The Sufficient and Necessary Condition to Make a Chair Steady on Uneven Ground;
在不平地面上把椅子放稳的充分必要条件
In order to apply the omni-directional vehicle with four Mecanum wheels to uneven ground,firstly it was presented that there were four sorts uneven ground and four class touch states between the Mecanum wheel and the four sorts uneven ground in common buildings.
为了在存在局部不平地面条件下应用Mecanum四轮全方位小车,总结出实际楼宇环境下存在的四类不平地面类型,分析给出对应于四种不平地面条件下Mecanum轮与地面的四种接触状态;针对四类接触状态,提出一种新的适应不平地面的Mecanum四轮全方位小车结构;用矢量及坐标变换方法解析了这种小车结构在不平地面条件下的运动学特性,分析给出了该小车的运动学条件及其适用范围;得出了该四轮小车在不平地面上运行的六维运动学模型。
Parallel to or in the plane of the horizon.
水平的与地平面平行的或在地平面中的
The working projection plane is taken at the equatorial plane corresponding to the ground surface.
工作投影面为赤道平面―相当于地平面。
a floor plan for the ground level of a building.
建筑地平面的一种平面图。
Sink below the horizon.
沉落到地平面以下。
the descent of a heavenly body below the horizon.
天体降落于地平面以下。
With the flat side down or in contact with a surface.
平平地，扁平地以扁平面向下或与另一平面接触
Above the level of the court
在场地(水平面)上
The floor is quite flat.
（室内的）地面很平。
Along a flat or even line or plane.
水平地沿水平面或水平线地
The land area and productive area of the Company is 30000 m2 and 15000 m2 respectively.
占地面积30000平方米，生产面积15000平方米。
On or up against a flat surface; at full length.
在平面上地或靠在平面上地;整个长度伸展地
A land area of uniform elevation.
平原，平地高度一致的地面
the rough texture of plowed fields.
犁过的田地的不平表面
The ground should even out soon.
地面应该马上平整好。
Quietly she faced her captors.
她平静地面对着追捕者。
The builders levelled the ground.
建筑者把地面弄平。
antenna height above average terrain
平均地表面上天线高度
press the soil flat with the back of a spade
用铲子的背面平整土地.