基于GGAP-RBF的重型载货汽车持续制动匹配分级控制策略

Graded Control Strategy of Continuous Brake Matching for Heavy Duty Truck Based on GGAP-RBF

为了有效降低长大下坡路段重型载货汽车行车制动器的使用频率和驾驶强度,基于持续制动匹配等级和广义生长剪枝径向基函数(GGAP-RBF)减速度估计模型提出持续制动匹配控制策略。首先以重型载货汽车为研究对象,基于发动机制动、排气制动和电涡流缓速器制动试验研究持续制动力随行驶车速的变化关系;然后以当前车速、车速差以及道路坡度作为输入参数,需求减速度作为输出参数,基于GGAP-RBF建立需求减速度估计模型;最后依据需求制动力与等级制动力差值最小原则选择持续制动匹配等级,同时分别进行定坡度工况下试验验证和变坡度工况下仿真研究以验证控制效果。结果表明:4.2%定坡度工况下,采用所提出的控制策略持续制动等级仅切换2次,比控制最优驾驶人切换少1次,速度变化基本一致;13 160m变坡度工况下,能够实现稳定减速,150m后达到预定车速,随后在60~62km·h^(-1)范围内变化,具有变坡度工况适应性强的特点;所提出的控制策略能够依靠持续制动匹配分级控制而有效降低行车制动器的使用频率和驾驶强度,实现车辆减速和稳定车速下坡行驶的效果。

In order to effectively reduce the working frequency of service brake and labor intensity of the driver on long downhill sections for heavy duty truck,the graded control strategy was proposed based on the continuous braking matching level and the deceleration estimation model of the generalized growth and pruning radial basis function（GGAP-RBF）neural network.Firstly,regarding the heavy duty truck as a research object,the relation curve between continuous braking force and running speed was investigated,based on the tests of the engine braking,exhaust braking and eddy current retarder braking.Furthermore,the deceleration estimation model was established,based on GGAP-RBF neural network with the current speed,vehiclespeed difference and road gradient as input parameters and demand deceleration as output parameter.Then the minimum brake force difference between demanding braking force and level braking force was set to be the principle to match the braking levels.Finally,the validity of control strategy was verified by the mean of simulation and tests on the fixed slope and variable slope road conditions.The results show that with the same velocity changes under condition of slope of 4.2%,the continuous braking grade only shifts twice,by dint of the control strategy proposed in this paper,less than that of the experienced driver.Under the changing-slope working condition of 13 160 m,the velocity can decrease steadily and then reach the desired value after 150 m.Then the velocity ranges from 60 to 62 km·h-1.It can be seen that it holds the strong adaptability feature.The strategy proposed in this paper can reduce the service braking working frequency and drive intensity effectively on the basis of the continuous braking grading control,and velocity reduction and the velocity holding effectiveness on downhill condition can be achieved.