A control device of a dynamometer system is provided with: a driving force observer which estimates a generated driving force of a vehicle; an electrical inertia control unit which uses the driving force to generate a front wheel basic torque command signal and a rear wheel basic torque command signal; a synchronization control unit which generates a synchronization control torque command signal with respect to the basic torque command signal and the basic torque command signal in such a way as to eliminate a speed difference; and torque command signal generating units which use the synchronization control torque command signal to adjust the basic torque command signal and the basic torque command signal. The synchronization control unit is defined in such a way that the poles of a denominator polynomial of a transfer function from the driving force to the speed difference are all negative real numbers.

A vehicle longitudinal speed control testing apparatus includes a first movable target body spaced away from a vehicle executing active speed control while loaded by a dynamometer assembly, and a controller. The controller changes a distance between the first movable target body and the vehicle to cause a speed parameter of the vehicle to follow a desired vehicle speed schedule based on speed parameter feedback from the dynamometer assembly or the vehicle, a sum of a speed of the first movable target body and the speed parameter feedback to follow a desired absolute speed schedule, or the distance between the first movable target body and the vehicle to increase according to a desired distance schedule.

The device described herein and the associated method relate, in particular, to a holding device for a wind tunnel test stand 1, in particular for a wind tunnel balance. The device may comprise a holding base 5a, 6a, which may be arranged outside of a conveyor belt 3 of the wind tunnel test stand 1, and a support element 7 having at least two ends 7a, 7b. Via a connection element 13, one end of the support element 7 may be connected to a wheel 22 of a test object 4. Furthermore, a support device 8 may be provided, which may be connected to the support element 7 in such a way that a change in a rotational orientation of the support element 7 can cause a lifting or lowering movement of the support device 8.

Systems and methods for improving fuel economy in vehicles such as Class 8 trucks are provided. In some embodiments, signals indicating states of the powertrain are collected and used to generate fuel rate optimization values. Fuel rate optimization values may indicate a difference between optimum fuel flow rates and actual fuel flow rates during a vehicle drive cycle. Recorded fuel rate optimization values may be used to compare different vehicle configurations during testing, and may also be used to evaluate vehicle performance during real-world operation.

A test method for a vehicle powertrain includes, during a first test of a first vehicle or a portion of a first vehicle on a dynamometer, coordinatingly controlling (i) an accelerator pedal, an accelerator pedal signal, a fuel injector, a manifold pressure, a motor controller, or a throttle valve according to a load schedule and (ii) the dynamometer according to a speed schedule such that the dynamometer applies dynamic torque that causes a powertrain of the first vehicle or portion of the first vehicle to produce dynamic powertrain torque. The test method also includes recording values defining a history of the dynamic torque, and during a second test of the first vehicle or portion of the first vehicle on the dynamometer or another dynamometer, or during a second test of a second vehicle or a portion of a second vehicle on the dynamometer or another dynamometer, coordinatingly controlling (iii) an accelerator pedal, an accelerator pedal signal, a fuel injector, a manifold pressure, a motor controller, or a throttle valve according to the values defining the history of the dynamic torque and (iv) the dynamometer or the another dynamometer according to the speed schedule such that the dynamometer or the another dynamometer applies dynamic torque that causes a powertrain of the first vehicle or portion of the first vehicle or a powertrain of the second vehicle or portion of the second vehicle to reproduce the dynamic powertrain torque.

The present invention is one that reproduces behavior close to an actual run of a vehicle in a test using a loading device, and is a specimen test apparatus that tests a specimen that is a vehicle or a part of a vehicle. The vehicle test apparatus includes; a loading device that is connected to a rotating shaft of the specimen and gives running resistance to the rotating shaft; a storage part that stores tire diameter data indicating the relationship between a running state of the specimen and a tire diameter; and a control part that, from the tire diameter data, calculates a tire diameter corresponding to a running state of the specimen, and controls the loading device with use of running resistance obtained from the calculated tire diameter.

A vehicle information calculation apparatus includes a motor torque acquisition unit, an angular acceleration acquisition unit, a contact force acquisition unit, and an inertia moment calculator. The motor torque acquisition unit acquires a torque of a motor that drives a vehicle. The angular acceleration acquisition unit acquires an angular acceleration of the motor. The contact force acquisition unit acquires a contact force of a wheel of the vehicle. The inertia moment calculator calculates an inertia moment of a rotating system of the vehicle including the wheel on the basis of the torque acquired by the motor torque acquisition unit, the angular acceleration acquired by the angular acceleration acquisition unit, the contact force acquired by the contact force acquisition unit, and a coefficient of friction between the wheel of the vehicle and a contact surface.

A method and vehicle test stand comprising at least one actuator for moving the vehicle in a longitudinal direction. During the test, a rotational movement which is carried out by a wheel or a powertrain of the vehicle is measured in real time, a longitudinal acceleration corresponding to the measured rotational movement is ascertained, and the at least one actuator is actuated based on the ascertained longitudinal acceleration. In at least one example, the vehicle may be connected to an acceleration sensor, an acceleration signal of the acceleration sensor is detected during the test and a low-frequency longitudinal acceleration component is calculated based on the ascertained longitudinal acceleration and a position control loop for controlling the actuator, and the vehicle longitudinal acceleration is ascertained based on the detected acceleration signal and the calculated low-frequency longitudinal acceleration component .

A test method for a vehicle powertrain includes, during a first test in which dynamic engine torque from a powertrain drives a vehicle on a road, recording throttle position or accelerator pedal position to define a throttle schedule, and recording engine speed to define an engine speed schedule. The test method further includes, during a second test of a vehicle engine, controlling a dynamometer and the vehicle engine according to the engine speed schedule and throttle schedule to reproduce the dynamic engine torque.

To subject a test object during a test run on a test bench to real environmental and/or surrounding conditions, particularly thermal conditions, it is provided that at least one temperature is measured at a measurement point as a measured variable during the test run on the test bench. At least one test object component of the test object is subdivided in a number of segments. The thermal interaction of at least one segment with the environment of the vehicle is simulated during the test run by a thermal simulation model of the simulation model. The thermal simulation model calculates the segment heat flow that is supplied to or dissipated from the at least one segment. This segment heat flow is adjusted as a function of the measured temperature at the test bench on at least one segment by means of a number of heat flow actuators.