Patent Description:
Many automotive manufacturers are strategically investing in research and development of intelligent vehicles. With the development of various supporting technologies and the implementation of related laws and regulations, the mass production of intelligent vehicles can be expected soon, and they will gradually come into our daily lives and finally become part of the future's highly safe intelligent transportation without manual intervention.

To date, we have witnessed increasing intelligence of passenger vehicles and the marketization of some passenger vehicles equipped with a L3 autonomy system a time ago. However, the intelligence of commercial vehicles seems to grow relatively slowly, and there have been no commercial vehicle models with autonomous driving capabilities seen in the marketplace. Nonetheless, this is not a reflection of unnecessary intelligence for commercial vehicles. On the contrary, potential reasons for this may include: bulky size, heavy weight and other limiting factors of commercial vehicles; a huge blind spot for the driver, which is relatively more likely to lead to traffic accidents, in particular, with vulnerable traffic participants such as non-motorized vehicles and pedestrians when turning or changing the lane; and typically serious injuries or death resulting from such accidents.

Therefore, design, research and development of intelligence technologies for commercial vehicles is necessary, and intelligent commercial vehicles with autonomous driving capabilities will also gradually replace human drivers. Future unmanned commercial vehicles will become safer traffic participants with a minimized risk of causing traffic accidents.

However, as commercial vehicles are significantly distinct from passenger vehicles in terms of, e.g., size, weight and driving properties, existing test facilities specially designed for assessing unmanned driving performance of intelligent passenger vehicles are not suited to commercial vehicles.

<CIT> discloses a test bench for aerodynamic measurements on vehicles which at least between the front and rear wheels of a vehicle extending center treadmill for simulating a situation under the vehicle between its wheels moving middle roadway area. <CIT> discloses a comprehensive performance test system for automated driving vehicles, comprising a base platform, a lateral moving platform which is mounted on the base platform and a rotary platform which is mounted on the lateral moving platform. <CIT> discloses a test bench for motor vehicles for generating rotary movements or rotational accelerations of the vehicle about its vertical axis. <CIT> discloses a vehicle testing instrument providing floor face simulating means corresponding to respective wheels of the vehicle to be tested and a turning electrical equipment which is directly coupled with the means and simulates the running resistance.

Therefore, there is proposed herein flat-belt type test benches for performing tests relating to the evaluation of unmanned driving capabilities of intelligent commercial vehicles.

In view of the above-described deficiencies with the prior art, it is an object of the present invention to provide flat-belt type test benches for commercial vehicles, which can satisfy the needs of practical applications.

To this end, the subject matter of the present invention lies in a flat-belt type test bench for commercial according to claim <NUM> and claim <NUM>.

In a preferred embodiment of the present invention, the limiting mechanism comprises a limiting disc, a fixed base, a pinion, an adjustment shaft, limiting shafts, limiting sleeves and threaded sleeves, the pinion rotatably coupled to the fixed base by a pinion shaft, the limiting shafts disposed symmetrically on both sides of the fixed base, both the adjustment shaft and the limiting shafts disposed horizontally, the adjustment shaft arranged above the pinion.

In a preferred embodiment of the present invention, the adjustment shaft is provided thereon with threads and configured for threaded engagement with the threaded sleeves by means of the threads, wherein the limiting sleeves are slidably disposed over the limiting shafts in symmetry with the threaded sleeves, and wherein linking rods are arranged in symmetry with each other on opposing surfaces of the respective threaded sleeves and of the respective limiting sleeves, and locking blocks are provided on the linking rods.

In a preferred embodiment of the present invention, the locking blocks are positioned at the same horizontal plane as the pinion, and locking notches are formed in the opposing surfaces of the respective two locking blocks.

In a preferred embodiment of the present invention, the limiting disc is disposed under, and fixed to, the rotary disc, and a number of second limiting teeth formed in an outer circumference of the limiting disc are configured to bring the limiting disc into engagement with the pinion.

In a preferred embodiment of the present invention, vehicle parameters input to the bench test system, including maximum power, maximum torque, turning radius, number of drive axles, number of steer axles, number of steering wheel turns and steer wheel angle, together with an autonomous driving robot and traffic scenarios created with various simulated traffic participants, enable multiple tests on autonomous driving capabilities of intelligent commercial vehicles, which can provide massive data that can support the development, testing and verification of unmanned driving capabilities of the intelligent commercial vehicles.

In a preferred embodiment of the present invention, the front axle flat-belt assemblies are further provided with a track adjustment mechanism configured to adjust the distance between the two front axle flat-belt assemblies so as to accommodate various wheel tracks and wheel bases of different commercial vehicles.

The present invention provides the beneficial effects as follows:.

In these <FIG> denotes the foundation; <NUM>, the main bench body; <NUM>, the mounting depression; <NUM>, an iron floor; <NUM>, a pivotal support base; <NUM>, an arc-shaped guide track; <NUM>, a main bench frame; <NUM>, the front axle flat-belt assembly; <NUM>, the rear axle flat-belt assembly; <NUM>, a fixed plate; <NUM>, a rotary disc; <NUM>, the limiting mechanism; <NUM>, a bench cover; <NUM>, the track adjustment mechanism; <NUM>, a double output shaft gear reducer; <NUM>, a second drive motor; <NUM>, a shaft coupling; <NUM>, a left-handed lead screw; <NUM>, a right-handed lead screw; <NUM>, a connecting seat; <NUM>, flat belt pulleys; <NUM>, a flat belt supporting base; <NUM>, a flat belt supporting roller set; <NUM>, flat belt supporting rollers; <NUM>, a flat belt; <NUM>, a first drive motor; <NUM>, a flat belt tensioning mechanism; <NUM>, a torque sensor; <NUM>, a pinion; <NUM>, first limiting teeth; <NUM>, a fixed base; <NUM>, limiting shafts; <NUM>, an adjustment shaft; <NUM>, a pinion shaft; <NUM>, threaded sleeves; <NUM>, limiting sleeves; <NUM>, a limiting disc; <NUM>, linking rods; <NUM>, locking blocks; <NUM>, locking notches; and <NUM>, second limiting teeth.

Embodiments of the present invention will be described below clearly and thoroughly with reference to the accompanying drawings. It is to be understood that the embodiments disclosed herein are only some but not all possible embodiments of the present invention. It is intended that any other embodiment made in light of the disclosed embodiments by those of ordinary skill in the art without paying creative effort also falls within the scope of the invention.

As shown in <FIG>, the present invention provides a flat-belt type test bench for commercial vehicles, which includes a main bench body <NUM> and a bench test system supporting and coordinating with the main bench body <NUM>.

As shown, the main bench body <NUM> includes a main bench frame <NUM> having a front section provided therein with a pair of front axle flat-belt assemblies <NUM> and a rear section provided therein with a pair of rear axle flat-belt assemblies <NUM>. Additionally, a pair of fixed plates <NUM> is provided on the front section of the main bench frame <NUM>, and rotatable rotary discs <NUM> are arranged on respective central portions of the fixed plates <NUM>. The front axle flat-belt assemblies <NUM> are mounted at respective centers of the rotary discs <NUM> on the fixed plates <NUM> so that they can rotate with the rotary discs <NUM>. Further, a track adjustment mechanism <NUM> is disposed between the two front axle flat-belt assemblies <NUM>, which can change the distance between the front axle flat-belt assemblies <NUM>, making it possible to accommodate various wheel tracks and wheel bases of different commercial vehicles. Furthermore, limiting mechanisms <NUM> are disposed external to the respective rotary discs <NUM> in order to limit their rotation during a test.

As shown in <FIG>, each front axle flat-belt assembly <NUM> includes a flat belt supporting base <NUM>, leading and trailing flat belt pulleys <NUM> disposed on opposing ends of the flat belt supporting base <NUM>, a flat belt supporting roller set <NUM> arranged above the flat belt supporting base <NUM> and a flat belt <NUM> surround both the leading and trailing flat belt pulleys <NUM> and the flat belt supporting roller set <NUM>. It would be readily appreciated that the flat belt supporting roller set <NUM> consists of a number of flat belt supporting rollers <NUM> arranged side by side and the number of them depends on the distance between the leading and trailing flat belt pulleys <NUM>. In addition, at least one of the flat belt pulleys <NUM> is provided therein with a first drive motor <NUM> for driving the flat belt pulley <NUM> to rotate, thus leading movement of the flat belt <NUM>. This arrangement is compact in structure. A torque sensor <NUM> is disposed on a side surface of one of the flat belt pulleys <NUM> and configured to detect a torque of the flat belt pulley <NUM>. A flat belt tensioning mechanism <NUM> is disposed at a side surface of one of the flat belt pulleys <NUM> and adapted to adjust a tension of the flat belt <NUM> in real time.

As shown in <FIG>, each rear axle flat-belt assemblies <NUM> is structured similarly to the front axle flat-belt assemblies <NUM> except for a flat belt supporting base <NUM> with a different length, i.e., a different spacing between leading and trailing flat belt pulleys <NUM>. Compared with traditional roller-type dynamometers, this flat-belt type test bench provides flat moving contact surfaces, which can better simulate actual wheel-to-road surface contact conditions and provide test setups that closely approximate actual environments. Therefore, tests performed and results thereof are of greater significance.

Additionally, as shown in <FIG>, the track adjustment mechanism <NUM> includes a double output shaft gear reducer <NUM>, a second drive motor <NUM>, a pair of shaft couplings <NUM>, a left-handed lead screw <NUM>, a right-handed lead screw <NUM>, a pair of nuts (not shown) and a pair of connecting seats <NUM>.

The double output shaft gear reducer <NUM> is fixed to the main bench frame <NUM> and coupled to the second drive motor <NUM>, with its output shafts being coupled respectively to the left- and right-handed lead screws <NUM>, <NUM> via the pair of shaft couplings <NUM>. The nuts are disposed in engagement respectively with the left- and right-handed lead screws <NUM>, <NUM> and are housed in the respective connecting seats <NUM>. Each connecting seat <NUM> is fixedly connected to the flat belt supporting base <NUM> of the front axle flat-belt assembly <NUM> arranged on the same side. Rotation of the second drive motor <NUM> is speed-reduced by the double output shaft gear reducer <NUM> and then transmitted in opposite directions to the left- and right-handed lead screws <NUM>, <NUM>, leading the nuts to rotate. As the lead screws rotate in opposite directions, the connecting seats <NUM> move simultaneously and symmetrically toward or away from each other. As a result, the respective front axle flat-belt assemblies <NUM> move correspondingly, achieving wheel track adjustments.

The design of this test bench follows a modular concept, in which an arbitrary number, e.g., one or two pairs, of front axle flat-belt assemblies <NUM> may be added, or a length of the rear axle flat-belt assemblies <NUM> may be altered, depending on the type of the commercial vehicle under test. In this way, the test requirements of commercial vehicles of various types can be met.

As shown in <FIG> and <FIG>, each limiting mechanism <NUM> includes a fixed base <NUM>, a pinion <NUM>, limiting shafts <NUM>, a pair of limiting sleeves <NUM>, an adjustment shaft <NUM>, a pair of threaded sleeves <NUM>, a pair of linking rods <NUM> and a pair of locking blocks <NUM>.

The pinion <NUM> is arranged above the fixed base <NUM> by a pinion shaft <NUM> and is rotatably coupled to the fixed base <NUM>.

The limiting shafts <NUM> are horizontally inserted into the fixed base <NUM> or otherwise disposed symmetrically on opposing sides of the fixed base <NUM>. The limiting sleeves <NUM> are disposed over the respective limiting shafts <NUM> on both sides of the fixed base <NUM>.

The adjustment shaft <NUM> is arranged above the pinion <NUM> so that it extends in parallel with the limiting shafts <NUM>. The adjustment shaft <NUM> is provided on its outer surface with threads, which run in opposite directions over different portions of the adjustment shaft <NUM>. Different portions are separated from each other at a middle point of the adjustment shaft <NUM> that is aligned with the underlying fixed base <NUM>. The threaded sleeves <NUM> are disposed over the respective opposite threaded portions and are aligned with the respective underlying limiting sleeves <NUM> on the limiting shafts <NUM>.

The linking rods <NUM> connect the respective upper threaded sleeves <NUM> to the respective lower limiting sleeves <NUM> that are vertically aligned with the respective threaded sleeves <NUM>, and the locking blocks <NUM> are disposed on the respective linking rods <NUM> at the same horizontal plane as the pinion <NUM>. Each locking block <NUM> defines a locking notch <NUM> at a location in positional correspondence with the pinion <NUM>, which is complementary in shape with first limiting teeth <NUM> on the pinion <NUM>. That is, the locking notch <NUM> can engage any of the first limiting teeth <NUM> on the pinion <NUM>.

A limiting disc <NUM> is disposed under, and fixedly connected to, the rotary disc <NUM>. The limiting disc <NUM> defines second limiting teeth <NUM> at locations along a peripheral edge thereof, which are in positional correspondence with the pinion <NUM> so as to be able to engage the first limiting teeth <NUM> thereon.

During a test, when the commercial vehicle drives straight or has turned to a desired angle, the adjustment shaft <NUM> of the limiting mechanism <NUM> rotates. Since the threads on the different halves of the adjustment shaft <NUM> run in opposite directions, the rotation of the threads causes movement of the threaded sleeves <NUM> on the different halves of the adjustment shaft <NUM> toward each other horizontally along the adjustment shaft <NUM>, which in turn drives movement of the locking blocks <NUM> toward each other. Upon the locking notches <NUM> of the locking blocks <NUM> moving into engagement with the first limiting teeth <NUM>, the pinion <NUM> will be locked, disallowing further rotation of the rotary disc <NUM> in engagement therewith. Thus, the rotary disc <NUM> is limited from further motion.

The main bench body <NUM> is mounted inside a foundation, or overall directly placed on the floor. Preferably, the main bench body <NUM> is mounted inside the foundation <NUM>, as shown in <FIG>. This makes it easy for a commercial vehicle under test to drive onto the test bench. The foundation <NUM> defines a generally sector-shaped mounting depression <NUM> with arc-shaped front and rear edges for allowing pivotal movement of the main bench body <NUM> within the mounting depression <NUM>. Specifically, with combined reference to <FIG>, an arc-shaped guide track <NUM> is provided at the front end of the foundation <NUM>, and an iron floor <NUM> is provided at the bottom thereof. At the bottom side of the main bench body <NUM>, guide wheels (not shown) and a pivotal support base <NUM> are provided in positional correspondence with the arc-shaped guide track <NUM> and the iron floor <NUM>, respectively. As a result, the main bench body <NUM> is able to pivot about the pivotal support base <NUM> within the mounting depression <NUM>, with the aid of the guide wheels moving on the arc-shaped guide track <NUM>. Further, as shown in <FIG>, a bench cover <NUM> is provided above the main bench body <NUM>, which is matched in shape with the mounting depression <NUM> and flush with the surface of the foundation <NUM>.

In this embodiment, the bench test system is implemented as a conventional one including a dynamometer test system, a hardware-in-the-loop simulation test system for complete vehicles and their subsystem assemblies, and a lower hierarchical control system. In addition, extension interfaces employing a common communication protocol are preserved for future functional extension. The dynamometer test system is capable of performance testing and emission testing. The hardware-in-the-loop simulation test system for complete vehicles and subsystem assemblies thereof works with an autonomous driving robot to carry out performance tests and hardware-in-the-loop simulations in relation to intelligent driving of complete vehicles, performance tests and hardware-in-the-loop simulations of subsystem assemblies, and the like. The lower hierarchical control system employs a distributed master-slave control scheme, standard industrial Ethernet communication and real-time control. Typical examples include Beckhoff TwinCat control systems and Ether-CAT buses. Control interfaces are preserved for each motion action in order to allow testing both under all the standard conditions prescribed for the proposed device and under user-defined special conditions for their specific applications made available on other compatible simulation platforms.

Claim 1:
A flat-belt type test bench for commercial vehicles, comprising a main bench body (<NUM>) and a bench test system, the main bench body (<NUM>) mounted inside a foundation (<NUM>), wherein the main bench body (<NUM>) comprises a main bench frame (<NUM>), a bench cover (<NUM>), front axle flat-belt assemblies (<NUM>) and rear axle flat-belt assemblies (<NUM>), each front axle flat-belt assembly (<NUM>) provided therein with a fixed plate (<NUM>), a rotary disc (<NUM>) and a limiting mechanism (<NUM>), wherein the fixed plate (<NUM>) is arranged on the front section of the main bench frame (<NUM>), with the rotary disc (<NUM>) being arranged on a central portion of the fixed plate (<NUM>) rotatably, and wherein the front axle flat-belt assembly (<NUM>) is arranged at center of the rotary disc (<NUM>) on the fixed plate (<NUM>), the limiting mechanism (<NUM>) disposed external to the rotary disc (<NUM>) and configured to limit rotation of the rotary disc (<NUM>) during a test, each rear axle flat-belt assembly (<NUM>) comprising a flat belt (<NUM>) and flat belt pulleys (<NUM>) both disposed within the flat belt at opposing ends thereof, wherein the foundation (<NUM>) defines a sector-shaped mounting depression (<NUM>) in which the main bench body (<NUM>) is mounted, with an iron floor (<NUM>) being arranged under the main bench body (<NUM>) and a pivotal support base (<NUM>) connecting the iron floor (<NUM>) to the main bench body (<NUM>), so that a top surface of the main bench body (<NUM>) is flush with a floor surface of the foundation (<NUM>), the mounting depression (<NUM>) provided at a front edge thereof with an arc-shaped guide track (<NUM>), the main bench body (<NUM>) provided at a front end thereof with guide wheels engaging the arc-shaped guide track (<NUM>), and wherein the main bench body (<NUM>) is configured to support thereon a commercial vehicle under test with front wheels resting on the front axle flat-belt assemblies (<NUM>) so that the front axle flat-belt assemblies (<NUM>) are able to turn independently with the steer wheels and rear wheels resting on the rear axle flat-belt assemblies (<NUM>).