VW PQ: fix EPB rate limit

* update carAPI EMA (175 SMA eq)

selfdrive/car/volkswagen/carcontroller.py

@@ -32,6 +32,7 @@ def __init__(self, dbc_name, CP, VM):
     self.accel_last = 0
     self.motor2_frame = 0
     self.EPB_brake = 0
+    self.EPB_brake_last = 0
     self.EPB_enable = 0
     self.EPB_counter = 0
     self.accel_diff = 0
@@ -154,14 +155,15 @@ def update(self, CC, CS, now_nanos):
                                                                             # SMA to EMA conversion: alpha = 2 / (n + 1)    n = SMA-sample
       self.accel_diff = (0.0019 * (accel - self.accel_last)) + (1 - 0.0019) * self.accel_diff         # 1000 SMA equivalence
       self.long_deviation = interp(abs(accel - self.accel_diff), [0, .2, .3], [.13, .1, 0])           # floating comfort band calculation
-      self.long_ratelimit = (0.019 * (clip(abs(accel), 0.7, 3))) + (1 - 0.019) * self.long_ratelimit  # set jerk/rate limit based on accel
+      self.long_ratelimit = (0.011 * (clip(abs(accel), 0.7, 3))) + (1 - 0.011) * self.long_ratelimit  # set jerk/rate limit based on accel
 
       if self.CCS == pqcan and CC.longActive and actuators.accel <= 0 and CS.out.vEgoRaw <= 5:
         if not self.EPB_enable:
           self.EPB_counter = 0  # Reset frame counter when EPB_enable is first activated
           self.EPB_brake = 0
         else:
-          self.EPB_brake = clip(accel, self.accel_last - self.long_ratelimit, self.accel_last + self.long_ratelimit)
+          self.EPB_brake = clip(accel, self.EPB_brake_last - self.long_ratelimit, self.EPB_brake_last + self.long_ratelimit)
+          self.EPB_brake_last = self.EPB_brake
           self.EPB_enable = 1
       else:
         acc_control = 0 if acc_control != 6 and self.EPB_enable else acc_control  # Pulse ACC status to 0 for one frame