add section about vehicle's specification

Author: Shiye Shizhi

doc/2_vehicle_model/2_vehicle_model.md

@@ -189,4 +189,89 @@ class XYArray:
         return XYArray(translated_data)
 ```
 
-In this code, a given data to Constructor is x-y 2D array. Then, the data can be transformed based on the vehicle's position (x, y) and yaw angle. After the data was transformed, a new XYArray object with the transformed data is returned.  
+In this code, a given data to Constructor is x-y 2D array. Then, the data can be transformed based on the vehicle's position (x, y) and yaw angle. After the data was transformed, a new XYArray object with the transformed data is returned.  
+
+### 2.4.3 Specification class
+Implementing Vehicle's specification class as follow. This class is used to manage each parameters for the vehicle's control.  
+
+```python
+"""
+vehicle_specification.py
+
+Author: Shisato Yano
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).absolute().parent) + "/../visualization")
+from min_max import MinMax
+
+class VehicleSpecification:
+    """
+    Vehicle Specification parameters class
+    """
+    
+    def __init__(self, f_len_m=2.0, r_len_m=0.0, tire_r_m=0.3,
+                 tire_w_m=0.12, axle_half_m=0.5, color='k', 
+                 line_w=1.0, line_type='-', area_size=10.0,
+                 x_lim=MinMax(-30, 30), y_lim=MinMax(-30, 30),
+                 max_accel_mps2=3.0):
+        """
+        Constructor
+        f_len_m: length[m] from origin to center of front axle
+        r_len_m: length[m] from origin to center of rear axle
+        tire_r_m: tire's radius[m]
+        tire_w_m: tire's half of width[m]
+        color: vehicle's color
+        line_w: plot line's width
+        line_type: plot line's type
+        area_size: plot area size[m]
+        x_lim: min/max values of x-axis
+        y_lim: min/max values of y-axis
+        max_accel_mps2: maximum acceleration/deceleration[m/s2]
+        """
+
+        self.f_len_m = f_len_m
+        self.f_edge_m = self.f_len_m + 0.5
+
+        self.r_len_m = r_len_m
+        self.r_edge_m = self.r_len_m + 0.5
+
+        self.tread_m = 0.25 * (1.0 + self.f_len_m + self.r_len_m)
+        self.width_m = 1.0 * self.tread_m
+        self.wheel_base_m = self.f_len_m + self.r_len_m
+        
+        self.tire_r_m = tire_r_m
+        self.tire_w_m = tire_w_m
+        self.axle_half_m = axle_half_m
+
+        self.color = color
+        self.line_w = line_w
+        self.line_type = line_type
+        self.area_size = area_size
+
+        self.x_lim = x_lim
+        self.y_lim = y_lim
+
+        self.max_accel_mps2 = max_accel_mps2
+```
+
+The vehicle has the following parameters as specification.  
+
+* Length from origin to center of front axle[m]
+* Length from origin to center of rear axle[m]
+* Length from origin to edge of front body[m]
+* Length from origin to edge of rear body[m]
+* Length of Tread[m]
+* Body's width[m]
+* Length of wheel base[m]
+* Tire's radius[m]
+* Tire's width[m]
+* Half of axle length[m]
+* Drawing color
+* Type of line
+* Size of zoom area around vehicle[m]
+* Limitation in x axis[m]
+* Limitation in y axis[m]
+* Maximum acceleration[m/s2]