ZSS support

Add ZSS support for Toyota Priuses with a Zorro Steering Sensor.

Credit goes to DragonPilot!

https: //github.com/dragonpilot-community/dragonpilot
Co-Authored-By: eFini <16603033+efinilan@users.noreply.github.com>
Co-Authored-By: Kumar <36933347+rav4kumar@users.noreply.github.com>

selfdrive/car/toyota/carstate.py

@@ -25,6 +25,8 @@ TEMP_STEER_FAULTS = (0, 9, 11, 21, 25)
 # - prolonged high driver torque: 17 (permanent)
 PERM_STEER_FAULTS = (3, 17)
 
+ZSS_THRESHOLD = 4.0
+ZSS_THRESHOLD_COUNT = 10
 
 class CarState(CarStateBase):
   def __init__(self, CP):
@@ -46,6 +48,11 @@ class CarState(CarStateBase):
     self.lkas_hud = {}
 
     # FrogPilot variables
+    self.zss_compute = False
+    self.zss_cruise_active_last = False
+
+    self.zss_angle_offset = 0
+    self.zss_threshold_count = 0
 
     self.traffic_signals = {}
 
@@ -222,6 +229,30 @@ class CarState(CarStateBase):
     SpeedLimitController.car_speed_limit = self.calculate_speed_limit()
     SpeedLimitController.write_car_state()
 
+    # ZSS Support - Credit goes to the DragonPilot team!
+    if self.CP.flags & ToyotaFlags.ZSS and self.zss_threshold_count < ZSS_THRESHOLD_COUNT:
+      zorro_steer = cp.vl["SECONDARY_STEER_ANGLE"]["ZORRO_STEER"]
+      # Only compute ZSS offset when acc is active
+      zss_cruise_active = ret.cruiseState.available
+      if zss_cruise_active and not self.zss_cruise_active_last:
+        self.zss_compute = True  # Cruise was just activated, so allow offset to be recomputed
+        self.zss_threshold_count = 0
+      self.zss_cruise_active_last = zss_cruise_active
+
+      # Compute ZSS offset
+      if self.zss_compute:
+        if abs(ret.steeringAngleDeg) > 1e-3 and abs(zorro_steer) > 1e-3:
+          self.zss_compute = False
+          self.zss_angle_offset = zorro_steer - ret.steeringAngleDeg
+
+      # Error check
+      new_steering_angle_deg = zorro_steer - self.zss_angle_offset
+      if abs(ret.steeringAngleDeg - new_steering_angle_deg) > ZSS_THRESHOLD:
+        self.zss_threshold_count += 1
+      else:
+        # Apply offset
+        ret.steeringAngleDeg = new_steering_angle_deg
+
     return ret
 
   def update_traffic_signals(self, cp_cam):
@@ -290,6 +321,8 @@ class CarState(CarStateBase):
     if CP.flags & ToyotaFlags.SMART_DSU:
       messages.append(("SDSU", 33))
 
+    messages += [("SECONDARY_STEER_ANGLE", 0)]
+
     return CANParser(DBC[CP.carFingerprint]["pt"], messages, 0)
 
   @staticmethod

selfdrive/car/toyota/interface.py

@@ -44,6 +44,9 @@ class CarInterface(CarInterfaceBase):
       ret.steerActuatorDelay = 0.12  # Default delay, Prius has larger delay
       ret.steerLimitTimer = 0.4
 
+      if 0x23 in fingerprint[0]:  # Detect if ZSS is present
+        ret.flags |= ToyotaFlags.ZSS.value
+
     ret.stoppingControl = False  # Toyota starts braking more when it thinks you want to stop
 
     stop_and_go = candidate in TSS2_CAR

selfdrive/car/toyota/values.py

@@ -46,6 +46,7 @@ class ToyotaFlags(IntFlag):
   HYBRID = 1
   SMART_DSU = 2
   DISABLE_RADAR = 4
+  ZSS = 8
 
 
 class CAR(StrEnum):