三车道驾驶模拟：实现单车道单列与半自动驾驶车道居中控制

Hey there! Let's work through this to get your 3-lane driving simulation set up exactly how you want it—single cars per lane, no overtaking, and solid lane-centering behavior. We'll tweak your existing place-cars-level0 and control-speed code step by step to hit these goals.

Step 1: Modify Vehicle Placement (place-cars-level0) #

First, we need to ensure exactly one car per lane instead of random placement. We'll define your 3 lanes per direction, then place one car in each lane with no adjacent cars (to enforce single-file) and disable random turns/stops for predictability.

; place-cars-level0 modified for 3-lane single-car per lane setup
to place-cars-level0
  ; Define your lane coordinates (adjust these to match your road's actual layout)
  let road-up-lanes [3 5 7]       ; X-coords for 3 upward-moving lanes
  let road-down-lanes [3 5 7]     ; X-coords for 3 downward-moving lanes
  let road-left-lanes [4 6 8]     ; Y-coords for 3 leftward-moving lanes
  let road-right-lanes [4 6 8]    ; Y-coords for 3 rightward-moving lanes

  ; Place 1 car in each upward lane
  foreach road-up-lanes [
    let lane-x ?
    ask one-of patches with [meaning = "road-up" and pxcor = lane-x] [
      ; Ensure no cars directly ahead/behind, and not near crossings
      if not any? cars-on patch pxcor (pycor + 1) 
      and not any? cars-here 
      and not any? cars-on patch pxcor (pycor - 1) 
      and not any? patches with [meaning = "crossing"] in-radius 2 [
        sprout-cars 1 [
          set size 3
          set will-turn? "no"       ; Disable turns to keep cars in lane
          set will-stop? "no"       ; Disable random stops for consistency
          set shape "car top"
          set politeness basic-politeness
          set heading 0
          set maxSpeed speed-limit  ; Consistent max speed for semi-autonomous behavior
          set speed maxSpeed - random 5  ; Slight initial speed variation
        ]
      ]
    ]
  ]

  ; Place 1 car in each downward lane
  foreach road-down-lanes [
    let lane-x ?
    ask one-of patches with [meaning = "road-down" and pxcor = lane-x] [
      if not any? cars-on patch pxcor (pycor + 1) 
      and not any? cars-here 
      and not any? cars-on patch pxcor (pycor - 1) 
      and not any? patches with [meaning = "crossing"] in-radius 2 [
        sprout-cars 1 [
          set size 3
          set will-turn? "no"
          set will-stop? "no"
          set shape "car top"
          set politeness basic-politeness
          set heading 180
          set maxSpeed speed-limit
          set speed maxSpeed - random 5
        ]
      ]
    ]
  ]

  ; Place 1 car in each leftward lane
  foreach road-left-lanes [
    let lane-y ?
    ask one-of patches with [meaning = "road-left" and pycor = lane-y] [
      if not any? cars-on patch (pxcor + 1) pycor 
      and not any? cars-here 
      and not any? cars-on patch (pxcor - 1) pycor 
      and not any? patches with [meaning = "crossing"] in-radius 2 [
        sprout-cars 1 [
          set size 3
          set will-turn? "no"
          set will-stop? "no"
          set shape "car top"
          set politeness basic-politeness
          set heading 270
          set maxSpeed speed-limit
          set speed maxSpeed - random 5
        ]
      ]
    ]
  ]

  ; Place 1 car in each rightward lane
  foreach road-right-lanes [
    let lane-y ?
    ask one-of patches with [meaning = "road-right" and pycor = lane-y] [
      if not any? cars-on patch (pxcor + 1) pycor 
      and not any? cars-here 
      and not any? cars-on patch (pxcor - 1) pycor 
      and not any? patches with [meaning = "crossing"] in-radius 2 [
        sprout-cars 1 [
          set size 3
          set will-turn? "no"
          set will-stop? "no"
          set shape "car top"
          set politeness basic-politeness
          set heading 90
          set maxSpeed speed-limit
          set speed maxSpeed - random 5
        ]
      ]
    ]
  ]
end

Key changes here:

• We explicitly define lanes by coordinate, so each lane gets exactly one car
• Disabled random turns/stops to keep cars in their lanes
• Simplified speed setup for more predictable semi-autonomous behavior

Step 2: Modify Speed Control (control-speed) #

Next, we'll strip out all overtaking logic and add lane-centering code. The goal is to keep cars following the vehicle ahead in their lane, with no attempts to pass left/right.

; control-speed modified for lane-keeping and no overtaking
to control-speed
  ; Check for cars directly ahead in the same lane
  let car-ahead one-of cars-on patch-ahead 4
  ; Block overtaking by checking left/right lanes ahead too
  let car-left-ahead any? cars-on patch-left-and-ahead 90 4
  let car-right-ahead any? cars-on patch-right-and-ahead 90 4

  ifelse car-ahead = nobody and not car-left-ahead and not car-right-ahead [
    ; Accelerate to max speed if we're below it
    if speed < maxSpeed [
      set speed speed + acceleration
    ]
  ] [
    ; If any car is ahead (same lane or adjacent), match speed to avoid overtaking
    if [speed] of car-ahead = 0 [
      set speed 0
    ] else [
      ; Stay at or below the lead car's speed, with a small deceleration for safe distance
      set speed min([speed] of car-ahead, maxSpeed)
      set speed speed - deceleration
    ]
  ]

  ; Lane-centering logic: keep the car in the middle of its lane
  ; Adjust these calculations to match your lane width/layout
  if meaning = "road-up" or meaning = "road-down" [
    ; For vertical lanes, calculate the lane's center X-coordinate
    let lane-center-x round(pxcor / 2) * 2 + 1
    ; Drifted left? Move right; drifted right? Move left
    if pxcor != lane-center-x [
      setxy (pxcor + (sign(lane-center-x - pxcor))) pycor
    ]
  ]

  if meaning = "road-left" or meaning = "road-right" [
    ; For horizontal lanes, calculate the lane's center Y-coordinate
    let lane-center-y round(pycor / 2) * 2 + 1
    ; Drifted down? Move up; drifted up? Move down
    if pycor != lane-center-y [
      setxy pxcor (pycor + (sign(lane-center-y - pycor)))
    ]
  ]
end

Key changes here:

• Removed all overtaking/laneswitching code
• Added checks for left/right ahead cars to block any accidental overtaking
• Added lane-centering logic that automatically nudges cars back to the lane center if they drift

Final Integration Tips #

1. Match Lane Coordinates: Update the road-up-lanes/etc. variables in place-cars-level0 to match your actual road's pixel coordinates.
2. Tweak Lane Centering: Adjust the lane-center-x/lane-center-y calculations if your lanes are wider/narrower than the example.
3. Set Car Count: Make sure num-of-cars-level0 is a multiple of 3 (e.g., 3, 6, 9) to match one car per lane.

内容的提问来源于stack exchange，提问作者Tom Best