'q' )
    {
      rc_pwm_T = constrain(rc_pwm_T++, 0, 2000);
      RovServo[1].write(rc_pwm_T);  
      Serial.println("Top=");
      Serial.println(rc_pwm_T);
