31results about How to "Improve emergency braking effect" patented technology

The invention discloses a distributed drive electric automobile brake anti-lock control method and system. The method comprises the following steps: filtering the current speed of an automobile by adopting unscented Kalman filtering; determining the current slip rate of each wheel according to the current speed of the automobile; calculating the current utilization adhesion coefficient of each wheel of the automobile; inputting the current slip rate and the current utilization attachment coefficient into an adaptive neural network model to obtain the optimal slip rate and the maximum utilization attachment coefficient of the current pavement; according to Thb = (mumaxFz-Freg) r, calculating the magnitude of braking torque Thb, needing to be provided by a hydraulic braking system, of each wheel to be recorded as first braking torque; according to Teb = TSMC-Thb, calculating the magnitude of the braking torque Teb, needing to be provided by a hub motor of each wheel, of each wheel to berecorded as a second braking torque; and in the anti-lock braking process of the automobile, controlling the braking torque output by the hydraulic braking system and the braking torque output by eachwheel hub motor according to the first braking torque and the second braking torque. The emergency braking effect is improved.

The invention discloses a high-dynamic-response flux-weakening speed extension method of a permanent magnet synchronous motor, comprising the steps of comparing, by a flux-weakening function module, omega<*> and omega continuously with omega<*> and omega; if comparison results meet a condition, allowing an enable signal ENABLE to be 1, and enabling a d-axis speed regulator to finish a function where when it is given according to an error of omega<*> and omega that d-axis current given i<*><d> does not meet the condition, not activating the enable signal, wherein the d-axis current given i<*><d>=0 is vector having traditional d-axis current being zero; subjecting d-axis and q-axis current given i<*><d> and i<*><q> respectively to d-axis and q-axis current regulators, calculating with the regulators to give d-axis voltage u<d1> and q-axis voltage u<q1>, and processing the d-axis voltage u<d1> and q-axis voltage u<q1>, by a synthetic voltage amplitude-limiting module with d-axis voltage reserving, to obtain u<d> and u<q>. The method has the advantages that high-dynamic flux-weakening speed extension control similar to traditional vector control in speed loop performance can beprovided, no oscillations occur during the control process, and the high-dynamic flux-weakening speed extension control and the traditional vector control can be seamlessly switched.

The embodiment of the invention provides a vehicle active emergency braking system and method and a truck, and relates to the technical field of vehicle emergency braking. The vehicle active emergencybraking system comprises an electronic control device, a distance monitoring device, a vehicle monitoring device, a driving monitoring device and a pneumatic braking control device, wherein the distance monitoring device, the vehicle monitoring device, the driving monitoring device and the pneumatic braking control device are connected with the electronic control device respectively; the electronic control device computes compulsive braking distance according to the distance between a vehicle and a barrier, the vehicle speed, the load capacity and driving information, and judges whether the distance between the vehicle and the barrier is smaller than the compulsive braking distance or not, and according to the driving information, whether effective operation exists or not is judged; whenthe distance between the vehicle and the barrier is smaller than the compulsive braking distance, and when effective operation does not exist, the electronic control device controls an active brakinggas circuit to be started to carry out active braking. According to the vehicle active emergency braking system and method and the truck in the embodiment, response time of the vehicle active brakingsystem is shortened, emergency braking efficiency is improved, and the safety performance of the vehicle is improved.

The invention particularly relates to a new energy vehicle brake sensing and pedal position active adjusting type pedal mechanism. The mechanism comprises a brake pedal, a brake rod, a pedal sensing simulator, a support and a push rod device, wherein the brake pedal is rotationally connected with one end of the brake rod through a stepping motor, and the other end of the brake rod is rotationally connected with the support; an angle sensor is arranged between the brake rod and the support, and a pre-induction sensor is arranged on the brake pedal; the pedal feeling simulator comprises a magnetorheological fluid damper and a spring damper, and the spring damper comprises a spring shell and a damping spring arranged in the spring shell; the magnetorheological fluid damper comprises a magnetorheological fluid shell, a damping piston, magnetorheological fluid and a coil, the damping piston, the magnetorheological fluid and the coil are arranged in the magnetorheological fluid shell, the damping piston moves front and back, the magnetorheological fluid shell is fixedly connected with the spring shell and the support, and a damping piston rod penetrates through the spring shell in a sliding mode and is rotationally connected with the brake rod; the damping piston rod is provided with a limiting piece for adjusting the pre-tightening force of the damping spring; the push rod device drives the support to move back and forth.

The invention discloses an engineering vehicle chassis brake control system and a crane, and relates to the technical field of engineering vehicles. The technical problem that braking capacity in the prior art is poor is solved. The engineering vehicle chassis brake control system comprises a foot brake valve, a first foot relay valve, a three-shaft left brake chamber, a three-shaft right brake chamber and a first air tank, and an air inlet of the first foot relay valve is communicated with an air outlet of the first air tank. One of two air outlets of the first foot relay valve is communicated with a travelling brake airflow inlet of the three-shaft left brake chamber. The other of the two air outlets of the first foot relay valve is communicated with a travelling brake airflow inlet of the three-shaft right brake chamber. The crane comprises a rear axle brake air path, and the rear axle brake air path comprises the engineering vehicle chassis brake control system. The engineering vehicle chassis brake control system and the crane are used for improving the brake performance of the chassis brake control system of the crane.

The invention provides a retractable emergency brake fin stabilizer for a ship. The fin stabilizer comprises a fin stabilizer body (1), an auxiliary fin (3), a hydraulic cylinder (4), a hydraulic motor (5), an oil pipeline (6) and a hydraulic oil pump (7). The fin stabilizer is characterized in that the fin stabilizer body (1) is of an inner cavity structure, a notch is formed in the bottom of the cavity, the notch is matched with the auxiliary fin (3), the two sides of the auxiliary fin (3) are provided with guide rails which are connected with the two sides of the fin stabilizer body (1) in a sliding mode, the hydraulic cylinder (4) is fixed to the inner wall of the cavity of the fin stabilizer body (1), the hydraulic oil pump (7) is communicated with the hydraulic cylinder (4) through the oil pipeline, power for reciprocating movement of the auxiliary fin (3) is provided, the hydraulic motor (5) is fixed to one side of the fin stabilizer body (1) and is communicated with the hydraulic oil pump (7) through the oil pipeline (6), the hydraulic oil pump (7) drives the hydraulic motor (5) to rotate and output torque, power allowing the fin stabilizer body (1) to swing in the vertical plane where the center axis is located is provided, and the fin stabilizer body is further used, so that an emergency brake function is added on the basis that the original stabilizing function of the fin stabilizer is not affected, the fin stabilizer is used to the largest extent, and the aim of braking the ship in emergencies through the fin stabilizer is achieved.

An improved environment-friendly dust removal device comprises a dust removal rack and a cleaning wheel, wherein a cleaning bristle brush sleeves an outer circular ring of the cleaning wheel, an installing plate is arranged above the dust removal rack, the dust removal rack is fixedly connected with the installing plate through a fixing rod, an upward extending middle end groove with a downward mouth portion is formed in the dust removal rack, a steering shaft is rotatably arranged at the lower end of the middle end groove, the cleaning wheel is installed on the steering shaft, a placement cavity is formed in the dust removal rack and located on the right side of the middle end groove, the right end of the steering shaft extends into the placement cavity, a second toothing wheel is fixedlyinstalled at the right end, a first toothing wheel in matched connection with the second toothing wheel is also installed in the placement cavity, a first electric rotating machine is fixedly installed at the right end of the placement cavity, and the first toothing wheel is fixedly connected with a transmission shaft of the first electric rotating machine.

The invention relates to a snow tire. The snow tire comprises a tire body, a cord ply, a belt ply and a tread; at least four longitudinal grooves, which extend in the circumferential direction of thetire body, are formed in the tread; the number of the longitudinal grooves is an even number; and the longitudinal grooves are symmetrically formed relative to the center line of the thread and are shaped like broken lines. Therefore, the cut-in capacity of the tire is improved so that the anti-skid performance on snow is improved and the operability is enhanced. In addition, as the widths and bending angles of the two longitudinal grooves close to the center line of the tread are smaller than those of the rest longitudinal grooves, the middle position of the tread realizes better guidance quality; and as the tread of an area close to the external side realizes larger ground grip force, the side slip prevention performance is improved.

The invention discloses an emergency braking device of a wrap yarn machine, relates to the technical field of braking structures, solves the problems that the probability of dangerous accidents is high and the overall safety performance of an existing wrap machine is low due to the fact that the existing wrap machine cannot achieve emergency braking, and comprises a supporting base which is connected to a supporting bottom plate and used for installing a rotating disc. The turntables are connected with the yarn covering roller through detachable connecting pieces, and the turntables are connected to the two sides of the yarn covering roller; an annular groove is formed in the rotary disc, a brake plate is connected to the supporting base through a pushing structure, a brake block connected with the annular groove in a clamped mode is connected to the brake plate, and friction plates are connected to the interior of the annular groove and the brake block. The annular groove and the brake block are connected with limiting blocks through first electric telescopic rods. The pushing structure and the first electric telescopic rod are both in communication connection with the PLC. According to the emergency braking structure, the friction plate and the limiting block which are connected are matched with each other and have a synergistic effect, the braking time is shortened, and the braking effect of emergency braking is improved.

The invention discloses a vehicle speed control method and device, and vehicle electric control equipment. Wherein, the method includes: when receiving the deceleration command, detecting the current vehicle speed value of the target vehicle; determining the vehicle speed prediction model and the target deceleration parameters, wherein the vehicle speed prediction model is used to predict the vehicle speed control parameters of the target vehicle in the future preset time period , the target deceleration parameters at least include: deceleration time length, deceleration control time domain, deceleration prediction time domain and deceleration difference; determine the deceleration reference amount of the target vehicle during deceleration, wherein the deceleration reference amount is used to indicate that the target vehicle is calculated according to the deceleration time length The deceleration distribution value when the vehicle decelerates; based on the target deceleration parameter, the vehicle speed control parameter and the deceleration reference value, the target vehicle is controlled to decelerate from the current vehicle speed value to the vehicle speed set value. The invention solves the technical problem that when the vehicle is in emergency braking, the sudden increase in vehicle speed will be caused by the fixed deceleration until the deceleration is performed, reducing the emergency braking effect.

The invention discloses a humidifier with an emergency circuit protection device. A cover body and a machine body are included. An annular block with a thread on an outer side surface is fixedly arranged on a top surface of the machine body. The cover body and the machine body can be fixedly connected through the annular block. A water storage cavity which is provided with an upward opening and can be used for storing water is arranged in the machine body. Two spray cavities which are symmetrical left and right, are connected with the outside world and can be used for spraying air are arrangedin the cover body. A through cavity is arranged in a lower side of the water storage cavity. A sliding cavity is arranged in a left side of the through cavity in a connection manner. A threaded sleeve capable of sealing the through cavity is arranged in the sliding cavity in a sliding manner. In the invention, an emergency braking capacity can be improved through an emergency circuit control system and a transmission mechanism when the humidifier encounters a water leakage phenomenon, a motor and a heater can be prevented from being burnt out due to a short circuit problem of a circuit, and safety is greatly improved.

The invention discloses an automatic transmission gear shifting amendment control method for improving vehicle emergency braking performance. The automatic transmission gear shifting amendment control method is characterized in that when a vehicle provided with an automatic transmission is subjected to emergency braking, through gear amendment of the automatic transmission and rotating speed adjustment and the braking torque characteristic of an engine, the braking distance during vehicle emergency braking is shortened, and abrasion of a braking system is reduced.

The invention discloses a non-friction type brake which comprises a moving part, a braking part and a non-friction type braking mechanism. The moving part and the braking part are arranged together coaxially in a sleeved mode and are matched in a rotating mode. Wheel teeth are arranged on the rotating matching face of the braking part. The non-friction type braking mechanism comprises a floating block which is arranged on the rotating matching face of the moving part in a floating mode in the radial direction and is in meshing transmission with the wheel teeth. The tangential direction angle of the action points of the floating block and the wheel teeth is continuously changeable. The non-friction type braking mechanism is of a transmission structure in which the floating block and the wheel teeth are matched, meanwhile, the tangential direction angle of the action points of the floating block and the wheel teeth is continuously changeable in a certain range, continuously-changeable joining force is generated, when the tangential direction angle is large, equal-torque output can be achieved, torque transmission capacity is high, vehicle braking distance is shortened, emergency braking performance is improved, meanwhile, the floating block and the wheel teeth are matched in a non-friction mode, the problem that due to part abrasion, maintaining is frequent, and service life is short can be avoided, and operation cost is lowered.

The invention provides an automobile emergency braking safety device. The device comprises a first injection valve, a baffle, a spring, a spark plug, a second injection valve, a piston, a brake nail,an electromagnet and an iron pin, and the first gas injection valve is assembled on the upper end surface of a brake body; the second injection valve is assembled on the upper end surface of the brakebody; the spark plug is assembled on the upper end surface of the brake body; the spring is assembled on the upper side in the brake body; the baffle is assembled on the upper side in the brake body,the piston is assembled in the brake body, the brake nail is assembled on the lower end face of the piston, the electromagnet is assembled on the upper end face of a supporting frame, and an iron pinis assembled on the left end face of the electromagnet. The design solves the problem that the original automobile emergency brake effect is poor, the structure is reasonable, and the automobile emergency brake effect can be improved conveniently.

The invention discloses an emergency braking device for an elevator. The device comprises an elevator car, a traction steel rope is fixedly connected to the top of the elevator car, the part, on the two sides of the traction steel rope, of the top of the elevator car are fixedly connected with heightening blocks, sensing devices are arranged above the heightening blocks, the two sides of the elevator car are provided with braking positioning devices, and the braking positioning devices are installed in elevator shafts; and each sensing device comprises a first round pipe, the bottom of each first round pipe is fixedly connected to one corresponding heightening block, round rods are inserted into the first round pipes, one end of each round rod extends to one side of the traction steel rope, the end, close to the traction steel rope, of each round rod is movably connected with a rolling wheel, each rolling wheel is tangent to the traction steel rope, and a baffle sleeves the rod wall ofthe end, close to the traction steel rope, of each round rod. According to the emergency braking device for the elevator, the falling potential energy of the elevator car is buffered through a top end buffering device and a bottom buffering device, and the elevator car is stopped finally, and casualties caused by immediate falling of the car are avoided.

The invention discloses a multifunctional brake device for a vehicle, and belongs to the field of a vehicle brake device. The multifunctional brake device comprises an emergency brake device, a driving brake device, and an assistant brake device; on the basis of not weakening the brake effect, the probability of locking state in the emergency brake process is greatly reduced, thus the vehicle cannot be unstable for being locked during the emergency brake while also can control the vehicle steering; moreover, requirements of the driving brake on a brake pad and brake oil are reduced, and sensing deviation generated in a long-term occlusion and wear process is slowed down; meanwhile, the vehicle inertial overturning is effectively inhibited, and the adaption performance of vehicles in the face of different road conditions is increased. Through the organic combination of the emergency brake device, the crane travelling device, and the assistant brake device, the vehicle ground grabbing performance is strengthened, the vehicle gravity stability is improved, and the vehicle adaptation to different road conditions is increased; meanwhile, wear of every part of brake device is reduced through the combination of different brake devices.

The invention discloses an engineering vehicle chassis brake control system and a crane, and relates to the technical field of engineering vehicles. The technical problem that braking capacity in the prior art is poor is solved. The engineering vehicle chassis brake control system comprises a foot brake valve, a first foot relay valve, a three-shaft left brake chamber, a three-shaft right brake chamber and a first air tank, and an air inlet of the first foot relay valve is communicated with an air outlet of the first air tank. One of two air outlets of the first foot relay valve is communicated with a travelling brake airflow inlet of the three-shaft left brake chamber. The other of the two air outlets of the first foot relay valve is communicated with a travelling brake airflow inlet of the three-shaft right brake chamber. The crane comprises a rear axle brake air path, and the rear axle brake air path comprises the engineering vehicle chassis brake control system. The engineering vehicle chassis brake control system and the crane are used for improving the brake performance of the chassis brake control system of the crane.

A novel air purification device comprises a fixed frame and a rotary impeller. The four corners of the left end face and the right end face of the fixed frame are provided with fixed corners at the same time. A bolt hole is formed in each fixed corner. A rotary groove with a downward through opening is formed in the fixed frame, wherein the rotary groove extends upwards. A through connection shaft is rotationally mounted at the lower end of the rotary groove. The rotary impeller is mounted on the through connection shaft. A placement cavity is formed in the position, located on the right side of the rotary groove, in the fixed frame. The right end of the through connection shaft extends into the placement cavity and is fixedly provided with a second tooth wheel. A first tooth wheel connected with the second tooth wheel in a matched manner is further mounted in the placement cavity. A first motor is fixedly mounted at the right end of the placement cavity. The first tooth wheel is fixedly connected with a conveying shaft of the first motor. A bearing device is arranged on the outer side of the first motor and comprises vibration removal thick plates and heat reduction aluminum sheets.

The invention discloses an improved air purifying device. The improved air purifying device comprises a fixed frame and a rotating impeller; fixed angles are synchronously arranged at four corners ofthe end surfaces of the left and right sides of the fixed frame; bolt holes are formed in the fixed angles; a rotating groove with a downward through port and upwards extending is formed in the fixedframe; a transfer shaft is rotationally mounted at the lower end of the rotating groove; the rotating impeller is mounted on the transfer shaft; the fixed frame is provided with a placing cavity on the right side of the rotating groove; the right end of the transfer shaft extends into the placing cavity, and a second tooth wheel is fixedly mounted at the right end; a first tooth wheel matched andconnected with the second tooth wheel is mounted in the placing cavity; a first motor is fixedly mounted at the right end of the placing cavity; and the first tooth wheel is fixedly connected with a transfer shaft of the first motor.

The invention discloses a new-generation passenger vehicle-mounted internal and external integrated braking system. The integrated braking system comprises an external brake system assembly, an internal brake system assembly, an integrated control system, an vehicle body and frame assembly and a sensor assembly, wherein the external brake system assembly, the internal brake system assembly, the integrated control system and the sensor assembly are all assembled on the vehicle body and frame assembly, the external brake system assembly, the internal brake system assembly and the sensor assemblyare all connected to the integrated control system. The sensor assembly is further connected to the internal brake system assembly, the sensor assembly can transmit collected data to the internal brake system assembly and the integrated control system in real time, and the integrated control system controls the work of the external brake system assembly and the internal brake system assembly. Thebeneficial effects are that: through reasonable matching of the integrated control system and the sensor assembly, cooperative operation and integrated control of all the assemblies in the vehicle-mounted internal and external braking system are realized.

The invention provides an active braking system capable of realizing autonomous emergency braking. The active braking system comprises a high-pressure oil supply unit and a dual-channel braking wheel cylinder. The high-pressure oil supply unit is connected to the braking wheel cylinder through an active braking pipeline and a conventional braking pipeline. The active braking pipeline is provided with a second switch solenoid valve and a one-way valve. The conventional braking pipeline is provided with an anti-lock braking system. An oil storage cup is connected between the high-pressure oil supply unit and the anti-lock braking system through a pipeline and mounted on the top of a braking master cylinder. The active braking pipeline and the braking wheel cylinder are each provided with a hydraulic signal collector. A first oil hole and a second oil hole are formed in the braking wheel cylinder. The second oil hole and a first switch solenoid valve are integrated in the braking wheel cylinder. The anti-lock braking system comprises a three-position three-way solenoid valve. The first switch solenoid valve, the second switch solenoid valve, the three-position three-way solenoid valve and the hydraulic signal collectors are connected with a braking controller. The response time of the active braking system can be shortened, and the emergency braking performance is thus improved.

The invention relates to a drill jumbo travelling emergency braking system and a braking method thereof. The braking system comprises a main pump, a prefill valve connected with the main pump, an energy storage unit connected with the prefill valve, a stopping / emergency braking valve connected with the prefill valve, and a lay-up brake connected with the stopping / emergency braking valve. The stopping / emergency braking valve comprises a magnetic valve and an electric pressure switch connected with the magnetic valve. The electric pressure switch defines a switching point pressure value and a switch restoring point pressure value. The electric pressure switch judges whether a braking system requires emergency braking by judging the magnitude of a system pressure value of the braking system.Via the pressure judgment, extra wear of the lay-up brake caused by the emergency braking system after long-time use of a drill jumbo can be effectively prevented, so the service life of the lay-up brake is improved and safety hazards are prevented.

The invention discloses a distributed drive electric automobile brake anti-lock control method and system. The method comprises the following steps: filtering the current speed of an automobile by adopting unscented Kalman filtering; determining the current slip rate of each wheel according to the current speed of the automobile; calculating the current utilization adhesion coefficient of each wheel of the automobile; inputting the current slip rate and the current utilization attachment coefficient into an adaptive neural network model to obtain the optimal slip rate and the maximum utilization attachment coefficient of the current pavement; according to Thb = (mumaxFz-Freg) r, calculating the magnitude of braking torque Thb, needing to be provided by a hydraulic braking system, of each wheel to be recorded as first braking torque; according to Teb = TSMC-Thb, calculating the magnitude of the braking torque Teb, needing to be provided by a hub motor of each wheel, of each wheel to berecorded as a second braking torque; and in the anti-lock braking process of the automobile, controlling the braking torque output by the hydraulic braking system and the braking torque output by eachwheel hub motor according to the first braking torque and the second braking torque. The emergency braking effect is improved.

The invention discloses a piston type retarding braking system for a truck, and relates to the technical field of vehicle braking. The key points of the technical scheme are as follows: the piston type retarding braking system for the truck comprises an engine, a power shaft for transmitting the power of the engine, a gearbox for receiving the transmission of the power shaft, disc brakes arrangedon the power shaft, a rear axle, and piston type brakes used for braking the rear axle. The piston type brakes are used for replacing existing drum type brakes, and thus the effect of overcoming the defects of the existing drum type brakes is achieved.

The invention discloses an emergency braking device with an auxiliary braking function for a vehicle and belongs to the field of vehicle braking. The emergency braking device with the auxiliary braking function for the vehicle comprises emergency braking mechanisms arranged at front wheels and rear wheels of the vehicle and an auxiliary braking mechanism arranged at the bottom of the vehicle, wherein the emergency braking mechanisms comprise braking plates, outer side braking buckles, inner side braking pads and supporting wings; each outer braking buckle is nested in one side of the corresponding braking plate and positioned at the outer side of the corresponding front wheel and the corresponding rear wheel; each inner braking pad is arranged at the other side of the corresponding brakingplate and positioned at the inner side of the corresponding front wheel and the corresponding rear wheel; and the auxiliary braking mechanism comprises vortex fans arranged at the bottom of a chassisof the vehicle. Under the premise of not weakening the braking effect, the emergency braking device with the auxiliary braking function for the vehicle greatly reduces the probability of locking states during the emergency braking, so that the vehicle are not liable to instability caused by locking and can be steered during the emergency braking. At the same time, the use of the auxiliary brakingmechanism effectively restrains the vehicle from overturning caused by inertia and improves the adaptability to different road conditions of the vehicle.

The invention discloses an air purifying device which comprises a fixing frame and a rotating impeller. Fixing corners are simultaneously arranged at the four corners of the left end face and the right end face of the fixing frame. Bolt holes are formed in the fixing corners. A rotating groove extending upwards is formed in the fixing frame, wherein a through opening of the rotating groove faces downwards. The lower end of the rotating groove is rotationally provided with a rotating shaft, and the rotating impeller is installed on the rotating shaft. A containing cavity is formed in the position, located on the right side of the rotating groove, in the fixing frame. The right end of the rotating shaft extends in the containing cavity and is fixedly provided with a second cone tooth wheel, and a first tooth wheel cooperatively connected with the second tooth wheel is further installed in the containing cavity. A first motor is fixedly installed at the right end of the containing cavity, and the first tooth wheel is fixedly connected with a transmission shaft of the first motor.

The invention discloses an air purifying device which comprises a fixing frame and a rotating impeller. Fixing corners are simultaneously arranged at the four corners of the left end face and the right end face of the fixing frame. Bolt holes are formed in the fixing corners. A rotating groove extending upwards is formed in the fixing frame, wherein a through opening of the rotating groove faces downwards. The lower end of the rotating groove is rotationally provided with a rotating shaft, and the rotating impeller is installed on the rotating shaft. A containing cavity is formed in the position, located on the right side of the rotating groove, in the fixing frame. The right end of the rotating shaft extends in the containing cavity and is fixedly provided with a second cone tooth wheel, and a first tooth wheel cooperatively connected with the second tooth wheel is further installed in the containing cavity. A first motor is fixedly installed at the right end of the containing cavity, and the first tooth wheel is fixedly connected with a transmission shaft of the first motor.

The invention discloses a high-dynamic-response flux-weakening speed extension method of a permanent magnet synchronous motor, comprising the steps of comparing, by a flux-weakening function module, omega<*> and omega continuously with omega<*> and omega; if comparison results meet a condition, allowing an enable signal ENABLE to be 1, and enabling a d-axis speed regulator to finish a function where when it is given according to an error of omega<*> and omega that d-axis current given i<*><d> does not meet the condition, not activating the enable signal, wherein the d-axis current given i<*><d>=0 is vector having traditional d-axis current being zero; subjecting d-axis and q-axis current given i<*><d> and i<*><q> respectively to d-axis and q-axis current regulators, calculating with the regulators to give d-axis voltage u<d1> and q-axis voltage u<q1>, and processing the d-axis voltage u<d1> and q-axis voltage u<q1>, by a synthetic voltage amplitude-limiting module with d-axis voltage reserving, to obtain u<d> and u<q>. The method has the advantages that high-dynamic flux-weakening speed extension control similar to traditional vector control in speed loop performance can beprovided, no oscillations occur during the control process, and the high-dynamic flux-weakening speed extension control and the traditional vector control can be seamlessly switched.

The invention discloses a piston type retarding braking system for trucks, which relates to the technical field of vehicle braking. Disc brakes on the rear axle and piston brakes on the rear axle. The invention has the effect of overcoming the defects of the existing drum brake by replacing the existing drum brake with the piston brake.